Most often used in reference to chemical or radiation exposure levels. Additional Info: ALARA is not simply a phrase, but a work principle, a mindset, a culture of professional excellence. In an ideal world, one could reduce his exposure to hazardous materials to zero. In reality, reducing an exposure to zero is not always possible; certain social, technical, economic, practical, or public policy considerations will result in a small but acceptable level of risk. The best way to prevent this risk from increasing is to keep one's exposure ALARA. ALARA practices apply to virtually any substance, but are mandated for radiation workers by the U.S. Nuclear Regulatory Commission (NRC). One can never have "zero" radiation exposure because of the naturally occuring radioactivity that surrounds us - cosmic rays, natural isotopes in our body etc. Therefore, the best we can do is to add nothing to this background dose, i.e. we keep our exposure ALARA. The ALARA approach used by the NRC assumes that any?exposure to ionizing radiation carries some risk. The risk is assumed to be linear, so as one's exposure increases, so does the risk of adverse health effects. Instead of operating at or just below permissible exposure limits, one must stay as far below the exposure limits as possible. This affords a wider margin of error should a control fail or malfunction - one's exposure level may rise but still stay below the acceptable limit. Note: The OSHA Hazard Communication Standard 1910.1200 does not cover radioactive materials unless they also present aphysical or health hazard. See: The MSDS FAQ for more information. MSDS Relevance: This term may appear in a discussion of PEL's, TLV's or other exposure limits on an MSDS. It will also appear on the MSDS for any substance that contains or is contaminated with a radioactive element. The personal protective equipment and other information on the MSDS should assist you in the task of keeping your exposure levels ALARA. New work practices and procedures can also help you in your quest for ALARA excellence. There are few laboratory chemicals without hazards so consider using ALARA practices with every chemical. See also: ACGIH, PEL, TLV