Threshold limit concentration

Sulfur Polymer Cement. SPC has been proven effective in reducing leach rates of reactive heavy metals to the extent that some wastes can be managed solely as low level waste (LLW). When SPC is combined with mercury and lead oxides (both toxic metals), it interacts chemically to form mercury sulfide, HgS, and lead sulfide, PbS, both of which are insoluble in water. A dried sulfur residue from petroleum refining that contained 600-ppm vanadium (a carcinogen) was chemically modified using dicyclopentadiene and oligomer of cyclopentadiene and used to make SC (58). This material was examined by the California Department of Health Services (Cal EPA) and the leachable level of vanadium had been reduced to 8.3 ppm, well below the soluble threshold limit concentration of 24 ppm (59). 

Threshold limit concentration (TLC) The concentration of an air pollutant allowed in the work space. 

TLC See Capacity, total lung or threshold limit concentration. 

To suggest a threshold-limited concentration of individual synthetic colorants, it was necessary to set up an imaginary concentration of such colorants to be considered as a cut-off concentration set to twice the DL of each synthetic colorant... 

Hazardous Waste Constituents Total threshold limit concentration Restricted Pesticides... 

In California Code of Regulations (CCR) Title 22, the State of California imposes additional requirements for the disposal of waste containing 20 inorganic and 18 organic persistent and bioaccumulative toxic substances (CCR, 1991). Hazardous characteristics of waste streams contaminated with these substances are determined as Total Threshold Limit Concentrations (TTLQ and Soluble Threshold Limit Concentrations (STLC), shown in Appendix 4. 

List of California Toxic Substances, their Soluble Threshold Limit Concentrations and Total Threshold Limit Concentrations... 

STLC denotes Soluble Threshold Limit Concentration. 

CA Total Threshold Limit Concentration Toxic Materials Limits (30-d avg.) 1 mg/kg 0.0039 pg/L CELDS 1994... 

Direct-reading field monitors equipped with chart recorders are also available for monitoring many industrial gases over long periods of time in order that an accurate time-weighted average concentration can be produced. Many manufacturing facilities have permanently installed air contaminant monitors equipped with alarms which sound when the threshold limit concentration is exceeded. 

OSHA = Occupational Safety and Health Administration PEL = permissible exposure limit REL = recommended exposure limit TLV = threshold limit value TTLC = total threshold limit concentration TWA = time-weighted average USC = United States Code... 

In "real-fire" situation experiments, in which commercial CCl, extinguishers were used to extinguish fires contained in closed rooms (28 m capacity), phosgene is said to be generated in lethal concentrations [649b]. At the industrial threshold limit concentration of... 

Cal 1forni a Soluble threshold limit concentration for wastes 0.25 mg/L CELDS 1992... 

The TLVs, as issued by the American Conference of Govemmentai industrial Hygienists, are recommendations and should be used as guidelines for good practices. In spite of the fact that serious injury is not believed likely as a result of exposure to the threshold limit concentrations, the best practice is to maintain concentrations of all atmospheric contaminants as low as is practical. The American Conference of Governmental Industrial Hygienists disclaims liability with respect to the use of TLVs. 

G. Total Threshold Leaching Concentration (TTLC) and Soluble Threshold Limit Concentration (STLC)... 

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