Annotated PELs 4: 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^® TLVs^® and 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. Annotated PELs Tables: OSHA’s annotated PELs tables include a side-by-side comparison of OSHA PELs, Cal/OSHA PELs, NIOSH RELs and ACGIH^® TLVs^®. The TLVs^® in the annotated tables are reprinted with permission from ACGIH^®. See Important Note on ACGIH^® TLVs^®, which is also reprinted with permission from ACGIH^®. Cal/OSHA, NIOSH, and ACGIH have OELs in addition to those listed in the annotated tables. The annotated tables contain links to the complete OEL lists from Cal/OSHA and NIOSH. TLVs^® and BEI^®s are not publicly available, but can be purchased on ACGIH^®'s website. For the most current OELs and information on notations such as skin absorption, users should consult complete listings and explanations from Cal/OSHA, NIOSH, and ACGIH. Each of the alternative lists of exposure limits is accompanied by extensive explanatory language on their source websites. These include averaging periods, size selective measures and similar information. In particular, ACGIH^® provides an explanation of the use of TLVs^® and access to documentation. For more information and documentation, consult with these organizations. See more from topic source: https://www.osha.gov/html/a-z-index.html