Chemicals classified as __________ can cause a severe allergic reaction

• A. Sensitizers
• B. Irritants
• C. Corrosives
• D. Neurotoxins

Answer: (A)

Chemicals that can trigger an immune-mediated allergic reaction are known as sensitizers. The key idea is that exposure to a sensitizer can prime the immune system so that future exposures provoke a strong, often severe, allergic response. This differs from irritants, which simply cause inflammation at the contact site, and from corrosives, which damage tissue, or neurotoxins, which affect the nervous system. With sensitizers, the first exposure may cause little or no reaction, but once the body has been sensitized, even small later exposures can lead to serious reactions such as bronchospasm, hives, or anaphylaxis. This makes sensitizers particularly important to recognize in HazMat work, where protecting workers from even low-level exposures and monitoring for sensitization is crucial.