 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES DATE: July 9, 2003 MEMORANDUM TXR No. 0052006 SUBJECT: Mechanism of Toxicity SARC Second Report: Acifluorfen ( PC Code: 114402)

FROM: Paul Chin Reregistration Branch I Health Effects Division ( 7509C)

TO: Pauline Wagner, Co Chair Mechanism of Toxicity Assessment Review Committee ( MTARC) Health Effects Division ( 7509C) and Karl Baetcke, Co Chair Mechanism of Toxicity Assessment Review Committee ( MTARC) Health Effects Division ( 7509C)

cc: Anna Lowit ( RRB2), Kit Farwell ( RRB1), Christina Scheltema ( SRRD)

The Mechanism of Toxicity Assessment Review Committee ( MTARC) reviewed the toxicological data supporting peroxisome proliferation as a proposed mode of action for the carcinogenic effects of acifluorfen in mice on April 17, 2003. The first report contains the conclusions from this meeting.

At the recent Cancer Assessment Review Committee ( CARC) meeting ( May 21, 2003), the CARC concluded that the increased levels of enzymes ( ALP and SGPT) seen at 40.5 mg/ kg/ day in the carcinogenicity study in mice ( CD 1) were considered equivocal because of large standard deviations. Therefore, the first MTARC report was revised to reflect this conclusion.

THIS DOCUMENT SUPERSEDES THE PREVIOUS MTARC REPORT DATED MAY 14, 2003 ( TXR No. 0050227).  2 Committee Members in Attendance Members who were present and gave electronic concurrence to this report were: Vicki Dellarco, Alberto Protzel, Anna Lowit, Ayaad Assaad, Karen Hamernik, Karl Baetcke, Pauline Wagner, Elizabeth Mendez, and John Doherty.

Also in attendance were: Whang Phang ( RRB1), Michael Metzger ( RRB1), Kit Farwell ( RRB1), Tawanda Spears ( SRRD), Brian Dementi ( TOX)

Data Evaluation / Report Preparation Byong Han Chin, Ph. D Toxicologist  3 I. Conclusion The Mechanism of Toxicity Assessment Review Committee ( MTARC) reviewed and debated the toxicological data supporting peroxisome proliferation as a proposed mode of action for the carcinogenic effects of acifluorfen in mice. The MTARC concluded that the currently available data are considered to be sufficient to support peroxisome proliferation as the mode of action of acifluorfen induced liver tumors in mice according to the criteria recommended by International Life Sciences Institute ( ILSI); these include:

1. Changes in liver morphology were observed in both rats and mice treated with acifluorfen. These effects include: dose dependent increase in relative liver weights, and increased incidence of cellular hypertrophy, and increased number of peroxisomes. 2. Evidence of cell proliferation as measured by increased relative liver weights and increased replicative DNA synthesis as measured by increased hepatocellular BrdU nuclear labeling in light microscopy.

3. Dose dependent increase in the levels of CN insensitive acyl ( palmitoyl) CoA oxidase activities involved in peroxisomal fatty acid metabolism.

Previously, the MTARC concluded that the peroxisome proliferation is the mode of action of lactofen in inducing liver tumors in rodents. Since acifluorfen is the major metabolite of lactofen in the rodents, acifluorfen is considered likely to contribute to the peroxisome proliferation induced by lactofen. Therefore, the data on lactofen provide some support for acifluorfen.

II. Background Information ACIFLUORFEN ( Sodium 5[ 2 chloro 4( trifluoromethyl) phenoxy] 2 nitrobenzoate) is the active ingredient of two herbicides formulations, Tackle and Blazer, which were originally manufactured by two separate companies. Acifluorfen is a contact herbicide used for selective pre and post emergence control of annual broad leaf weeds and some grasses in rice, peanut, and soybean production. Acifluorfen is also a major metabolite of another registered herbicide lactofen.

Although toxicological data are available on both acifluorfen products, the data provided on Blazer are incomplete, whereas, the data on Tackle are more current and complete. Therefore, discussions of the toxicology of acifluorfen are predominantly based on the data derived from the more recent studies with Tackle, and where appropriate the data on Blazer are also utilized. It should be noted that Tackle contains about 20% to 24% of acifluorfen as the active ingredient, whereas Blazer contains approximately 40% of acifluorfen.  4 O Cl NO2 COONa F3C In rats, acifluorfen was rapidly absorbed following oral administration and eliminated mainly in the urine ( 46 58%) and feces ( 21 41%). The major component present in urine was unchanged acifluorfen and the major component in feces was unchanged acifluorfen and an amine metabolite. No tissue accumulation was observed.

III. Chemical and Physical Properties of Acifluorfen Chemical Structure:

Common Synonyms: Blazer, Tackle Physical Properties: Melting point: > 212o F Water Solubility: > 25%

CAS No.: 62476 59 9 IV. Regulatory History The registrant ( BASF) submitted a petition ( MRID No. 45323500) requesting that risk assessment for acifluorfen be based on the MOE approach rather than using a Q 1* in human equivalents ( from K. Blundell, BASF to Ms. Christina Scheltema, Chemical Review Manager, SRRD, MRID No. 45323500 dated Feb. 2, 2001). The petition reviewed and summarized earlier data submissions which supported peroxisome proliferation as the mode of action of acifluorfen for induction of liver tumors. The current unit risk [ Q 1*] is 1.27 x 10 2 ( mg/ kg/ day) 1 ( memorandum from L. Brunsman to P. Chin, dated November 8, 2001).

The data supporting the proposed mode of action as presented by the registrants were considered at a preliminary meeting of the Mechanism of Toxicity Assessment Review Committee ( MTARC), HED on Aug. 23, 2001. The Committee evaluated the available data according to criteria recommended by the International Life Sciences Institute ( ILSI) workshop on peroxisome proliferation for determining whether or not liver tumors were induced by acifluorfen via a peroxisomal proliferation. The ILSI criteria are as follows:

1. Changes in liver morphology indicating hepatomegaly as measured by increased relative liver weights and an increased number of peroxisomes as measured by morphometric analysis.  5 2. Evidence of cell proliferation as measured by increased relative liver weights and increased replicative DNA synthesis as measured by increased hepatocellular BrdU nuclear labeling in light microscopy.

3. Increased levels of enzymes involved in peroxisomal fatty acid metabolism, especially CN insensitive acyl ( palmitoyl) CoA oxidase activities.

The MTARC concluded that the available data were insufficient to support the proposed mode of action of peroxisome proliferation for acifluorfen. BASF was informed of this decision ( e mail to R. Hawks from B. H. Chin, dated 9/ 12/ 01). Subsequently the registrant proceeded to develop the necessary data and submitted the following new mechanism studies with acifluorfen:

1) The induction of the number and size of hepatic peroxisomes in mice following 4 week dietary feeding with acifluorfen ( MRID 45693401),

2) S phase response study in the liver of mice following 3 days, 1 week, and 2 weeks feeding with acifluorfen ( MRID45803601)

3) Enzyme induction study in the liver of mice following 4 weeks feeding with acifluorfen ( MRID 45793901).

V. Evaluation of the Toxicology Data Base for Acifluorfen Subchronic Toxicity Studies with acifluorfen Available studies are adequate to satisfy subchronic testing requirements for acifluorfen. The subchronic feeding studies in rats and mice showed decrease in body weight and liver toxicity such as increased liver weight and increased incidence of cellular hypertrophy. There is no subchronic toxicity in dogs on acifluorfen. However, there was an acceptable chronic feeding toxicity study in dogs.

Chronic Toxicity and Carcinogenicity Studies with acifluorfen and Classification of Carcinogenic Potential The chronic feeding toxicity studies in rats, mice and dogs demonstrated that acifluorfen induced liver toxicity ( acidophilic cells in the liver and increased liver weight) and kidney toxicity ( nephritis/ pyelonephritis and increased kidney weight). Acifluorfen induces an increase in combined malignant and benign liver tumor incidence in two mouse carcinogenicity studies employing different strains of mice ( B6C3F1 and CR CD 1) [ HED Doc. No. 003410; 001099; 003963; 003409; 003556]. The data were evaluated by the HED Cancer Peer Review Committee ( HED Doc. No. 007698 dated March 17, 1988). Acifluorfen was classified as a Group B, probable human carcinogen, and the unit risk [ q* 1] was calculated to be 1.27 x 10 2 ( mg/ kg/ day) 1 ( memorandum from L. Brunsman to P. Chin, dated November 8, 2001). A two year bioassay in the F 344 rat administering Tackle ( approximately 20 24% acifluorfen) in the diet for 24 months did not show any treatment related increase in tumor incidence.  6 Mutagenicity The genetic toxicology studies indicate that acifluorfen was weakly mutagenic in Salmonella typhimurium TA100 and in Saccharomyces cerevisiae in the presence of S9 metabolic activation. However, in a repeat study, acifluorfen was negative in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 in the presence and absence of metabolic activation. Also, the test material was negative for gene mutations in Chinese hamster ovary ( CHO) cells and for clastogenic effects in vivo. In addition, acifluorfen was not mutagenic in DNA synthesis assay in primary rat hepatocytes and in in vivo dominant lethal assay in rats. The mutagenicity studies satisfy the pre 1991 mutagenicity guideline requirements. Summaries of the submitted acceptable mutagenicity studies are presented below ( Table 1).

Mechanism Studies with acifluorfen The relevant data concerning possible acifluorfen induced peroxisome proliferation are presented as follows:

A. Liver Toxicity ( Table 2)

Pertinent results from various guideline studies that are relevant to the proposed mechanism of action of acifluorfen are summarized in Table 2. There are several studies that show acifluorfen induced liver toxicity. The subchronic feeding toxicity studies in rats and mice, chronic feeding toxicity studies in rats and dogs, and carcinogenicity study in mice ( CD 1 and B6C3F1) showed that acifluorfen caused liver toxicity as characterized by increased absolute and relative liver weights. In addition, acifluorfen caused increased microscopic change in the liver in the chronic rat study at 125 mg/ kg/ day ( increased incidence of acidophilic cells) and in the chronic dog study at 112.5 mg/ kg/ day ( congestion, brown pigment, fatty vacuoles and inflammation). In the 90 day study in B6C3F1 mice, fatty infiltration of the liver was observed at 187.5 mg/ kg/ day or higher and increased incidence of histopathological changes in the liver ( hypertrophy, increased mitotic activity, and oval cell proliferation) and increased levels of enzymes ( ALP and SGPT) were seen at 375 mg/ kg/ day or higher. These levels were above the dose levels which induce peroxisome proliferation. It is noted that increased levels of enzymes ( ALP and SGPT) seen at 40.5 mg/ kg/ day in the carcinogenicity study in mice ( CD 1) were considered equivocal because of large standard deviations.

B. Peroxisome Proliferation ( Table 3)

A study designed to determine whether or not acifluorfen induces an increase in peroxisome proliferation is available and the executive summary of the study follows:

The effects of 4 week dietary administration of Blazer Technical ( Lot # 01501L300, purity 46% acifluorfen) on the induction of the number and size of hepatic peroxisomes in male and female B6C3F1 mice ( 5/ sex/ dose) was investigated ( MRID 45693401). The  7 administered concentrations were 0, 350, 1735, or 5210 ppm ( equivalent to 0, 92, 484, and 1346 mg/ kg/ day in males and 0, 139, 644, and 1939 mg/ kg/ day in females, respectively). Mean daily intakes of the a. i. were 42/ 64, 223/ 296 and 619/ 892 mg/ kg/ day, [ males/ females], respectively. Blazer Technical induced a slight to moderate increase in the number of peroxisomes within the centrilobular region of the high dose group of both sexes observable by light microscopy. No changes were found in male and female mice of lower dose groups. By electron microscopy, treatment with Blazer Technical induced a dose related increase in the number, size, and area of hepatic peroxisomes in mice treated with

350 ppm test material, thereby suggesting that Blazer Technical is a weak peroxisome proliferator. At 350 ppm, only slight increase of size 1 peroxisome ( up to 1.5 fold; p< 0.05) in males and females were observed.

At 1735 ppm, significant increase in number of peroxisomes ( 2 6 fold; p< 0.01) in both sexes were observed. In both sexes of mice, dose related significant increase ( p< 0.01) in total peroxisomal area was apparent ( 2.7 fold increases in males and 2.2 fold increases in females).

At 5210 ppm, significant increase in number of peroxisomes in males ( 3 23 fold; p< 0.01) and females ( 1.5 35 fold; p< 0.01) were observed. In both sexes of mice, dose related significant increase ( p< 0.01) in total peroxisomal area was apparent ( 7.2 fold increases in males and 8.3 fold increases in females).

By electron microscopy, the positive control diisononyl phthalate ( DINP) treatment for 4 weeks in mice significantly increased the size, number, and cytoplasmic area of peroxisomes in male mice treated with

500 ppm and female mice treated with

1500 ppm. Particularly increased were the number of microperoxisomes in mice treated with

4000 ppm DINP. There were also a dose related increase in cytoplasmic volume of male and female mice treated with

1500 ppm positive control ( MRID 45686501).

C. Evidence of Cell Proliferation ( Table 3)

A study designed to determine whether or not acifluorfen induces cell proliferation as measured by increased relative liver weights and increased replicative DNA synthesis as measured by increased hepatocellular BrdU nuclear labeling is available. The executive summary of the study follows:

In a DNA synthesis ( S phase response)/ cell proliferation study ( MRID 45803601), Blazer Technical ( 46.1% sodium acifluorfen in acetone) was administered to groups of 8 male and 8 female B6C3F1 mice at dietary concentrations of 0, 350, 1735 and 5210 ppm ( i. e.: 160, 800 and 2400 ppm of the active ingredient), mean daily intakes of the a. i. for males/ females of 40/ 54, 227/ 287 and 714/ 845 mg/ kg/ day, respectively, for 3 days, 1 week or 2 weeks. Food consumption and body weights were determined weekly. The animals were examined at least once a day; and additionally, comprehensive clinical examination was performed weekly. One week prior to necropsy, osmotic mini pumps containing bromodeoxyuridine ( BrdU) were implanted subcutaneously. Cell proliferation ( S phase response) and apoptosis were determined in the liver.  8 No animals died during the study and no clinical signs were observed. The test material had no effect on food or water consumption, and there were no consistent effects on male or female body weight.

Dose related increases in liver weights ( generally both absolute and relative) and findings of moderate or moderate to severe increases in panlobular hypertrophy of hepatocytes were seen in males and females exposed to 714/ 845 a. i. mg/ kg/ day, respectively, on all treatment schedules ( 3 day, 1 and 2 week). Liver hypertrophy was most pronounced in the males and peaked after 1 week of treatment. By 2 weeks, an increase in single cell necrosis and apoptotic cells was observed primarily in high dose males. This finding, suggesting cytotoxicity to the target organ, indicates that dosing was adequate to assess cell proliferation in the liver. The oral administration of Blazer Technical ( 46.1% acifluorfen sodium) to mice produced a dose dependent and significant induction of BrdU labeling in the liver, which is indicative of cell proliferation ( S phase response), in all dose groups. The most pronounced effect for each of these three parameters (

liver weight,

liver hypertrophy and

BrdU labeling) for both sexes was seen after 1 week of treatment.

This study is classified as acceptable ( non guideline). Although this study does not satisfy the requirement for any current FIFRA Test Guideline 84 2, the results may be used in a possible mode of action analysis of the test substance.

D. Evidence of Increased Enzymatic Activity ( Table 3)

A study designed to determine whether or not acifluorfen induces enzymes involved in peroxisomal fatty acid metabolism, especially CN insensitive acyl ( palmitoyl) CoA oxidase activities is available. The executive summary of the study follows:

In an enzyme induction study ( MRID 45793901), Blazer technical ( 46.1% acifluorfen Na a. i. in acetone) was administered to groups of 10 male and 10 female B6C3F1 mice at dietary concentrations of 0, 350, 1735 and 5210 ppm ( 160, 800 and 2400 ppm of active ingredient) for 4 weeks. Mean daily intakes of the a. i. were 36.9/ 54.6, 180/ 255 and 709/ 933 mg/ kg/ day, [ males/ females], respectively. Food consumption and body weights were determined weekly. Animals were examined once a day, and a comprehensive clinical examination carried out weekly. In the first 5 animals of each group, glutathione concentration ( GSH) in the liver was determined; in the second 5 animals, the amount of cyanide insensitive palmitoyl CoA oxidation ( PALCoA) in total protein was measured.

At the high dose, significant ( p  0.01) decreases in male body weights were recorded on days 14, 21 and 28; the greatest decrease in male body weights ( 9.2%) occurred on Day 28. Body weight gain for this group was also significantly ( p  0.01) reduced compared to control at the same time intervals. No clear adverse effects were found on female body weight. There was a significant ( p  0.01) and dose dependent increase in PALCoA, which is involved in peroxisomal fatty acid metabolism, ranging from a 58 to 576% increase for males and a 3 to 707% increase for females at 350 to 5210 ppm, respectively. Increased  9 PALCoA was accompanied by decreased GSH concentrations in high dose males ( 9%  ) and females ( 15%  ) ; the response was dose related for both sexes but only reached statistical significance in the high dose females. Based on these considerations, it was concluded that Blazer technical, containing 46.1% NA acifluorfen as the a. i., showed clear evidence of the induction of the peroxisomal enzyme system. Thus, the demonstration of peroxisomal enzyme system induction in the liver satisfies one of the necessary criteria to classify a nongenotoxic substance as a peroxisome proliferator.

The following special study also supports the findings of the new mechanism study described above. In this special study, hepatocytes isolated from male Sprague Dawley rats were exposed to acifluorfen or lactofen ( MRID No.: 45283902) to examine the induction of palmitoyl CoA oxidase activity following in vitro exposure. This study showed that both acifluorfen and lactofen displayed increased activity of palmitoyl CoA oxidase activity following in vitro exposure ( Table 3).

VI Data from Lactofen Studies The relevance of peroxisome proliferation ( PP) to hepatocarcinogenesis has been previously discussed for lactofen ( see HED Memorandum: Lactofen: Report of the Mechanism of Toxicity Assessment Review Committee from Robert F. Fricke to Christine Olinger, dated March 12, 2001).

A. Rationale for Using Lactofen Data 1. Lactofen is a diphenyl ether herbicide and the structure of lactofen is very similar to that of acifluorfen ( see below).

2. The metabolism study of lactofen in rats showed that acifluorfen is a major metabolite of lactofen ( Accession No. 071222). Seventy two hours after administration of lactofen to rats,

97% of the radiolabel was recovered in the excreta ( urine and feces). Urinary excretion comprised 39  56% of the dose while the fecal output totaled  43  67% of the dose. While the parent compound, lactofen, was the major component in the feces, the major metabolite in urine was acifluorfen which accounted for > 90% of the radioactivity recovered in this fraction.  10 C H 3 O O CH 3 O Cl F F F O O N +

O O O Cl F F F OH O N+ O O Figure 1: Structures of Lactofen and Acifluorfen Lactofen ( PPG 844)

Acifluorfen ( PPG 847 )

3. Following a single oral dose of radiolabeled lactofen at 50 mg/ kg to the SD rats and mice ( strain not identified), acifluorfen was the primary metabolite of lactofen in the plasma. The plasma level of acifluorfen at peak ranged 61 71% of the administered radioactivity [ Hawks, ( 2001). p22 of the BASF Report dated January 31, 2001 entitled Sodium Acifluorfen: Request for Reassessment of Current Cancer Classification Considering Peroxisome Proliferation   Associated Mode of Action].

B. The Lactofen Data in Supporting That the Peroxisome Proliferation is the Mode of Action of Lactofen The submitted lactofen data in supporting that peroxisome proliferation is the mode of action of lactofen are as follows:

1. The mutagenicity studies showed that lactofen is neither mutagenic nor genotoxic. A non guideline mutagenicity study showed equivocal ( probably negative) binding of lactofen to DNA.  11 2. Changes in liver morphology were observed in both rats and mice treated with lactofen in the diet for 8 and 7 weeks, respectively ( MRID No. 45283904). These effects include: dose dependent increase in relative liver weights and increased number of peroxisomes as measured by electron microscopic analysis. Further, in both rats and mice there was a dose dependent increase in nuclear enlargement, cytoplasmic eosinophilia, hypertrophy and peroxisomal staining. In addition, treatment with lactofen resulted in dose dependent increases ( particularly in female mice) in the activities of hepatic CN insensitive palmitoyl CoA oxidase and carnitine acetyl transferase.

3. Dose dependent increase in CN insensitive palmitoyl CoA oxidase was also observed in primary rat hepatocytes treated with lactofen ( MRID No. 45283902).

4. The doses at which carcinogenicity were observed [ mouse, LOAEL = 50 ppm ( 7.1 mg/ kg/ day); rat, LOAEL = 2000 ppm ( 76 mg/ kg/ day)] were consistently higher than the doses which caused peroxisome proliferation ( for details see HED Memorandum: Lactofen: Report of the Mechanism of Toxicity Assessment Review Committee from Robert F. Fricke to Christine Olinger, dated March 12, 2001).

The major metabolite of lactofen in the rodent is acifluorfen ( see Table 4. Comparative Metabolism of acifluorfen and lactofen in Rats). Since the MTARC concluded that the peroxisome proliferation is the mode of action of lactofen, peroxisome proliferation data generated using lactofen can be considered in evaluating the hypothesis that acifluorfen is a peroxisome proliferation.

VII. Other Modes of Action As stated previously, the weight of the evidence indicates that acifluorfen does not possess mutagenic activity. Currently, no other mode of action has been hypothesized for acifluorfen.

VIII. Structural Activity Relationships ( SAR)

As a member of the diphenyl ether chemical family, acifluorfen ( lactofen's major metabolite) is structurally related to four other chemicals, namely lactofen, nitrofen, oxyfluorfen, and fomesafen. Lactofen produces hepatocellular adenomas and carcinomas in mice and increases in liver neoplastic nodules and foci of cellular alteration ( possible precursor of tumors) in rats. Nitrofen produces hepatocellular carcinomas in mice and pancreatic carcinomas in rats, oxyfluorfen produces marginally positive liver tumors in mice but is negative in rats, and fomesafen produces hepatocellular adenomas and carcinomas in mice.

Acifluorfen contains the following basic structural features in common with other compounds causing peroxisome proliferation:

S a chlorinated benzene ring to which an ether linkage is attached,

S a terminal carboxyl group ( Eacho, 1996), and S a lipophillic backbone ( Kozuka, 1991).  12 VII. SUMMARY Based on the available toxicity data, there is evidence to support that acifluorfen is a non genotoxic hepatocarcinogen. Tables 5 and 7 show " Summary of Peroxisomal Effects and Liver Tumor Induction in Male and Female Mice Administered Acifluorfen". Tables 6 and 8 show " Summary of Liver Toxicity and Tumor Induction in Male and Female Mice Administered Acifluorfen". Table 9 provides quantitative evaluation of peroxisomes and cytoplasmic volume (%) in male and female mice fed acifluorfen ( Blazer Technical) or positive control ( DINP) for 4 weeks. These data ( Tables 5 9) provide supporting evidence of peroxisome proliferation as a mode of action for liver tumors induction by acifluorfen according to the criteria recommended by ILSI; these include:

1. Changes in liver morphology were observed in both rats and mice treated with acifluorfen. These effects include: dose dependent increase in relative liver weights, and increased incidence of cellular hypertrophy, and increased number of peroxisomes as measured by electron microscopic analysis.

2. Evidence of cell proliferation as measured by increased relative liver weights and increased replicative DNA synthesis as measured by increased hepatocellular BrdU nuclear labeling in light microscopy.

3. Dosed dependent increase in the levels of enzymes involved in peroxisomal fatty acid metabolism, especially CN insensitive acyl ( palmitoyl) CoA oxidase activities.

4. Previously, the MTARC concluded that the peroxisome proliferation is the mode of action of lactofen in inducing liver tumors in rodents. Since acifluorfen is the major metabolite of lactofen in the rodents, it is probable that acifluorfen contributes to the peroxisome proliferation and liver tumors induced by lactofen. Therefore, the mode of action data on lactofen provide support for acifluorfen.  13 VIII. References 1. Eacho, P. I., Foxworthy, P. S., Lawrence, J. W., Herron, D. K., and Noonan, D. J. ( 1996) Common structural requirements for peroxisome proliferation by tetrazole and carboxylic acidcontaining compounds. Ann. NY Acad. Sci. 804: 387 402.

2. Hawks, R. ( 2001). Sodium Acifluorfen: Request for reassessment of current cancer classification considering peroxisome proliferation associated mode of action. BASF Registration Doc. No. 2001/ 5000878. BASF Corp. January 31, 2001. MRID No. 45323500.

3. IARC Technical Report No. 24: Peroxisome proliferation and its role in carcinogenesis. December, 1994.

4. Kozuka, H., Yamada, J., Horie, S, Watanabe, T., Suga, T. and Ikeda, T. ( 1991) Characteristics of induction of peroxisomal fatty acid oxidation related enzymes in rat liver by drugs. Biochem. Pharm. 41( 4): 617 623.

5. Lactofen: Report of the Mechanism of Toxicity Assessment Review Committee from Robert F. Fricke to Christine Olinger, dated March 12, 2001.

6. Reevaluation of Classification of Carcinogenicity of Acifluorfen Following Science Advisory Panel ( SAP) Review of Data. The HED Cancer Peer Review Committee ( HED Doc. No. 007698 dated March 17, 1988).

7. Goldenthal, E. I.; Jessup, D. C.; Geil, R. G.; et al. ( 1979) Lifetime Dietary Feeding Study in Mice: 285 013a. ( Unpublished study received Mar 29, 1979 under 707 149; prepared by International Research and Development Corp., submitted by Rohm & Haas Co., Philadelphia, Pa.; CDL: 098024 A; 098025). MRID 00082897.

8. Barnett, J.; Jenkins, L.; Parent, R. ( 1983) Evaluation of the Potential Oncogenic and Toxicological Effects of Long term Dietary Administration of Tackle to Fischer 344 Rats: GSRI Project No. 413 985 41. Final rept. ( Unpublished study received May 16, 1983 under 359 708; prepared by Gulf South Research Institute, submitted by Rhone Poulenc, Inc., Monmouth Junction, NJ; CDL: 250289 A; 250290; 250291). MRID 00128353.  14

Table 1. Genotoxicity/ Mutagenicity Profile of Acifluorfen ASSAY TYPE RESULT MRID Ames assay B standard plate assay ( Blazer, 42.8%) Gene mutation " Weakly" Positive in TA 100 only 41480101 Ames assay B standard plate and standard plate with preincubation using manufactoring use product ( 46%) Gene mutation Negative in TA 100 45393902 Ames assay B standard plate assay using highly pure material ( 99.5%) Gene mutation Negative 45393901 Ames assay B standard plate assay and standard plate with preincubation both using end use product ( 25.5%) Gene mutation Negative both with and without preincubation 45323501 Forward gene mutation in CHO cells Gene mutation Negative 41480103 Forward mutation in TK +/ locus in mouse lymphoma cells Gene mutation Negative 00122739 Drosophila melanogaster ( Tackle 2S)

White ivory mutation Sex linked recessive lethal Y chromosome loss Dominant lethal mutations Bithorax test Gene mutation Gene mutation Gene mutation Chromosome Aberrations Chromosome Aberrations Negative Negative Positive Positive Negative 00122737 In vivo rat cytogenetic assay Chromosome Aberrations Negative 00122741 Dominant lethal assay in rats Chromosome Aberrations Negative 00122738 In vitro unscheduled DNA synthesis Other mechanisms Negative 00122742 Saccharomyces cerevisiae D5 mitotic recombination ( Tackle 2S, 29.7%) Other mechanisms " Weak" positive 00148272 TOTAL 11 negative 4 positive  15

Table 2. Acifluorfen Toxicity Profile ( Appendix 1 presents the Executive Summaries for critical studies)

STUDY TYPE   DOSE LEVELS NOAEL/

LOAEL ( mg/ kg/ day) Liver weight Liver enzymes Histopathology Chronic/ Carcinogenicity  Rat Fischer 344 ( 1983) 0, 25,

150, 500, 2500, or 5000 ppm. ( 0, 1.25, 7.50, 25.0, 125,

or 250 mg/ kg/ day based on 1 ppm= 0.05 mg/ kg/ day)

TEST material = 19.2 25.6% a. i.

( MRID No. 00128353; Accession No's. 071315 through 071317 and 250289 through 250792) 25/ 125 increased absolute and relative liver weights equivocal increased level of ALP at 250 mg/ kg/ day increased incidence of acidophilic cells in the liver No treatment related increase in tumors Carcinogenicity in Mice B6C3F1 ( 1982). 0, 625, 1250,

or 2500 ppm ( males: 0, 119, 259, 655 mg/ kg/ day;

females: 0, 143, 313, 711 mg/ kg/ day) TEST material =

20.4 23.2% a. i.

( MRID No. 00122732; Accession No's. 071312, 071313,

071314, 250463, and 250464) < 119 ( LDT) increased absolute and relative liver weights Not observed at LDT p< 0.05 0.01 liver adenomas;

liver carcinomas; combined liver adenomas & carcinomas p< 0.01 trend for adenomas (

 ) ; carcinomas (

) ;

adenomas & carcinomas combined (

 )

Carcinogenicity in Mice CD 1 ( 1979). 0, 7.5, 45, or 270 ppm ( 1.125, 6.75, or 40.5 mg/ kg/ day based on 1 ppm =

0.15 mg/ kg/ day) for 24 months. TEST material = 39.4

40.5% a. i.

( MRID No. 00082897) 6.75/ 40.5 increased absolute and relative liver weights equivocal increased levels of ALP and SGPT. p< 0.05 combined liver adenomas & carcinomas ( 270 ppm

)

Chronic Feeding Study in Dogs ( 1983). Tackle " 2S"

( Acifluorfen, purity was unspecified). 0, 20, 300, or 4500 ppm ( 0, 0.5, 7.5 or 112.5 mg/ kg/ day based on 1 ppm = 0.025 mg/ kg/ day) for 2 years ( MRID No. 00131162; Accession No's. 251297 and 251298) 7.5/ 112.5 increased absolute and relative liver weights increased level of LDH increased incidence of microscopic changes in the liver ( congestion, brown pigment, fatty vacuoles and inflammation). STUDY TYPE   DOSE LEVELS NOAEL/

LOAEL ( mg/ kg/ day) Liver weight Liver enzymes Histopathology  16

Subchronic feeding study in rats Fischer 344 ( 1982). 0,

20, 80, 320, 1250, 2500 or 5000 ppm ( 0, 2, 8, 32, 125,

250, or 500 mg/ kg/ day based on 1 ppm = 0.1 mg/ kg/ day)

TEST material = 20.4 23.6% a. i.

( MRID No. 00122730; Accession No. 071308) 32/ 125 increases in liver weights at 250 or higher increased levels of SGPT and ALP increased incidence of hypertrophy of liver ( including increased cellular hypertrophy,

mitotic activity, individual cell death, and proliferation of oval or bile duct cells)

Subchronic feeding study in mice B6C3F1 ( 1982) 0, 20,

80, 320, 1250, 2500 or 5000 ppm ( 0, 3, 12, 48, 187.5,

375, or 750 mg/ kg/ day based on 1 ppm = 0.15 mg/ kg/ day) for 3 months TEST material = 20.4 23.2% a. i.

( MRID No. 00252826; Accession No. 071308) 48/ 187.5 At 375 mg/ kg/ day as test material intake:

Increases in absolute and relative liver weights At 375 mg/ kg/ day and above: Increased levels of SGPT and ALP At 187.5 mg/ kg/ day:

histopathologic changes ( fatty infiltration) of the liver At 375 mg/ kg/ day and above:

histopathological changes in the liver ( hypertrophy, increased mitotic activity, oval cell proliferation)  17

Table 3. Summary of Mechanistic Studies with Acifluorfen STUDY TYPE B DOSE LEVELS Liver weight Liver enzymes Electron microscopy Induction of the number and size of hepatic peroxisomes in mice following 4 week dietary feeding ( MRID 45693401).

0, 350, 1735, or 5210 ppm Blazer ( 46% a. i.), test material ( equivalent to 0, 92, 484, and 1346 mg/ kg/ day in males and 0, 139, 644, and 1939 mg/ kg/ day in females)

mean daily intakes of the a. i. were 42/ 64, 223/ 296 and 619/ 892 mg/ kg, [ males/ females] NA NA Induced dose related increase in the number, size,

and area of hepatic peroxisomes in mice treated with

350 ppm Dose related increase in total peroxisomal area in high dose groups ( 7.2 fold increases in males and 8.3 fold increases in females).

S phase response study in the liver of mice following 3 days, 1 week, and 2 weeks feeding ( MRID45803601)

0, 350, 1735 and 5210 ppm Blazer ( 46 % a. i.) ( i. e.:

160, 800 and 2400 ppm of the active ingredient),

mean daily intakes of a. i. for males/ females of 40/ 54, 227/ 287 and 714/ 845 mg/ kg/ day Induced doserelated increases in absolute and relative liver weights NA At high dose, Induced a doserelated increases in panlobular hypertrophy of hepatocytes on all treatment schedules.

Liver hypertrophy was most pronounced in the males and peaked after 1 week of treatment.

By 2 weeks, an increase in single cell necrosis and apoptotic cells was observed primarily in high dose males.

Inducted BrdU labeling in the liver, which is indicative of cell proliferation ( S phase response). STUDY TYPE B DOSE LEVELS Liver weight Liver enzymes Electron microscopy  18

Enzyme induction study in the liver of mice following 4 weeks feeding ( MRID 45793901).

0, 350, 1735 and 5210 ppm Blazer ( 46 % a. i.) ( 160,

800 and 2400 ppm of active ingredient) for 4 weeks.

Mean daily intakes of a. i. were 36.9/ 54.6, 180/ 255 and 709/ 933 mg/ kg/ d, [ males/ females] NA Induced dosedependent increase in cyanideinsensitive palmitoyl

CoAoxidase 5  7 fold in high dose groups ( males and females)

Males: 158, 458,

and 676% increase at 37, 180, and 709 mg/ kg/ day Females: 3, 316,

and 807% increase at 55, 255, and 933 mg/ kg/ day NA Measurement of Peroxisome Proliferation in Primary Rat Hepatocytes Induced by Lactofen and Five of its Metabolites including acifluorfen ( 45283902)

0.003, 0.01, 0.03, and 0.1 mM NA Acifluorfen or lactofen induced CN insensitive palmitoyl CoA oxidase activities at 0.01 mM and above. EM analysis did not indicate an increased peroxisome number.  19

Table 4. Comparative Metabolism of acifluorfen and lactofen in Rats Dose ( mg/ kg) Sex Cumulative % Radioactivity Excreted Urine Feces 24 hrs 48 hrs 72 hrs 96 hrs 24 hrs 48 hrs 72 hrs 96 hrs Acifluorfen ( 1) 116 Males 48 41 117 Females 60 23 Lactofen ( 2) 125 Males 29 36 44 34 62 67 125 Females 19 53 56 18 35 43 Urinary and Fecal Metabolites Major component in Urine % of Total Urinary radioactivity found (% of administered dose) Major component in feces % of Total Fecal radioactivity found (% of administered dose)

Acifluorfen ( 1) 116/ 117 Males/ Females Acifluorfen 93 ( 50) Acifluorfen amine Acifluorfen 60 80 ( 19 26)

13 ( 4)

Lactofen ( 2) 125/ 125 Males/ Females Acifluorfen 91 ( 46) Lactofen Acifluorfen amine Acifluorfen 30 37 ( 17 20)

7 ( 4)

6 ( 3)

( 1) Excerpted from MRID 00122746; Accession No. 071321. The elimination half life of acifluorfen was 3.7 hours in females versus 8.8 hours in males.

( 2) Excerpted from Accession No. 071222; HED Doc. No. 014148  20

Table 5. Summary of Peroxisomal Effects and Liver Tumor Induction in Male Mice Administered Acifluorfen Dose ( mg/ kg/ day)

as active ingredient Mean Number of Peroxisome according to size classification ( relative to controls, %)

MRID 45693401 ( a) Induction of Peroxisomal Enzyme Activities;

Palmitoyl CoA oxidase MRID 45793901 ( b) Cell proliferation;

BrdU labeling in the liver ( S phase response)

MRID 45803601 ( c) Tumor incidence (% incidence)

18 month carcinogenicity study in mice MRID 00122732 ( d)

( Note 2)

1 (< 0.1

m2) 2 (< 0.3

m2) 3 (< 0.5

m2) Total area of peroxisomes ( note 1) Adenomas Carcinomas Adenomas/ Carcinomas Combined 0 7.8 ± 1.5 ( SD) 8.0 ± 2.0 0.5 ± 0.4 1.25 ± 0.18 5.24 ± 0.5 1.01 ± 0.3 8/ 58 ( 14 %) 1/ 48 ( 2 %) 9/ 58 ( 16 %)

37 42 11.8*

( 51%)

± 4.1 9.6 ( 20%)

± 1.7 0.3 ± 0.2 1.49 ( 19%)

± 0.29 8.29**

( 58%)

± 0.57 4.07 **( 304%)

± 1.86 NT NT NT 119 NT NT NT NT NT NT 18/ 60 ( 30 %) * 3/ 50 ( 6 %) 21/ 60 ( 35 %) *

180 227 15.4**

( 97%)

± 3.1 18.7**

( 134%)

± 2.3 2.9**

( 480%)

± 1.6 3.43**

( 174%)

± 0.63 25.29**

( 383%)

± 2.93 14.09 **( 1300%)

± 2.69 NT NT NT 259 NT NT NT NT NT NT 12/ 56 ( 21 %) 4/ 46 ( 9 %) 16/ 56 ( 29 %)

619 714 22.3**

( 185%)

± 9.4 35.7**

( 346%)

± 10.1 11.4**

( 2180%)

± 3.4 9.03**

( 622%)

± 2.54 35.41**

( 576%)

± 2.49 20.61**( 1947%)

± 3.57 25/ 59 ( 42 %) ** 15/ 44 ( 34 %) ** 40/ 59 ( 68 %)

**

NT: Not tested * Significantly different than control ( p< 0.05) ** Significantly different than control ( p< 0.01)

Note 1: The area occupied by peroxisomes was expressed in relation to cytoplasmic region as %. Size classes 1 5 (< 0.1  > 0.75  m2).

Note 2: Significance of pairwise comparison with control ( Fisher's Exact Test) denoted at Dose level. Tumor bearing animals/ animal at risk ( i. e., the animals,

which died prior to the week of the first tumor occurrence for each tumor type, are removed from the animals at risk).

a) 4 week treatment at 42, 223, and 619 mg/ kg/ day b) 4 week treatment at 37, 180, and 709 mg/ kg/ day c) 1 week treatment at 40, 227, and 714 mg/ kg/ day d) 18 month study. Overall mean doses were 119, 259, and 655 mg/ kg/ day. SD: Standard deviation  21

Table 6. Summary of Liver Toxicity and Tumor Induction in Male Mice Administered Acifluorfen Dose ( mg/ kg/ day)

as active ingredient Subchronic study ( a)

( MRID 00252826) Cell Proliferation Study ( b)

( MRID 45803601) 18 month carcinogenicity study in mice ( MRID 00122732)

Fatty infiltration of liver hypertrop hy, mitotic activity and increased levels of SGPT and ALP Hypert rophy Single cell necrosis and apoptotic cells Body weight, g (% of controls) Absolute Liver weight, g (% of controls) Relative Liver weight (% of controls) Body weight,

% of controls Liver weight, g (% of controls) Adenomas/ Carcinomas Combined 0 30.6 1.51 4.94 2.03 9/ 58 ( 16 %)

40 48 NF NF NF NF 30.5 ( 99.7%) 1.63 ( 108%)** 5.34 ( 108)** NT NT NT 119 NT NT NT NT NT NT NT 90** 2.41 ( 119%) 21/ 60 ( 35 %) *

188 +++ ( d) NF NT NT NT NT NT NT NT NT 227 NT NT NF NF 31.3 ( 102%) 2.13 ( 141%)** 6.80 ( 137%)

** NT NT NT 259 NT NT NT NT NT NT NT 87** 2.95 **

( 145%) 16/ 56 ( 29 %)

375 +++ +++ NT NT NT NT NT NT NT NT 655 750 +++ +++ +++ +++ 27.3 ( 89%) ** 1.90 ( 125%)** 6.94 ( 140%)

** 75** 3.75 **

( 185%) 40/ 59 ( 68 %) **

NT: Not tested NF: Not found * Significantly different than control ( p< 0.05) ** Significantly different than control ( p< 0.01)

a) Treated for 90 days at 3, 12, 48, 188, 375, and 750 mg/ kg/ day.  22

b) Treated for 2 weeks at 40, 227, and 714 mg/ kg/ day c) 18 month study. Overall mean doses were 119, 259, and 655 mg/ kg/ day. d) +++ means positive responses.  23

Table 7. Summary of Peroxisomal Effects and Liver Tumor Induction in Female Mice Administered Acifluorfen Dose ( mg/ kg/ day)

as active ingredient Mean Number of Peroxisome according to size classification ( relative to controls, %)

MRID 45693401 ( a) Induction of Peroxisomal Enzyme Activities;

Palmitoyl CoA oxidase MRID 45793901 ( b) Cell proliferation;

BrdU labeling in the liver ( S phase response)

MRID 45803601 ( c) Tumor incidence (% incidence)

18 month carcinogenicity study in mice MRID 00122732 ( d)

( Note 2)

1 (< 0.1

m2) 2 (< 0.3

m2) 3 (< 0.5

m2) Total area of peroxisomes ( note 1) Adenomas Carcinomas Adenomas/ Carcinomas Combined 0 9.5 ± 2.8 ( SD) 8.2 ± 0.7 0.4 ± 0.3 1.27 ± 0.13 5.65 ± 0.94 1.02 ± 0.24 1/ 55 ( 1 %) 0/ 45 ( 0 %) 1/ 55 ( 2 %)

54 55 64 13.2*

( 39%)

± 1.4 7.5 ± 0.8 0.2 ± 0.2 1.25 ± 0.18 5.81 (+ 3%)

± 0.54 1.31* ( 28%)

± 0.31 NT NT NT 143 NT NT NT NT NT NT 5 / 59 ( 5 %) 1/ 47 ( 2 %) 6/ 59 ( 10 %)

255 313 12.1 ( 27%)

± 2.1 15.9**

( 94%)

± 1.5 2.2**

( 450% )

± 1.0 2.81**

( 121%)

± 0.37 17.84**

(+ 216%)

± 1.79 3.68** ( 259%)

± 0.70 4/ 57 ( 4 %) 1/ 44 ( 2 %) 5/ 57 ( 9 %)

711 NT NT NT NT NT NT 19/ 58 ( 19 %) ** 5/ 46 ( 11 %) * 24/ 58 ( 41 %) **

845 933 14.6 ( 54%)

± 5.9 35.7**

( 335%)

± 11.4 14.0**

( 3400%)

± 3.9 10.6**

( 735% )

± 2.95 45.57**

(+ 707%)

± 3.65 6.19** ( 505%)

± 1.37 NT NT NT NT: Not tested * Significantly different than control ( p< 0.05) ** Significantly different than control ( p< 0.01) SD: Standard deviation Note 1: The area occupied by peroxisomes was expressed in relation to cytoplasmic region as %. Size classes 1 5 (< 0.1  > 0.75

m2).

Note 2: Significance of pairwise comparison with control ( Fisher's Exact Test) denoted at Dose level. Tumor bearing animals/ animal at risk ( i. e., the animals, which died prior to the week of the first tumor occurrence for each tumor type, are removed from the animals at risk).

a) 4 week treatment at 64, 296, and 892 mg/ kg/ day. b) 4 week treatment at 55, 255, and 933 mg/ kg/ day c) 1 week treatment at 54, 287, and 845 mg/ kg/ day d) 18 month study. Overall mean doses were143, 313, and 711 mg/ kg/ day.  24

Table 8. Summary of Liver Toxicity and Tumor Induction in Female Mice Administered Acifluorfen Dose ( mg/ kg/ d)

as active ingredient Subchronic study ( a)

MRID 00252826 Cell Proliferation Study ( b)

( MRID 45803601) 18 month carcinogenicity study in mice [ c]

( MRID 00122732)

Fatty infiltration of liver hypertrophy,

mitotic activity and increased levels of SGPT and ALP Hypertroph y Single cell necrosis and apoptotic cells Body weight, g (% of controls) Absolute Liver weight,

g (% of controls) Relative Liver weight (% of controls) Body weight,

% of controls Liver weight, g (% of controls) Adenomas/ Carcinomas Combined 0 25.6 1.3 5.07 1.70 1/ 55 ( 2 %)

48 54 NF NF NF NF 25.6 1.31 5.14 ( 101%) NT NT NT 143 NT NT NT NT NT NT NT 89** 1.59 ( 96%) 6/ 59 ( 10 %)

188 +++( d) NF NT NT NT NT NT NT NT NT 287 313 NT NT NF NF 25.5 1.62 ( 125%)

** 6.35 ( 125%)** 78** 1.90 ( 112%)* 5/ 57 ( 9 %)

375 +++ +++ NT NT NT NT NT NT NT NT 711 845 +++ +++ +++ NF 24.8 ( 97%) 2.19 ( 168%)

** 8.81 ( 174%)

** 66** 2.32 ( 136%)

** 24/ 58 ( 41 %) **

NT: Not tested NF: Not found * Significantly different than control ( p< 0.05) ** Significantly different than control ( p< 0.01)

a) Treated for 90 days at 3, 12, 48, 188, 375, and 750 mg/ kg/ day.

b) Treated for 2 weeks at 54, 287, and 845 mg/ kg/ day c) 18 month study. Overall mean doses were143, 313, and 711 mg/ kg/ day.

d) +++ means positive responses.  25 TABLE 9. Quantitative evaluation of peroxisomes and cytoplasmic volume (%) in male and female mice fed Blazer Technical ( acifluorfen) or DINP ( positive control) for 4 weeks.

Test Material Diet conc. ( ppm) Size Classification ( males) Size Classification ( females)

1 2 3 4 5 Total Area of peroxi somes ( in %) 1 2 3 4 5 Total Area of peroxi somes ( in %)

Blazer Technicala 0 7.8 8.0 0.5 0.0 0.0 1.25 9.5 8.2 0.4 0.0 0.0 1.27 350 11.8* 9.6 0.3 0.1 0.0 1.49 13.2* 7.5 0.21 0.0 0.0 1.25 1735 15.4** 18.7** 2.9** 0.2* 0.0 3.43** 12.1 15.9** 2.2** 0.2 0.0 2.81**

5210 22.3** 35.7** 11.4** 2.8** 0.3** 9.03** 14.6 35.7** 14.0** 4.3** 1.0* 10.6**

DINPb 0 12.1 10.7 1.0 0.1 0.1 1.93 24.6 12.1 1.4 0.1 0.0 2.48 500 18.2* 11.0 1.3 0.0 0.0 2.16 22.3 9.3 0.5 0.0 0.0 1.88 1500 55.0** 15.5 0.8 0.1 0.0 3.56** 32.4 19.9** 1.2 0.0 0.0 3.63*

4000 49.6** 47.3** 10.9** 1.1** 0.1 10.6** 31.3 37.2** 11.1** 2.1** 0.1 9.52**

8000 18.3** 35.5** 27.9** 13.9** 2.1** 18.7** 26.4 35.5** 18.6** 9.7** 1.8 14.8**

aData from pages 28 29 MRID 45693401 bData from page 29 of MRID 45686501 * p

0.05; ** p

0.01  26 APPENDIX I Supporting Executive Summaries Subchronic toxicity in rats In a 90 day feeding study ( MRID No. 00122730; Accession No. 071308), Tackle ( 20.4 23.6% a. i.) was administered to Fischer 344 rats ( 30/ sex/ dose) in the diet at levels of 0, 20, 80, 320, 1250, 2500 or 5000 ppm ( 0, 2, 8, 32, 125, 250 or 500 mg/ kg/ day based on a conversion factor of 1 ppm = 0.1 mg/ kg/ day) for 3 months. Body weights for 2500 and 5000 ppm males and 5000 ppm females were decreased ( 92.3 95.5%, 65.3% 71.2% and 83.3 90.6% of the controls, respectively). Food consumption for the 5000 ppm males and females was decreased throughout most of the study period. At 2500 ppm or above in one or both sexes, there were significant ( p< 0.05) changes in hematology parameters ( erythrocyte counts, hematocrit, and hemoglobin concentration), clinical chemistry values ( serum electrolytes, calcium, phosphorus, glutamic pyruvic transaminase and alkaline phosphatase activities, BUN, creatinine, serum protein, albumin and globulin concentrations) and urinalysis parameters ( nitrate and urobilinogen content). Liver and kidney weights ( both absolute and relative) were increased. Histopathological changes were seen in the liver of 2500 ppm or above males and females ( including increased cellular hypertrophy, mitotic activity, individual cell death, and proliferation of oval or bile duct cells).

In the 1250 ppm group ( in one or both sexes), there were decreases in hematology parameters ( erythrocyte counts and hematocrit values), increase in absolute and relative liver weights ( 20 21% and 22 74%, respectively), increase in absolute and relative kidney weights ( 11 13% and 10 12%, respectively), and increased incidence of hypertrophy of liver cells when compared to the controls.

No significant treatment related effects were seen in males or females of 320 ppm or below. The LOAEL for subchronic toxicity is 1250 ppm ( 125 mg/ kg/ day) based on decreases in hematology parameters, increases in liver and kidney weights, and increased incidence of hypertrophy of liver cells when compared to the controls. The NOAEL for systemic toxicity is 320 ppm ( 32 mg/ kg/ day).

NOTE: In the original DER [ TXR No. 003409 ( same as TXR No. 003556)], this study was classified as supplementary. The registrant was requested to submit the following: a) Individual animal histopathology on the animals of the 20 2500 ppm groups; b) An explanation of why in the " author's report the least frequent clinical observation was " loss of hair" while the submitted daily record of clinical signs did not mention this event [ pages 98 102 of the report].  27 In the Agency's response to registrant's comment on previous review, this study was classified as supplementary ( TXR No. 003963). The explanation of regarding " loss of hair" was satisfactory but the individual animal histopathology on the animals of the 20 2500 ppm groups was not submitted. This study is classified as Unacceptable/ guideline but upgradable. The data in this study was used to set the doses in the rat chronic/ carcinogenicity study.

Subchronic toxicity in mice In a 90 day feeding study ( MRID No. 00252826; Accession No. 071308), Tackle ( 20.4 23.2% a. i.) was administered to B6C3F1 mice ( 30/ sex/ dose) in the diet at levels of 0, 20, 80, 320, 1250 or 2500 ppm ( 0, 3, 12, 48, 187.5 or 375mg/ kg/ day based on a conversion factor of 1 ppm = 0.15 mg/ kg/ day) for 3 months. Changes in mean body weights, hematology ( total white blood cell numbers, MCV, reticulocyte counts), clinical chemistry ( SGPT, alkaline phosphatase, serum glucose), liver weights ( absolute and relative), and histopathological changes in the liver ( hypertrophy, increased mitotic activity, individual cell death and focal necrosis) were noted in males and females at the 2500 and 5000 ppm doses at 30 and 90 days. Fatty infiltration of the liver was observed in males and females at the 1250, 2500 and 5000 ppm doses at 30 days and at the 1250 and 2500 doses at 90 days.

The NOAEL for systemic toxicity is 320 ppm ( 48 mg/ kg/ day) and the LOAEL is 1250 ppm ( 187.5 mg/ kg/ day) based on histopathologic changes ( fatty infiltration) of the liver. This study is classified as unacceptable/ guideline but upgradable. The data in this study were used to select the doses in the mouse chronic/ carcinogenicity study.

Chronic toxicity in dogs In a chronic toxicity study ( MRID No. 00131162; Accession No's. 251297 and 251298), Tackle " 2S" ( Acifluorfen, sodium salt; purity was unspecified) was administered to Beagle dogs ( 8/ sex/ dose) in the diet at levels of 0, 20, 300 or 4500 ppm ( 0, 0.5, 7.5 or 112.5 mg/ kg/ day based on a conversion factor of 1 ppm = 0.025 mg/ kg/ day) for 2 years.

Body weights were lower than respective controls in males ( 8 to  20%) and females ( 9 to  10%) at 4500 ppm ( high dose) throughout the study ( statistical analysis was not performed). In addition, increases in liver and kidney weights ( both absolute and relative) were seen in high dose males and females. Additionally, in both sexes at high dose, red blood cell counts, hemoglobin, hematocrit and cholesterol values were significantly lower and leukocyte counts and urinary volume were significantly higher than those of the controls. In males at high dose, serum level of creatinine was lower than that of the controls. Platelet counts, lactate dehydrogenase activity and specific gravity of urine were higher than respective controls. In females at high dose, serum levels of calcium and albumin were lower when compared to the controls. Histologically, there were increased  28 incidence of microscopic changes in the liver ( congestion, brown pigment, fatty vacuoles and inflammation) when compared to the controls.

The LOAEL for systemic toxicity is 4500 ppm ( 112.5 mg/ kg/ day) based on decreased body weight gain, increased absolute and relative liver and kidney weights, changes in hematology, biochemistry, and urinalysis parameters and increased incidence of microscopic changes in the liver ( congestion, brown pigment, fatty vacuoles and inflammation). The NOAEL for systemic toxicity is 300 ppm ( 7.5 mg/ kg/ day).

This chronic feeding study in dogs is classified as Unacceptable/ guideline and does not satisfies the guideline data requirement for a chronic toxicity study ( 83 1) in dogs. However, it can be upgraded. Reasons for this classification are the purity of the test substance was not adequately identified in the report and stability of the test substance in dog chow was not reported. However, a new study is not required because when this study and the data of another chronic feeding study in dog ( MRID No. 00107484) with Blazer are analyzed together, they provide a reasonable understanding of the chronic toxicity of acifluorfen in dogs. Another chronic feeding study in dog ( MRID No. 00107484) with Blazer is an old study ( reported in 1978) which was classified as core guideline data, however, the DER for this study was not available. In the old study, there were changes in hematological and biochemical parameters related to the effects in the liver of the treated dogs at high dose ( 1800 to 5400 ppm) when compared to the controls. Histopathologically, treatment related alterations were observed in the liver, kidney, gall bladder and eyes when compared to the controls. The NOAEL for systemic toxicity was 50 ppm and LOAEL was 300 ppm ( mid dose) based on a coagulation effects when compared to the controls ( HED Doc. No. 001099; extracted from the earlier review of A. Arce dated May 2, 1979).

Chronic toxicity/ carcinogenicity in mice [ feeding]

( 1) In a 24 month carcinogenicity study ( MRID No. 00082897), Blazer ( 39.4 40.5% a. i.) was administered to CR CD 1 mice ( 80/ sex/ dose) in the diet at levels of 0, 7.5, 45 or 270 ppm for 24 months ( 0, 1.125, 6.75 or 40.5 mg/ kg/ day based on a conversion factor of 1 ppm = 0.15 mg/ kg/ day). The highest dose level was initially administered to mice at a dose of 1.25 ppm on study weeks 1 to 16 before being increased to 270 ppm. Blazer produced a statistically significant ( p< 0.05) increase in the total number of liver tumors ( primarily adenomas) in high dose ( 270 ppm) female mice. No significant increase in liver tumors occurred in male mice.

In high dose males, there was a dose related increase in absolute and relative liver weights and relative kidney weights. In addition, there was dose related elevation of alkaline phosphatase and serum glutamic pyruvic transaminase activities in mid and high dose male mice. However, due to the variability of the standard deviation for these parameters, statistical analysis was not performed.  29 The NOAEL for systemic toxicity is 45 ppm ( 6.75 mg/ kg/ day) and the LOAEL is 270 ppm ( 40.5 mg/ kg/ day) based on increased absolute and relative liver weights, and increased relative kidney weights. It is noted that increased levels of enzymes ( ALP and SGPT) seen at 40.5 mg/ kg/ day in this study were considered equivocal because of large standard deviations.

This study by itself does not satisfy the guideline requirement for a carcinogenicity study ( 83 2b) in mice. The deficiencies of the study report are as follows: resolution of histopathology questions; explanation of why the 270 ppm diet was analyzed only once; provide stability of the compound in feed data; explanation of Table 4 ( Food Consumption). However, the requirement for carcinogenicity study for mice is satisfied when considered together with the other mouse carcinogenicity study ( MRID No. 00122732; Accession No. 071312, 071313, 071314, 250463, and 250464). When the data of these two studies are analyzed together, they provide a reasonable understanding of the carcinogenicity of acifluorfen on mice.

( 2) In a 18 month carcinogenicity study ( MRID No. 00122732; Accession No's. 071312, 071313, 071314, 250463, and 250464), Tackle ( 20.4 23.2% a. i.) was administered to B6C3F1 mice ( 60/ sex/ dose) in the diet at levels of 0, 625, 1250 or 2500 ppm ( 0, 119, 259 or 655 mg/ kg/ day for males and 0, 143, 313 or 711 mg/ kg/ day for females) for 18 months.

An increase in mortality was seen in high dose males ( control, 1/ 60; high dose, 10/ 60). Body weights in all treated mice were reduced when compared to controls. Beginning at week 2 for mid and high dose males and week 6 for low dose males, body weights were significantly reduced ( p< 0.01) relative to controls. The body weight decrease for low, mid, and high dose males was 8%, 10% and 23% of the controls, respectively at week 13 and 10%, 13% and 25% of the controls, respectively at week 79. Similar results were obtained with females, except that reduced body weights of low and mid dose females were not significant until week 13. The body weight decrease for low, mid, and highdose females was 6%, 5% and 14% of the controls, respectively at week 13 and 11%, 22% and 34% of the controls, respectively at week 79. Mean food consumption in highdose males was higher relative to the controls most of the study period.

Mean corpuscular volume ( MCV) and segmented neutrophil counts were decreased and lymphocyte and RBC counts were increased compared to controls in all treated males at final sacrifice. Segmented neutrophil counts was decreased and lymphocyte counts were increased in all treated females ( at interim sacrifice) and in mid and high dose females ( at final sacrifice) when compared to controls.

Mean absolute and relative liver weights of treated males and females were greater than the controls at interim and final sacrifice. Gross pathology showed an apparent doserelated increase in incidence of liver masses in treated males when compared to the controls at final sacrifice. In high dose females, an increase in incidence ( 37%) of liver masses was observed. The incidence of white foci ( 1 mm) on the nonglandular portion of  30 the stomach were seen in high dose males and mid and high dose females. In addition, one high dose male and one high dose female each had an ulcer of the stomach.

Acifluorfen was associated with statistically significant positive trends for liver tumors ( adenomas, carcinomas, and adenomas/ carcinomas combined) and stomach tumors ( papillomas) in both sexes. The liver tumors were significantly increased above the controls at the lowest dose level tested ( 625 ppm) in male mice and at the highest dose level tested ( 2500 ppm) in both sexes. In addition, the stomach tumors were significantly increased above the controls at the highest dose level tested ( 2500 ppm) in both sexes. The highest dose tested was considered adequate in evaluation of carcinogenic potential of the test chemical.

The NOAEL for systemic toxicity is not established. The LOAEL for systemic toxicity is equal or lower than 625 ppm ( 119 and 143 mg/ kg/ day for males and females, respectively) based on reduced body weight, increased absolute and relative liver weights, and changes in hematologic parameters ( decreased MCV counts, decreased segmented neutrophil counts, increased RBC counts, and increased lymphocyte counts). This study is classified as Acceptable/ Guideline and satisfies the Subdivision F guideline requirement for a carcinogenicity study ( 83 2b) in mice.

Chronic toxicity/ carcinogenicity in rats [ feeding]

In a two year feeding/ carcinogenicity study ( MRID No. 00128353; Accession No's. 071315 through 071317 and 250289 through 250792), Tackle ( 19.1 25.6% a. i.) was administered to Fischer 344 rats ( 73/ sex/ dose) in the diet at levels of 0, 25, 150, 500, 2500 or 5000 ppm for 2 years ( 0, 1.25, 7.50, 25.0, 125 or 250 mg/ kg/ day based on a conversion factor of 1 ppm= 0.05 mg/ kg/ day).

All males and 61/ 65 females in 5000 ppm group died before termination of the study. Mean body weight was significantly decreased in males at the 2500 ( 7 9%) and 5000 ppm ( 18 35%) throughout the study relative to the controls. In females, the body weight was also decreased in 2500 ( 6 16%) and 5000 ppm ( 11 28%) groups relative to the controls.

Red cell counts, hematocrit and hemoglobin values were significantly lower in the 5000 ppm males when compared to the controls.

In the 5000 ppm males and females, blood glucose, triglyceride, and serum globulin and total protein were significantly lower than those of the control animals; BUN, creatinine and alkaline phosphatase were significantly higher than those of the control animals. In the 2500 ppm males, blood glucose, triglyceride and globulin were significantly lower and BUN was significantly higher when compared to the control animals. In the 2500 ppm females, triglyceride and globulin were significantly lower and alkaline phosphatase was significantly higher when compared to the control animals.

Gross necropsy showed that there was an increased incidence of kidney and liver discoloration, stomach ulcers and reduced testes size for the 5000 ppm males when  31 compared to the controls. In females, an increased incidence of kidney lesions ( distended pelvis/ calculi) was observed in the 2500 and 5000 ppm animals and stomach ulceration was observed in the 5000 ppm animals when compared to the controls.

In 2500 ppm males, there were increases in absolute and relative liver weights, decreases in spleen weights, and increases in relative kidney weights. In 5000 ppm males, there were increases in liver weights and decreases in spleen weights. In females at 2500 and 5000 ppm, there were increases in relative liver weights and decreases in heart weights.

Histologically, there were increased incidences of acidophilic cells in the liver of the 5000 ppm group in both sexes and in the 2500 ppm females. In addition, there were increased incidences of nephritis/ pyelonephritis in 2500 and 5000 ppm group females. An increase in the incidence of stomach ulcer was seen in 5000 ppm males and females. Testicular atrophy was also seen in 5000 ppm males.

Under the condition of the study, no treatment related increase in tumor incidence was found in the acifluorfen treated rats.

The NOAEL for systemic toxicity is 500 ppm ( 25 mg/ kg/ day); the LOAEL is 2500 ppm ( 125 mg/ kg/ day) based on reduced body weight, increased absolute and relative liver weights and increased kidney weights, increased incidence of nephritis/ pyelonephritis, increased incidence of acidophilic cells in the liver, and related changes in clinical chemistry parameters The highest dose ( 5000 ppm) tested was considered excessively toxic in evaluation of carcinogenic potential of the test chemical based on findings of reduced body weights, increased mortality, increased liver weights and liver enzyme changes ( alkaline phosphatase), renal changes ( nephritis and pyelonephritis), stomach ulcers and decreased testes size. This study is classified as Acceptable/ guideline and satisfies the guideline data requirement for a combined chronic/ carcinogenicity study ( 83 5) in rats.

Another rat chronic feeding study ( MRID No. 00087478) with Blazer was also conducted by Rohm and Haas. The DER ( HED Doc. No. 001099 and 001251) for this study indicated no increase in any tumor incidence in treated animals relative to the controls. However, the experimental design of the study used multiple shifts in dose levels at different durations of the study. It is difficult to establish at what dose levels or times that changes in biological parameters occurred. However, when the data of these two studies are analyzed together, they provide a reasonable understanding of the chronic toxicity of acifluorfen in rats.


[Federal Register Volume 77, Number 114 (Wednesday, June 13, 2012)]
[Notices]
[Page 35370]
[FR Doc No: 2012-14320]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

Notice of Combined Filings

    Take notice that the Commission has received the following Natural
Gas Pipeline Rate and Refund Report filings:

Filings Instituting Proceedings

    Docket Numbers: RP12-782-000.
    Applicants: Atmos Energy Corporation.
    Description: Petition for Temporary Waivers and Request for
Expedited Action and Shortened Comment Period of Atmos Energy
Corporation.
    Filed Date: 5/31/12.
    Accession Number: 20120531-5400
    Comments Due: 5 p.m. ET 6/12/12.

    Docket Numbers: RP12-790-000.
    Applicants: Eastern Shore Natural Gas Company.
    Description: Storage Tracker 06-2012 to be effective 6/1/2012.
    Filed Date: 6/5/12.
    Accession Number: 20120605-5050.
    Comments Due: 5 p.m. ET 6/18/12.

    Any person desiring to intervene or protest in any of the above
proceedings must file in accordance with Rules 211 and 214 of the
Commission's Regulations (18 CFR 385.211 and 385.214) on or before 5:00
p.m. Eastern time on the specified comment date. Protests may be
considered, but intervention is necessary to become a party to the
proceeding.

Filings in Existing Proceedings

    Docket Numbers: RP12-739-001.
    Applicants: Texas Gas Transmission, LLC.
    Description: Amendment to RP12-739-000 to be effective 6/17/2012.
    Filed Date: 6/6/12.
    Accession Number: 20120606-5012.
    Comments Due: 5 p.m. ET 6/18/12.

    Any person desiring to protest in any the above proceedings must
file in accordance with Rule 211 of the Commission's Regulations (18
CFR 385.211) on or before 5:00 p.m. Eastern time on the specified
comment date.
    The filings are accessible in the Commission's eLibrary system by
clicking on the links or querying the docket number.
    eFiling is encouraged. More detailed information relating to filing
requirements, interventions, protests, and service can be found at:
http://www.ferc.gov/docs-filing/efiling/filing-req.pdf. For other
information, call<PHONE_NUMBER> (toll free). For TTY, call (202) 502-
8659.

    Dated: June 6, 2012.
Nathaniel J. Davis, Sr.
Deputy Secretary
[FR Doc. 2012-14320 Filed 6-12-12; 8:45 am]
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[Federal Register: January 20, 2010 (Volume 75, Number 12)]
[Notices]
[Page 3218]
[DOCID:fr20ja10-54]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Project No. 12496-001]

Rugraw, Inc.; Notice of Preliminary Permit Application Accepted
for Filing and Soliciting Comments, Motions To Intervene, and Competing
Applications

January 11, 2010.
    On December 17, 2009, Rugraw, Inc. filed an application for a
preliminary permit, pursuant to section 4(f) of the Federal Power Act,
proposing to study the feasibility of the Lassen Lodge Hydroelectric
Project, which would be comprised of a single, 5.1 megawatt development
on the South Fork Battle Creek. The proposed project would be located
in Tehama County, California, near the unincorporated town of Mineral.
    The proposed project would consist of the following facilities:
    (1) An 80-feet-long, 5-feet-high diversion structure incorporating
the existing natural features (large boulders, etc.) and grout; (2) a
new reservoir with a proposed surface area of approximately 0.5 acre,
with a storage capacity of approximately 2.5 acres, and with a normal
water surface elevation of 4,315 feet mean sea level; (3) a 7,900-feet-
long, 42-inch-diameter low pressure pipeline attached to an
approximately 6,100-feet-long high pressure penstock; (4) a powerhouse
containing a horizontal Pelton-type turbine/generator unit with an
installed capacity of 5.1 megawatts; (5) a tailrace; (6) a proposed 60
KV-transmission line approximately 10 miles long; and (7) appurtenant
facilities.
    The proposed project would have an average annual generation of
23.9 gigawatt-hours.
    Applicant Contact: Mr. Thomas Keegan; ECORP Consulting, Inc., 2525
Warren Drive, Rocklin, California 95677; phone:<PHONE_NUMBER>.
    FERC Contact: Kenneth Hogan,<PHONE_NUMBER> or via e-mail at:
<EMAIL_ADDRESS>    Deadline for filing comments, motions to intervene, competing
applications (without notices of intent), or notices of intent to file
competing applications: 60 days from the issuance of this notice.
Competing applications and notices of intent must meet the requirements
of 18 CFR 4.36. Comments, motions to intervene, notices of intent, and
competing applications may be filed electronically via the Internet.
See 18 CFR 385.2001(a)(1)(iii) and the instructions on the Commission's
Web site (http://www.ferc.gov/docs-filing/ferconline.asp) under the
``eFiling'' link. For a simpler method of submitting text only
comments, click on ``Quick Comment.'' For assistance, please contact
FERC Online Support at<EMAIL_ADDRESS>call toll-free at
(866) 208-3676; or, for TTY, contact<PHONE_NUMBER>. Although the
Commission strongly encourages electronic filing, documents may also be
paper-filed. To paper-file, mail an original and eight copies to:
Kimberly D. Bose, Secretary, Federal Energy Regulatory Commission, 888
First Street, NE., Washington, DC 20426.
    More information about this project, including a copy of the
application, can be viewed or printed on the ``eLibrary'' link of
Commission's Web site at http://www.ferc.gov/docs-filing/elibrary.asp.
Enter the docket number (P-12496) in the docket number field to access
the document. For assistance, contact FERC Online Support.

Kimberly D. Bose,
Secretary.
[FR Doc. 2010-914 Filed 1-19-10; 8:45 am]
BILLING CODE 6717-01-P


[Federal Register Volume 79, Number 227 (Tuesday, November 25, 2014)]
[Notices]
[Pages 70272-70273]
[FR Doc No: 2014-27889]

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

[U.S. DOT Docket Number NHTSA-2014--0111]

Reports, Forms, and Record Keeping Requirements

AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation.

ACTION: Request for public comment on the extension of a currently
approved collection of information.

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SUMMARY: Before a Federal agency can collect certain information from
the public, it must receive approval from the Office of Management and
Budget (OMB). Under procedures established by the Paperwork Reduction
Act of 1995, before seeking OMB approval, Federal agencies must solicit
public comment on proposed collections of information, including
extensions and reinstatement of previously approved collections.

    This document describes one collection of information for which
NHTSA intends to seek OMB approval.

DATES: Comments must be received on or before January 26, 2015.

ADDRESSES: Comments must refer to the docket notice numbers cited at
the beginning of this notice and be submitted to Docket Management,
Room W12-140, Ground level, 1200 New Jersey Ave. SE., Washington, DC
20590 by any of the following methods.
     Federal eRulemaking Portal: http://www.regulations.gov.
Follow the instructions for submitting comments.
     Mail: Docket Management Facility; U.S. Department of
Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor,
Room W12-140, Washington, DC 20590.
     Hand Delivery/Courier: 1200 New Jersey Avenue SE., West
Building Ground Floor, Room W12-140, Washington, DC 20590, between 9
a.m. and 5 p.m., Monday through Friday, except Federal Holidays.
Telephone: 1-800-647-5527.
     Fax:<PHONE_NUMBER>.
    Instructions: For detailed instructions on submitting comments and
additional information on the rulemaking process, see the Public
Participation heading of the Supplementary Information section of this
document. Note that all comments received will be posted without change
to http://www.regulations.gov, including any personal information
provided. Please see the Privacy Act heading below.
    Privacy Act: Anyone is able to search the electronic form of all
comments received into any of our dockets by the name of the individual
submitting the comment (or signing the comment, if submitted on behalf
of an association, business, labor union, etc.). You may review DOT's
complete Privacy Act Statement in the Federal Register published on
April 11, 2000 (65 FR 19477) or you may visit http://www.regulations.gov .
    Docket: For access to the docket to read background documents or
comments received, go to the street address listed above. The internet
access to the docket will be at http://www.regulations.gov. Follow the
online instructions for accessing the dockets.

FOR FURTHER INFORMATION CONTACT: Complete copies of each request for
collection of information may be obtained at no charge from Mr. Hisham
Mohamed, NHTSA 1200 New Jersey Ave. SE., West Building, Room W43-437,
NVS-131, Washington, DC 20590.
    Mr. Mohamed's telephone number is<PHONE_NUMBER>. Please identify
the relevant collection of information by referring to its OMB Control
Number.

SUPPLEMENTARY INFORMATION: Under the Paperwork Reduction Act of 1995,
before an agency submits a proposed collection of information to OMB
for approval, it must first publish a document in the Federal Register
providing a 60-day comment period and otherwise consult with members of
the public and affected agencies concerning each proposed collection of
information. The OMB has promulgated regulations describing what must
be included in such a document. Under OMB's regulation at 5 CFR
1320.8(d), an agency must ask for public comment on the following:
    (i) Whether the proposed collection of information is necessary for
the proper performance of the functions of the agency, including
whether the information will have practical utility;
    (ii) the accuracy of the agency's estimate of the burden of the
proposed collection of information, including the validity of the
methodology and assumptions used;
    (iii) how to enhance the quality, utility, and clarity of the
information to be collected;
    (iv) how to minimize the burden of the collection of information on
those who are to respond, including the use of appropriate automated,
electronic, mechanical, or other technological collection techniques or
other forms of information technology, e.g. permitting electronic
submission of responses.
    In compliance with these requirements, NHTSA asks for public
comments on the following proposed collection of information for which
the agency is seeking approval from OMB:
    Title: 49 CFR 575--Consumer Information Regulations (sections 103
and 105).
    OMB Control Number: 2127-0049.
    Form Number: None.
    Affected Public: Motor vehicle manufacturers of light trucks and
utility vehicles.
    Requested Expiration Date of Approval: Three years from approval
date.
    Abstract: NHTSA must ensure that motor vehicle manufacturers comply
with 49 CFR part 575, Consumer Information Regulation Part 575.103
Truck-camper loading and Part 575.105 Utility Vehicles. Part 575.103,
requires that manufacturers of light trucks that are capable of
accommodating slide-in campers provide information on the cargo weight
rating and the longitudinal limits within which the center of gravity
for the cargo weight rating should be located. Part 575.105, requires
that manufacturers of utility vehicles affix a sticker in a prominent
location alerting drivers that the particular handling and maneuvering
characteristics of utility vehicles require special driving practices
when these vehicles are operated.
    Estimated Annual Burden: 300 hours.
    Number of Respondents: 15.
    Based on prior years' manufacturer submissions, the agency
estimates that 15 responses will be submitted annually. Currently 19
light truck manufacturers comply with 49 CFR part 575. These
manufacturers file one response annually and submit an additional
response when they introduce a new model. Changes are rarely filed with
the agency, but we estimate that at least three manufacturers will
alter their information because of model changes. The light truck
manufacturers gather only pre-existing data for the purposes of this
regulation. Based on previous years' manufacturer information, the
agency estimates that light truck manufacturers use a total of 20
hours; to gather and arrange the data in its proper format (9 hours),
to distribute the information to its dealerships and attach labels to
light trucks that are capable of accommodating slide-in campers (4
hours), and to print the labels and utility vehicle information in the
owner's manual or a separate document included with the owner's manual
(7 hours). The estimated annual burden hour is 300 hours. This number
reflects the total responses (15) times the total hours (20). Prior
years' manufacturer information indicates that it takes an average of
$37.00 per hour for professional and clerical staff to gather data,
distribute and print material. Therefore, the agency estimates that the
annual cost associated with the burden hours is $11,100 ($37.00 per
hour x 300 burden hours).
    Comments are invited on: Whether the proposed collection of
information is necessary for the proper performance of the functions of
the Department, including whether the information will have practical
utility; the accuracy of the Department's estimate of the burden of the
proposed information collection; ways to enhance the quality, utility
and clarity of the information to be collected; and ways to minimize
the burden of the collection of information on respondents, including
the use of automated collection techniques or other forms of
information technology.

R. Ryan Posten,
Associate Administrator for Rulemaking.
[FR Doc. 2014-27889 Filed 11-24-14; 8:45 am]
BILLING CODE 4910-59-P