Chemical Sampling Information
	Carbon Monoxide (by COHb)
Quick Links General Description Exposure Limits Health Factors Monitoring Search    [use word(s)/phrase ] Table of Contents By Name A B C D E F G H I J K L M N O P Q R S T U V W X Y Z By CAS Number General Description Synonyms: CO; Diesel Exhaust Component; Flue Gas, Monoxide OSHA IMIS Code Number: C730 IMIS Name History: Carboxyhemoglobin prior to 5/20/05 Chemical Abstracts Service (CAS) Registry Number: 630-08-0 NIOSH, Registry of Toxic Effects (RTECS) Identification Number: FG3500000 Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 1016 119 [27 KB, PDF]; 9202 168 [27 KB, PDF] (cryogenic liquid) NIOSH Pocket Guide to Chemical Hazards, Carbon Monoxide: chemical description, physical properties, potentially hazardous incompatibilities, and more Exposure Limits OSHA Permissible Exposure Limit (PEL) for General Industry: 29 CFR 1910.1000 Z-1 Table -- 50 ppm, 55 mg/m3 TWA OSHA Permissible Exposure Limit (PEL) for Construction Industry: 29 CFR 1926.55 Appendix A -- 50 ppm, 55 mg/m3 TWA OSHA Permissible Exposure Limit (PEL) for Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 50 ppm, 55 mg/m3 TWA American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 25 ppm, 29 mg/m3 TWA; BEI National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 35 ppm, 40 mg/m3 TWA; 200 ppm, 229 mg/m3 Ceiling Health Factors NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 1,200 ppm Potential symptoms: Headaches; tachypnea; nausea; weakness, dizziness, confusion, halucinations; cyanosis; depressed, ST segment of electrocardiogram; angina; syncope Health Effects: Asphyxiation, Chemical anoxia Affected organs: CVS, lungs, blood, CNS NIOSH/OSHA/DOE Health Guideline: Carbon Monoxide Monitoring Methods used by OSHA CO-Poisoning Incident Investigation Method: Calculation Performed and Peer-Reviewed by Trained SLTC Staff: method reference: Carbon monoxide (CO) exposure is determined by calculation based on carboxyhemoglobin (COHb) measurements provided by medical professionals as described below. OSHA uses a modified Coburn, Forster, Kane (CFK) Calculation. The documented SLTC modifications (printed in the supplemental report that accompanies the results) use a more accurate version of the CFK equation than the closed-form [e.g., ppm CO = f(x,y,z,…)] version used in the 1972 NIOSH criteria document for the purpose of calculating the 8-hr TWA ppm REL that would result in a 5% COHb level [U.S. Department of Health, Education, and Welfare: Criteria for a Recommended Standard - Occupational Exposure to Carbon Monoxide. Pub. No. HSM 73-11000. NIOSH, Cincinnati, OH (1972).] Poisoning cases generally involve levels above 5% COHb. The more accurate version is necessary to address the full range of % COHb levels found in poisoning cases and requires an iterative computer program. Additional refinements to the calculation address, gender, CO washout after exposure, oxygen administration, the effect of first and second-hand tobacco smoke, elevation, finer gradations of activity levels, and body size. The calculation also provides an incident-specific sampling and analytical error (SAE) based on a Monte-Carlo approach designed to deal with the uncertainties in the data. The calculation is performed at SLTC and the results are critically assessed for correctness by SLTC experts prior to reporting. SLTC experts are available to assist the CSHO in acquiring the data and in interpreting the results. method classification: Validated blood-gas device: COHb analysis is a routine measurement during the medical response to a suspected CO-poisoning incident or from an autopsy after a suspected CO-poisoning incident. As a result, the COHb analysis is performed using a blood-gas instrument that is part of a quality system. The COHb analysis is not performed at SLTC. manufacturer: Varies model/type: Varies sampling information: The exposure incident is documented on a worksheet. Personal information is used to assess the affect of any tobacco smoking behavior (before, during and after the exposure), blood volume, and activity levels (during and after the exposure). A worksheet is REQUIRED and is available on OSHA's Intranet or by calling SLTC's Physical Measurements Team Leader for instructions. The CSHO may supplement the worksheet with additional information such as the results from the emergency responder's or CSHO's area sampling of the worksite. post-exposure delay to sampling: Preferably less than about 6 hours for living persons, longer delays may result in significantly higher SAEs or the inability to distinguish an overexposure from the baseline for the individual. upper measurement limit: 200,000 ppm detection limit: Dependent on details of exposure incident sampling and analytical error: Dependent on details of exposure incident Triage: Contact SLTC's Physical Measurements Team Leader in cases where CO poisoning affects more than 4 individuals. The most practical use of resources sometimes requires evaluating the most severely affected employees. Alternate monitoring methods: Yes, see Carbon Monoxide All Trademarks are the property of their respective owners. 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