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Engineering Controls Database

Dairy Barns – Control of Organic Dusts from Bedding Choppers in Dairy Barns

Farmers use bedding choppers to chop bales of hay or straw for dairy cow bedding. The chopping of bedding material is hazardous because it is usually made of low quality straw or hay that contains high levels of microorganisms such as bacteria or fungi. These microorganisms are released into the air during the chopping process creating a respiratory exposure hazard.
The chopping of bedding materials places the farmer at risk for acute and chronic respiratory and systemic health problems such as asthma, chronic bronchitis, hypersensitivity pneumonitis, and organic dust toxic syndrome. Bedding choppers powered by gasoline engines present an additional hazard because they produce carbon monoxide, a poisonous gas.
WET CHOPPING

During bedding chopping, small quantities of water are added to the bales of hay and straw before chopping. Since the bedding had low levels of moisture, the addition of water was acceptable to the farmers. The wet chopping method involves adding approximately 1 to 2 pints of water to the cut side of the bale immediately before chopping. A small sprinkling can is used to distribute moisture throughout the bales (Figure 1).
Figure 1

Figure 1


SUBSTITUTION/ RESPIRATORY PROTECTION

Significant dust exposures can still occur during wet chopping. Additional controls may be needed depending on the quality of the hay used for chopping. Bales of hay that are visibly moldy (indicating severe contamination by microorganisms) pose the greatest exposure risk. Substitution of less contaminated hay for bedding chopping is recommended. When substitution is not possible, the use of respiratory protective equipment (respirators) is recommended. The Occupational Safety and Health Administration (OSHA) Respiratory Protection Standard (29 CFR* 1910.134) (www.osha.gov/SLTC/etools/respiratory/index.html) should be followed for respirator use. The provisions of the program include procedures for se¬lection, medical evaluation, fit testing, training, use, and care of respirators.

BEDDING CHOPPERS/BARN VENTILATION

All gasoline-powered engines produce carbon monoxide. The use of pressure-washing units powered by gasoline engines inside agricultural buildings has caused many cases of carbon monoxide poisoning and fatalities. Gasoline-powered bedding choppers are also hazardous, even though they are used for short time periods. They should be used only in well-ventilated barn areas to prevent carbon monoxide poisonings. Electrically powered bedding choppers are available and may be a better overall solution.
NIOSH [1997]. Hazard control. Control of organic dusts from bedding choppers in dairy barns. Cincinnati, OH. U.S. Department of Health and Human Services, Public Health Service, Center for Disease Control and Prevention, National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication 97-103.
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dairy cattle
dairy cattle
dairy cattle farming
dairy cattle farming
milk production
milk production
During bedding chopping, worker exposure to airborne organic dusts has been reduced 80% by adding small quantities of water to the bales of hay and straw before chopping.