What is {safety classification and labelling} of {nitrogen dioxide} that is {NFPA Health} is {3} ?
If nitrogen dioxide has a NFPA label of 3, what is it's safety classification?
What is the safety classification of nitrogen dioxide with a NFPA Health label of 3?
SELECT ?i WHERE { resource:nitrogen_dioxide property:safety_classification_and_labelling ?z . ?z property:safety_classification_and_labelling ?i . FILTER ( ?d = 3 ) . ?z property:NFPA_Health ?d }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q207895> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P4952> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P993> <3>
} 

SELECT ?obj WHERE { wd:Q207895 p:P4952 ?s . ?s ps:P4952 ?obj . ?s pq:P993 ?x filter(contains(?x , '3')) }