Page 1 Health Hazard Evaluation Report 2009-0131-3171 Evaluation of Sensitization and Exposure to Flour Dust, Spices, and Other Ingredients Among Poultry Breading Workers Report No. 2009-0131-3171 April 2013 Elena H

Page 18

Health Hazard Evaluation Report 2009-0131-3171

membrane problems related to flour dust and 12 participants reported having been diagnosed 

with allergy to flour by a healthcare professional, the burden of suspected disease related to 

exposure to flour dust and other ingredients is much higher. Thirty-four percent of higher-

exposure and 26% of lower-exposure group participants had work-related asthma symptoms, 

yet only 14% of the higher-exposure group and 9% of the lower-exposure group were 

taking asthma medicine. This suggests undiagnosed occupational asthma among employees. 

In addition, 37% of participants reported symptoms of occupational allergic rhinitis. 

Participants with atopy were significantly more likely to be sensitized to wheat and other 

ingredients, consistent with past studies of bakery and food allergy.

Work-related asthma symptoms were significantly more common in participants sensitized to 

flour dust, wheat, corn, or onion than in those who were not sensitized. In addition to baker’s 

asthma, IgE-mediated asthma and other allergic disease due to corn, soybean, onion, garlic, 

and paprika have been reported in the medical literature [Park and Nahm 1997; Schöll and 

Jensen-Jarolim 2004; Cummings et al. 2010]. Sensitization to these allergens was common 

among participants, regardless of exposure group. 

Work-related episodes of coughing were common among participants, regardless of 

sensitization, likely representing general irritation from dust. Prevalences of work-related 

allergic rhinitis and rhinoconjunctivitis symptoms were also reported by more than 20% of 

all participants, regardless of sensitization. Work-related irritation symptoms are reported in 

the medical literature to be more common than allergic symptoms among employees exposed 

to flour dust. 

Inhalable wheat (r = 0.89) and inhalable soy (r = 0.79) were positively correlated with 

the inhalable flour dust concentrations. Other studies have also documented significant 

correlation between inhalable wheat and inhalable flour dust [Baatjies et al. 2010; Page et 

al. 2010]. This supports the use of inhalable flour dust sampling for monitoring exposures 

instead of the more complicated and expensive inhalable wheat sampling. 

The preferred method to control flour dust exposures is through engineering controls. 

The plant management implemented local exhaust ventilation, but it was inadequate and 

exposures still remain high. We did not quantitatively evaluate the local exhaust ventilation 

as part of this HHE, but we did note that some local exhaust ventilation units were not 

connected and were not adequately controlling exposures. Until engineering controls are 

documented to lower exposures below the ACGIH TLV, respiratory protection should be 

worn throughout the plant. 

The implementation of a respiratory protection program and the selection of respirators 

should follow the OSHA respiratory protection standard [29 CFR 1910.134] and the 

NIOSH respirator selection logic [NIOSH 2004]. Once engineering controls (i.e., 

ventilation changes) have been implemented, employees’ exposures should be reevaluated. 

Once exposures have been reduced, the respiratory protection requirement should be 

reassessed using the NIOSH respirator selection logic because some jobs may no longer 

need respiratory protection and others may need lower levels of protection. For jobs that 

---

Page 19

Health Hazard Evaluation Report 2009-0131-3171

still require respiratory protection, task-based exposures should be evaluated to identify 

specific tasks that require respirators and those that may not. This may also help to prioritize 

engineering control recommendations. 

Conclusions 

Nearly all plant employees whom we sampled were overexposed to flour dust from the batter 

mixes and breading dusts. Dust concentrations for all employees we sampled, except frozen 

shipping and some receiving and line 6 employees, exceeded the ACGIH TLV for flour dust 

during our evaluation. Lack of or inadequate ventilation controls and poor work practices 

contributed to high flour dust exposures. Sensitization to flour dust, wheat, spices, and other 

ingredients was highly prevalent. There were high prevalences of work-related asthma 

symptoms, cough, and rhinoconjunctivitis among all employees. Our evaluation suggests that 

some employees have undiagnosed occupational asthma. 

Recommendations

On the basis of our findings, we recommend the actions listed below. We encourage the 

poultry breading plant to use a labor-management health and safety committee or working 

group to discuss our recommendations and develop an action plan. Those involved in the 

work can best set priorities and assess the feasibility of our recommendations for the specific 

situation at this poultry breading plant. 

Our recommendations are based on an approach known as the hierarchy of controls 

(Appendix C: Occupational Exposure Limits and Health Effects). This approach groups 

actions by their likely effectiveness in reducing or removing hazards. In most cases, the 

preferred approach is to eliminate hazardous materials or processes and install engineering 

controls to reduce exposure or shield employees. Until such controls are in place, or if they 

are not effective or feasible, administrative measures and personal protective equipment may 

be needed. 

Engineering Controls

Engineering controls reduce exposures to employees by removing the hazard from the 

process or placing a barrier between the hazard and the employee. Engineering controls 

are very effective at protecting employees without placing primary responsibility of 

implementation on the employee. 

1.  Evaluate the local exhaust ventilation systems to determine if they can be altered to 

lower dust exposures below the ACGIH TLV for flour dust. If the current systems 

cannot achieve these specified limits, modify or replace the systems. 

2.  Use a pneumatic transfer system equipped with a bag dump station to transfer 

powdered ingredients to the dispensing hoppers. The system should be equipped 

---