ABC of Safety in the Biological Sciences
An allergen is any substance (antigen or hapten) that can cause an allergic reaction or an allergy (any substance which stimulates IgE synthesis or causes a delayed hypersensitivity - see also Allergy).27
Allergens trigger the production of antibodies, which in turn sensitise mast cells. On re-exposure the combination of allergen and IgE antibody may cause the release of chemicals that can produce unpleasant symptoms, ranging from sneezing to rash or potentially fatal anaphylactic shock. Almost any substance in the human environment can be an allergen, including food, pollens, drugs, chemicals, plastics, insect bites, wool and cotton. Likely allergens in the laboratory are20,28-31:
d-Limonene (Histoclear, Safsolvent, Histolene)
dye powders (almost all dye powders from any source)
Working with animals can also lead to sensitisation. Adequate personal protection, such as a long sleeved gown with wrist bands, gloves and mask minimises the risk of sensitisation.32
Medical advice should be sought by persons experiencing a sensitivity reaction.