Technical Basis
A review of available sources did not identify acute toxicity data or exposure limits for mercurous chloride. Instead, exposure limits for aryl and inorganic mercury compounds (inorganic mercury, CASRN: 7439-97-6; ceiling limits, TWAs, ERPG-3/ERPG-2, and IDLH) were evaluated for TEEL development. Data sources were selected according to the hierarchy listed in Table 3.1. The mercury aryl and inorganic compounds ERPG-3 and ERPG-2 were selected as the TEEL-3 and TEEL-2, respectively. The mercury TLV-TWA was selected as the TEEL-1 basis and a compound adjustment factor was applied (Section 3.2.2).
• TEEL-1 = MW-adjusted TLV-TWA (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.025 mg/m3) x 3
• TEEL-2 = ERPG-2 (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.25 ppm)
• TEEL-3 = ERPG-3 (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.5 ppm)
This review generated TEEL-3 and TEEL-2 values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was the mercury 1990 IDLH (CASRN: 7439-97-6) and the Rev. 29A TEEL-2 basis was a mercury PEL-C; compound adjustment factors were applied to both limits. The current TEEL-3 and TEEL-2 are unadjusted ERPGs for mercury aryl and inorganic compounds (CASRN: 7439-97-6), a higher priority source (Section 1). The Rev. 29A and current TEEL-1 values, methodology, and source are consistent.
References
Chemical information: https://pubchem.ncbi.nlm.nih.gov/compound/Chloromercury
https://www.fishersci.com/store/msds?partNumber=M159100&productDescription=MERCUROUS+CHLOR+CERT+ACS+100G&vendorId=VN00033897&countryCode=US&language=en
Mercury, aryl and inorganic compounds exposure limits: https://www.osha.gov/chemicaldata/504
Mercury compounds [except (organo) alkyls], as Hg IDLH: https://www.cdc.gov/niosh/idlh/7439976.html