Agent Name

Flour (wheat, rye and soya)

Major Category

Biological Agents


Plant-Derived Allergens


Flour exposures occur in milling operations (milling and packing) and baking operations (working as bakers and pastry makers). Also farm animal feeders may be exposed to flour dust when feeds contain cereal flours. The highest exposures occur during mixing and baking. [ACGIH]


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]

Reference Link

Sensitisation to cereal flour allergens is a major determinant of elevated exhaled nitric oxide in bakers.

Exposure Assessment
Skin Designation (ACGIH)



0.5 mg/m3, inhalable particulate matter

Adverse Effects
Skin Sensitizer




Links to Other NLM Databases
Toxicity Information


Related Information in HazMap

Occupational diseases associated with exposure to this agent: