ACGIH® Threshold Limit Values (TLVs®) and Biological Exposure Indices (BEIs®): ACGIH® is a private, not-for-profit, nongovernmental corporation. It is not a standards setting body. ACGIH® is a scientific association that develops recommendations or guidelines to assist in the control of occupational health hazards. TLVs® and BEIs® are health-based values and are not intended to be used as legal standards. Threshold Limit Values (TLVs®) refer to airborne concentrations of chemical substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, over a working lifetime, without adverse effects. Biological Exposure Indices (BEIs®) are guidance values for assessing biological monitoring results - concentrations of chemicals in biological media (e.g., blood, urine). BEIs® represent the levels of determinants that are most likely to be observed in specimens collected from healthy workers who have been exposed to chemicals in the same extent as workers with inhalation exposure at the TLV®. Since ACGIH® TLVsand BEIs® are based solely on health factors, there is no consideration given to economic or technical feasibility. ACGIH® does not believe that TLVs® and BEIs® should be adopted as standards without an analysis of other factors necessary to make appropriate risk management decisions (e.g., control options, technical and economic factors, etc For more information on TLVs®, please go to http://www.acgih.org/TLV/. The TLVs® and BEIs® are copyrighted by ACGIH??and are not publicly available. However, they can be purchased in their entirety on the ACGIH® website at http://www.acgih.org/store/. The ACGIH® TLVs® are widely recognized as authoritative, and are required to be included on safety data sheets by the OSHA Hazard Communication Standard. See more from topic source: https://www.osha.gov/html/a-z-index.html