Tell me the class lllb with the highest exposure limit whose safety is labelling standards.
select ?ent where { ?ent wdt:P31 wd:Q21009059 . ?ent wdt:P2405 ?obj . ?ent wdt:P4952 wd:Q51139288 } ORDER BY DESC(?obj)LIMIT 5 
class iiib combustible liquid: Q21009059 nfpa 704: standard system for the identification of the hazards of materials for emergency response: Q51139288