Editing Permissible exposure limit (section)

== Chemical regulation for permissible exposure limits ==
Permissible Exposure Limits are regulatory limits for chemical hazards in a workplace set by [[Occupational Safety and Health Administration|OSHA]].<ref>{{Cite web |date=2022-12-14 |title=1988 OSHA PEL Project Documentation {{!}} NIOSH |url=https://www.cdc.gov/niosh/pel88/pelstart.html |access-date=2023-11-28 |website=www.cdc.gov |language=en-us}}</ref><ref name=what>{{Cite web |date=2015-07-30 |title=What is the PEL and How Does it Work? |website=Safety Management Group |url=https://safetymanagementgroup.com/blog/what-is-the-pel-and-how-does-it-work/ |access-date=2023-11-28 |language=en-US}}</ref> Organizations may implement stricter guidelines for chemical use and exposure, but OSHA guidelines must be followed at the minimum.<ref name=smr>{{Cite journal |last=Rappaport |first=S. M. |date=May 1993 |title=Threshold limit values, permissible exposure limits, and feasibility: The bases for exposure limits in the United States |url=https://onlinelibrary.wiley.com/doi/10.1002/ajim.4700230502 |journal=American Journal of Industrial Medicine |language=en |volume=23 |issue=5 |pages=683–694 |doi=10.1002/ajim.4700230502 |issn=0271-3586|url-access=subscription }}</ref><ref name=what/> Permissible Exposure Limits are time-weighted average, meaning that a worker may be exposed to higher concentrations of the chemical at different times of the work shift.<ref name=what/><ref>{{Cite web |title=Workplace Exposure Limits |url=https://response.restoration.noaa.gov/oil-and-chemical-spills/chemical-spills/resources/workplace-exposure-limits.html |access-date=2023-11-28 |website=response.restoration.noaa.gov}}</ref>

Many factors contribute in establishing Permissible Exposure Limits. [[Threshold limit value|Threshold Limit Values]] (TLVs), often determined by the [[American Conference of Governmental Industrial Hygienists]] (ACGHI), is a key component in determining the PEL.<ref name=smr/><ref name=what/> Other things that contribute to determining the PEL are toxicity and particle size.<ref name=what/>

PELs for chemicals are measured in mg/M<sup>3</sup> (milligrams per cubic meter).<ref name=":2" /> Mg/M<sup>3</sup> is used to measure pollutant’s mass in the air.<ref>{{Cite web |title=What is Milligram Per Cubic Meter (Mg/M3)? - Definition from Safeopedia |url=http://www.safeopedia.com/definition/90/milligram-per-cubic-meter-mgm3 |access-date=2023-11-28 |website=safeopedia.com |language=en}}</ref> PELs compliance is monitored through direct reading measurement tools, various sampling methods, and measuring biological markers in workers.<ref name=":0">{{Cite web |date=November 6, 2023 |title=Direct Reading Instruments |url=https://www.osha.gov/direct-reading-instruments |access-date=November 6, 2023 |website=osha.gov/direct-reading-instruments}}</ref><ref name=":1">{{Cite journal |last=Tustin |first=Aaron W. |last2=Cannon |first2=Dawn L. |date=February 2022 |title=Analysis of biomonitoring data to assess employer compliance with OSHA's permissible exposure limits for air contaminants |url=https://onlinelibrary.wiley.com/doi/10.1002/ajim.23317 |journal=American Journal of Industrial Medicine |language=en |volume=65 |issue=2 |pages=81–91 |doi=10.1002/ajim.23317 |issn=0271-3586|url-access=subscription }}</ref>  Sampling for biological markers may include sampling urine and blood.<ref name=":1" /> Direct measurement tools, such as Q-Trak, and indirect measurement tools such as [[Gas chromatography–mass spectrometry|gas chromatography]] can be used for air sampling.<ref name=":0" />