1) Blister gas 2) Harmful 3) Noxious 4) Vesicatory 1) Causing blisters 2) Harmful 3) Noxious 4) Vesicatory 
blistering
• (n.) A vesicatory.
a blistering agent
An agent that causes blistering, such as poison ivy.
<chemistry, pharmacology> Refers to a chemical or agent that causes blisters. ... (09 Oct 1997) ... 
(ves´ĭ-kәnt) producing blisters. a chemical that does this.
Producing skin blisters.causes blistering of the skin or membrane
Ves'i·cant noun [ Latin vesica blister: confer French vésicant .] (Medicine) A vesicatory. 
Type: Term Pronunciation: ves′i-kănt Definitions: 1. An agent that produces a vesicle.
Vesicant: A substance that causes tissue blistering. A blister agent. Also called a vesicatory.Vesicants are highly reactive chemicals that combine with proteins, DNA, and other cellular components to result in cellular changes immediately after exposure. Vesicants can be used as agents of chemical warfare, as was the case in World War I, or as age...
A vesicant is a counter-irritant which raises blisters - such as cantharides.
[n] - a chemical agent that causes blistering
vesicant A blistering agent.
vesicatory noun a chemical agent that causes blistering (especially mustard gas)