Element Of Death Suddenly Cyanide Has A High - And Lethal - Profile

February 25, 1986|by TIM BLANGGER, The Morning Call

Eight deaths later, it is still the only suspect in custody.

It is potassium cyanide, a white, odorless substance known to chemists by its nomenclature, KCN. It's available generally in three forms: as briquettes slightly smaller than those used in charcoal fires, in a granular form and as a fine powder. All three forms are used in a wide variety of industrial processes.

The chemical, authorities say, was also used to contaminate Extra-Strength Tylenol capsules linked to the Feb. 8 death of a New York State woman and in the seven deaths in the Chicago area during October 1982.

No arrests have been made in connection with the Chicago deaths. Authorities are still investigating the recent death of Diane Elsroth, a 23- year-old woman who died after taking Tylenol capsules laced with the poison, but police in Yonkers, Westchester County, have said they have no suspects.

All that remains is the chemical itself, which is widely used in chemical processes and is readily available, chemical industry spokesmen say.

Besides heightening public awareness of product tampering in general, both highly publicized cases have brought attention to a chemical that already has a high public profile. Most people associate cyanide with the pill the spy swallows before he divulges information to the enemy, or the mainactor in the gas chamber execution, but are less familiar with the many industrial uses of the chemical.

Potassium cyanide, for example, is used to make indigo dye, used in dying blue jeans. Sodium cyanide, which is as toxic as potassium cyanide, is a common element in large- and small-scale electroplating processes. It is a common chemical found on many jewelers' shelves.

Of the types of cyanide products commonly used in this country, the most common and least expensive is hydrogen cyanide, also known as hydrocyanic acid, a major raw material in the manufacture of nylon. Unlike the two other forms of cyanide used in industry, hydrogen cyanide is most often a liquid.

Sodium cyanide, which is used extensively in mining as a agent to extract gold and silver from their natural ores, is slightly more expensive than hydrogen cyanide and is not as commonly used.

Potassium cyanide, of the three types of cyanide used in the United States, is the most expensive - costing an average of $1.25 a pound, and less frequently used. Like sodium cyanide, it is used in electroplating processes.

Of the three forms of potassium cyanide available, the powder form is used the least frequently of the three, according to Ronald Geyer, a senior technical service engineer for E.I. DuPont de Nemours & Co., the largest domestic manufacturer of cyanide products in the United States.

Although Johnson & Johnson officials say potassium cyanide was involved in both tampering cases, the chemical involved in the recent New York case was structurally different than the chemical involved in the Chicago cases.

Johnson & Johnson officials have refused to elaborate on the structural difference. However, Geyer, the senior Du Pont technician offered this explanation:

"In the original Tylenol situation, the purity of the potassium cyanide was such - this is my understanding - that it was taken from a drum or a bottle of essentially new material. In this (latest tampering case), the cyanide was probably taken from some process operation." Elements of metals not normally found as impurities in potassium cyanide were also discovered in the potassium cyanide involved in the New York state case.

To the untrained eye, both sodium and potassium cyanide are indistinguishabl e from each other.

True to popular conceptions, all three forms of cyanide are highly toxic. However, potassium cyanide is not as toxic as other substances, according to Dr. Robert O. Warwick Jr., who works with the Philadelphia College of Pharmacy's toxicological department.

The toxicity level for any substance is measured as the amount of the substance that is required to cause death. In general, toxicity is measured relative to body weight. If 10 grams of substance X produces the death of half of a group of laboratory rats, and if 5 grams of substance Y produces the same result, then substance Y is considered more toxic than X. For some non-toxic substances like modeling clay or crayons for example, no amount will cause death although ingesting large amounts may cause much discomfort.

A lethal dose of potassium cyanide for humans ranges from about 50 milligrams to 200 milligrams, according to Warwick, which makes it far less toxic when compared to some of the most toxic substances know to scientists. Among these are plutonium and dioxin, the active ingredient in Agent Orange, the defoliant used widely in Vietnam.

For its part, potassium cyanide has one characteristic that makes its high public image somewhat warranted: It causes death quickly, although the death is extremely painful.

Morning Call Articles