What Are Blister Agents?

Blister agents are chemical derivatives that severely damage parts of the body like the mucous membranes, lungs, eyes and skin — upon contact. They may either be in the form of vapor or in the form of liquid chemicals and are classified into lewisite, sulfur mustard and nitrogen mustard. The vapor form of the chemical disperses into the air like aerosol and will adversely affect anyone who breathes it in or on whose skin or eyes it settles. Blister agents may refer to warfare agents like mustard gas, or it may refer generally to chemicals capable of causing burns upon contact with the skin or upon inhalation.

Each type of the blister agents affect people in different ways. For instance, nitrogen mustard may either be in liquid or vapor form. Liquid nitrogen mustard is more potent than the vapor form, and exposure to the liquid nitrogen mustard causes more immediate and severe reactions upon contact. The length of contact is important in both the liquid and the vapor form of this blister agent, because the longer the exposure the more serious the effects. Some of the effects of vapor exposure include eye irritation for minor exposure or blindness in prolonged exposure.

Lewisite may affect people through a variety of channels. People may be affected through exposure to the gaseous or vapor form of this blister agent. The agent may also affect people through the liquid form, which may either come into contact with their skin in its raw liquid form or through contamination of drinking water or food. Unlike other blister agents, which may take a few hours to develop symptoms in people, symptoms of lewisite can be seen within just a few minutes of exposure. The symptoms depend on the mode of exposure. If it through ingestion, they will include cramps and severe abdominal pains. If it is by contact with the liquid form, as is the case with other blister agents, painful blisters will form on the skin and quickly develop into open sores or lesions.

Sulfur mustard affects people in the same way as lewisite. One of the two main differences is that sulfur mustard does not last as long as lewisite in the environment and will disperse shortly after it is released. The other difference is that the effects of sulfur mustard are not immediate, as they usually develop much slower. In its liquid form, sulfur mustard exposure also causes painful blisters to form on the skin of those exposed to it. Exposure to the vapor form of this blister agent can lead to problems in the respiratory tract, while prolonged exposure of the eyes to the vapor can lead to blindness.