Occupational asthma reported in baker and miller exposed to flour dusts (wheat, rye, and soya); [Malo] Allergic contact dermatitis in bakers; Flour may contain flavors, dyes, enzymes, bleaches, and other additives. It may cause both immediate and delayed allergic skin reactions. [Marks] Danger of airway sensitization for cereal (rye, wheat) flour dusts; [MAK] The work-related illnesses from flour exposure include rhinitis, conjunctivitis, asthma, and dermatitis. Bakers' asthma continues to be a significant problem, especially in smaller facilities. Average years of exposure for bakers' asthma are 8-9 years (allergic rhinitis) and 13-16 years (asthma). Atopy and exposure to flour dust antigens are the major contributing factors in the development of bakers' asthma. Enzymes used in baking, such as alpha-amylase, sensitize 5% to 24% of symptomatic bakers. A 1985 study of 314 bakery workers in Switzerland found a prevalence of 74% for respiratory allergy (rhinitis or asthma). The TLV covers all types of flour. Most studied is wheat flour, but there is cross-reactivity between the different cereal grains, including wheat, rye, corn, and barley. [ACGIH] Flour dust (includes wheat and alpha-amylase allergens) can cause contact urticaria and Type IV contact dermatitis. [
PMID 22411214] In the 424 subjects (40% bakers, 26% counterhands, 7% confectioners, 14% managers, and 13% ex-bakers), sensitization rates were 31% for flour, 28% for rye, and 2% for fungal alpha-amylase. [Reference #1]