Many gases have toxic properties, which are often assessed using the LC50 (median lethal concentration) measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 (may be fatal) or 3 (may cause serious or permanent injury), and/or exposure limits (TLV, TWA or STEL) determined by the ACGIH professional association. Some, but by no means all, toxic gases are detectable by odor, which can serve as a warning. Among the best known toxic gases are carbon monoxide, chlorine, nitrogen dioxide and phosgene.
Definition
- Toxic: a chemical that has a median lethal concentration (LC50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats weighing between 200 and 300 grams each.[1][2]
- Highly Toxic: a gas that has a LC50 in air of 200 ppm or less.[2]
- NFPA 704: Materials that, under emergency conditions, can cause serious or permanent injury are given a Health Hazard rating of 3. Their acute inhalation toxicity corresponds to those vapors or gases having LC50 values greater than 1,000 ppm but less than or equal to 3,000 ppm. Materials that, under emergency conditions, can be lethal are given a Health Hazard rating of 4. Their acute inhalation toxicity corresponds to those vapors or gases having LC50 values less than or equal to 1,000 ppm.
List
See also
Notes
- ^ a b Decomposes in gaseous form.
- ^ Explodes in gaseous form.
References
- ^ "California Fire Code California Code of Regulations,Title 24, Part 9, Chapter 2 - Definitions" (PDF).
- ^ a b "Environmental Health and Radiation Safety Department at the University of Pennsylvania".
- ^ "Chemical Name Search". webbook.nist.gov. Retrieved 2021-11-10.
- ^ a b "CDC - NIOSH Pocket Guide to Chemical Hazards - Arsenic (inorganic compounds, as As)". www.cdc.gov. Retrieved 2021-11-10.
- ^ "Principles for the safe handling and distribution of highly toxic gases and mixtures" (PDF). Asia Industrial Gases Association. 2011-07-16. AIGA 026/06. Archived from the original (PDF) on 2011-07-16. Retrieved 2021-09-22.
- ^ "1988 OSHA PEL Project - Boron Tribromide | NIOSH | CDC". www.cdc.gov. 2020-02-25. Retrieved 2021-11-10.
- ^ PubChem. "Boron trichloride". pubchem.ncbi.nlm.nih.gov. Retrieved 2021-11-10.
- ^ a b "Boron Tribromide". Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 17. 2014. doi:10.17226/18796. ISBN 978-0-309-30476-4.
- ^ Methyl bromide - OECD HPVMETHYL BROMIDE CAS N°: 74-83-9
- ^ Levin, B. C.; Paabo, M.; Gurman, J. L.; Harris, S. E.; Braun, E. (1987-12-01). "Toxicological interactions between carbon monoxide and carbon dioxide". Toxicology. 47 (1–2): 135–164. doi:10.1016/0300-483x(87)90165-x. ISSN 0300-483X. PMID 3120355.
- ^ Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 6 (PDF). Environmental Protection Agency. 2007. ISBN 978-0-309-11214-7.
- ^ "Phosphorus(V) fluoride Safety Data Sheet". ThermoFisher Scientific. January 6, 2023.
- ^ "Silicon Tetrachloride Hazardous Substance Fact Sheet" (PDF). New Jersey Department of Health. October 2010.
- ^ "Stibine Hazardous Substance Fact Sheet" (PDF). New Jersey Department of Health and Senior Services. August 2001.
- ^ a b "Sulfur Tetrafluoride Safety Data Sheet" (PDF). Airgas.
- ^ "Tungsten Hexafluoride Safety Data Sheet" (PDF). Airgas.
External links
- OSHA Limits for Air Contaminants
- OSHA Permissible Exposure Limits
- California Department of Industrial Relations Permissible Exposure Limits for Chemicals
