Do I have to wear a respirator when I mill malt? Do I have to shave my beard?
The Safety Exchange Says: You must wear a respirator when milling malt if your employer has determined through a hazard assessment that you will be exposed to respiratory hazards above the OSHA permissible exposure limit (PEL) and the exposure cannot be otherwise reduced to safe levels using engineering controls. This assessment may require air sampling to evaluate the level of exposure. In such a case the employer needs to have a respiratory protection program that details such things as respirators use, types, maintenance and inspection, fit testing, medical surveillance, and more. More information can be found at osha.gov.
On the other hand, when dust levels are kept lower than the PEL by good housekeeping, ventilation, and such, your employer may offer a voluntary program where you, the employee, can choose whether to wear a respirator. In a voluntary program the employer can provide the respirators but cannot mandate their use.
As for your beard, nearly all respirator types require close contact with the skin of the face (i.e. clean shaven) in order to be effective. If you have a required respiratory protection program you will probably need to lose some or all of the beard in order to pass a respirator fit test, or you will need a very expensive alternative respirator called a powered air purifying respirator.