NIOSHTIC-2 Publications Search

Baker's asthma: old disease persists.

Massachusetts Department of Public Health Occupational Health Surveillance Program
SENSOR Occup Lung Dis Bull 2009 May; :1-2
The earliest reports of illness associated with milling flour and baking were recorded in 1713, with descriptions of cough, shortness of breath, hoarseness, asthma and eye problems among bakers. Baker's asthma and the underlying causes were further described in the 1970s and 1980s, as immunological techniques were developed that could measure allergens. It became clear that baking and wheat flour, in particular, caused irritation, sensitization and asthma, including detectable IgE against certain ingredients. Allergic sensitization can lead to asthma and baker's eczema; eye, nose and respiratory irritation were more common adverse health effects.(1) Peer-reviewed medical articles about wheat and other cereal flours, such as rye and barley, helped establish the evidence regarding the capacity of proteins from a variety of flours to induce specific IgE sensitization after inhalation. Information was subsequently published about amylase (enzyme), a dough conditioner that is routinely added to baking flour (in milligrams per kilogram) to hasten the baking process and improve bread quality. This enzyme is frequently derived from Aspergillus oryzae and added to flour to compensate for low natural amylase levels in cereal flour and economize the baking process. In one study, efforts to reduce baker's asthma by reducing overall inhalable dust failed to reduce the incidence of baker's asthma in the UK.(2) Researchers concluded that amylase was likely the most important cause of allergy.(2) Short term peak exposures may contribute to sensitization, even when exposures appear low over a full work shift.(3) There are now several allergens documented to cause baker's asthma; baker's asthma is often preceded by rhinitis, and atopy is frequently present.(4) The identity of a causative agent in any single case may be unclear because employees are frequently exposed to many agents at once, but the risk is increased by high exposure to bakery dust. Baker's asthma is one of the most common forms of occupational asthma.(4) In France, baker's asthma ranked first among cases reported to the national observatory of occupational asthma.(5) It is estimated that 7-15% of bakers have baker's asthma.(6,7) Nine cases of baker's asthma have been reported to the Occupational Health Surveillance Program (OHSP) from 1993 to the present. Two cases are presented below from a commercial bakery. Four persons with baker's asthma were reported in retail bakeries or stores, and (3) others in food manufacturing, including a dog biscuit producer. These two cases of baker's asthma were diagnosed and reported among employees at a commercial bakery in Massachusetts by a primary care physician and allergist respectively. They each had worked for years before they developed asthma, had different jobs, and were assigned to different areas of the plant. Both were immigrants, with limited English proficiency, though from different countries, speaking different languages. Neither had seen an occupational medicine physician. These 2 cases of baker's asthma were diagnosed and managed because the physicians asked their patients about work. OHSP has an ongoing project to promote the collection of occupational information by community health centers.
Occupational-health; Work-environment; Workers; Occupational-exposure; Respiratory-system-disorders; Pulmonary-system-disorders; Bronchial-asthma; Surveillance-programs; Health-hazards; Worker-health; Occupational-diseases; Case-studies; Disease-prevention; Bakery-workers; Milling-industry; Food; Food-handlers; Food-processing-workers; Food-services; Foodstuff; Clinical-diagnosis; Allergens; Allergic-reactions; Allergies; Employee-exposure; Immunological-tests; Proteins; Enzymes
Massachusetts Department of Public Health, Occupational Health Surveillance Program, 250 Washington Street, 6th Floor, Boston, MA 02108
Publication Date
Document Type
Funding Type
Cooperative Agreement
Fiscal Year
Identifying No.
Priority Area
Healthcare and Social Assistance
Source Name
SENSOR Occupational Lung Disease Bulletin
Performing Organization
Massachusetts State Department of Public Health
Page last reviewed: May 11, 2023
Content source: National Institute for Occupational Safety and Health Education and Information Division