Editing Hydrazine (section)

== Occupational hazards ==
=== Health effects ===
Potential routes of hydrazine exposure include dermal, ocular, inhalation and ingestion.<ref name=":3">{{Cite web |url=https://www.cdc.gov/niosh/docs/81-123/pdfs/0329.pdf |title=Occupational Safety and Health Guideline for Hydrazine—Potential Human Carcinogen |date=1988 |website=[[National Institute for Occupational Safety and Health|NIOSH]]|access-date=23 Nov 2018}}</ref>

Hydrazine exposure can cause skin irritation/contact dermatitis and burning, irritation to the eyes/nose/throat, nausea/vomiting, shortness of breath, pulmonary edema, headache, dizziness, central nervous system depression, lethargy, temporary blindness, seizures and coma. Exposure can also cause organ damage to the liver, kidneys and central nervous system.<ref name=":3" /><ref name=":2">{{Cite web |url=https://www.epa.gov/sites/production/files/2016-09/documents/hydrazine.pdf |title=Hydrazine 302-01-2 |website=[[United States Environmental Protection Agency|US EPA]] |access-date=23 Nov 2018}}</ref> Hydrazine is documented as a strong skin sensitizer with potential for cross-sensitization to hydrazine derivatives following initial exposure.<ref name=":4">{{Cite web |url=http://www.inchem.org/documents/hsg/hsg/hsg056.htm |title=International Programme on Chemical Safety—Health and Safety Guide No. 56—Hydrazine |date=1991 |website=IPCS INCHEM |publisher=[[World Health Organization|WHO]] |location=Geneva |access-date=24 Nov 2018}}</ref> In addition to occupational uses reviewed above, exposure to hydrazine is also possible in small amounts from tobacco smoke.<ref name=":2" />

The official U.S. guidance on hydrazine as a carcinogen is mixed but generally there is recognition of potential cancer-causing effects. The [[National Institute for Occupational Safety and Health|National Institute for Occupational Safety and Health (NIOSH)]] lists it as a "potential occupational carcinogen". The National Toxicology Program (NTP) finds it is "reasonably anticipated to be a human carcinogen". The [[American Conference of Governmental Industrial Hygienists|American Conference of Governmental Industrial Hygienists (ACGIH)]] grades hydrazine as "A3—confirmed animal carcinogen with unknown relevance to humans". The U.S. Environmental Protection Agency (EPA) grades it as "B2—a probable human carcinogen based on animal study evidence".<ref name=":5">{{Cite web |url=https://www.osha.gov/chemicaldata/chemResult.html?recNo=347 |title=Occupational Chemical Database—Hydrazine |website=www.osha.gov |publisher=[[Occupational Safety and Health Administration|OSHA]] |access-date=24 Nov 2018}}</ref>

The International Agency for Research on Cancer (IARC) rates hydrazine as "2A—probably carcinogenic to humans" with a positive association observed between hydrazine exposure and lung cancer.<ref name=":03">{{Cite web |url=https://monographs.iarc.fr/wp-content/uploads/2018/06/mono115-06.pdf |title=Hydrazine |date=Jun 2018 |publisher=[[International Agency for Research on Cancer|IARC]] |access-date=23 Nov 2018 |archive-date=26 November 2020 |archive-url=https://web.archive.org/web/20201126130626/https://monographs.iarc.fr/wp-content/uploads/2018/06/mono115-06.pdf }}</ref> Based on cohort and cross-sectional studies of occupational hydrazine exposure, a committee from the [[National Academy of Sciences|National Academies of Sciences]], Engineering and Medicine concluded that there is suggestive evidence of an association between hydrazine exposure and lung cancer, with insufficient evidence of association with cancer at other sites.<ref>{{Cite book |title=Gulf War and Health: Fuels, Combustion Products, and Propellants |last=Institute of Medicine |publisher=The National Academies Press |year=2005 |isbn=978-0-309-09527-3 |volume=3 |location=Washington, DC |page=347 |chapter=Ch. 9: Hydrazines and Nitric Acid |doi=10.17226/11180 |s2cid=228274601 }}</ref> The [[European Commission]]'s [[Scientific Committee on Occupational Exposure Limit Values|Scientific Committee on Occupational Exposure Limits]] (SCOEL) places hydrazine in carcinogen "group B—a genotoxic carcinogen". The genotoxic mechanism the committee cited references hydrazine's reaction with endogenous formaldehyde and formation of a DNA-methylating agent.<ref>{{Cite web |url=http://ec.europa.eu/social/BlobServlet?docId=6516&langId=en |title=Recommendation from the Scientific Committee on Occupational Exposure Limits for Hydrazine |date=Aug 2010 |website=European Commission |format=PDF|access-date=23 Nov 2018}}</ref>

In the event of a hydrazine exposure-related emergency, [[National Institute for Occupational Safety and Health|NIOSH]] recommends removing contaminated clothing immediately, washing skin with soap and water, and for eye exposure removing contact lenses and flushing eyes with water for at least 15 minutes. [[NIOSH]] also recommends anyone with potential hydrazine exposure to seek medical attention as soon as possible.<ref name=":3" /> There are no specific post-exposure laboratory or medical imaging recommendations, and the medical work-up may depend on the type and severity of symptoms. The [[World Health Organization]] (WHO) recommends potential exposures be treated symptomatically with special attention given to potential lung and liver damage. Past cases of hydrazine exposure have documented success with pyridoxine ([[vitamin B6]]) treatment.<ref name=":4" />

=== Occupational exposure limits ===
* [[National Institute for Occupational Safety and Health|NIOSH]] Recommended Exposure Limit (REL): 0.03 [[Parts-per notation|ppm]] (0.04&nbsp;mg/m<sup>3</sup>) 2-hour ceiling<ref name=":5" />
* [[Occupational Safety and Health Administration|OSHA]] Permissible Exposure Limit (PEL): 1 ppm (1.3&nbsp;mg/m<sup>3</sup>) 8-hour Time Weighted Average<ref name=":5" />
* [[American Conference of Governmental Industrial Hygienists|ACGIH]] Threshold Limit Value (TLV): 0.01 ppm (0.013&nbsp;mg/m<sup>3</sup>) 8-hour Time Weighted Average<ref name=":5" />

The odor threshold for hydrazine is 3.7 ppm, thus if a worker is able to smell an ammonia-like odor then they are likely over the exposure limit. However, this odor threshold varies greatly and should not be used to determine potentially hazardous exposures.<ref name=":12">{{Cite web |url=https://nj.gov/health/eoh/rtkweb/documents/fs/1006.pdf |title=Hazardous Substance Fact Sheet—Hydrazine |date=Nov 2009 |website=New Jersey Department of Public Health |access-date=23 Nov 2018}}</ref>

For aerospace personnel, the [[United States Air Force]] uses an emergency exposure guideline, developed by the [[National Academy of Sciences]] Committee on Toxicology, which is utilized for non-routine exposures of the general public and is called the Short-Term Public Emergency Exposure Guideline (SPEGL). The SPEGL, which does not apply to occupational exposures, is defined as the acceptable peak concentration for unpredicted, single, short-term emergency exposures of the general public and represents rare exposures in a worker's lifetime. For hydrazine the 1-hour SPEGL is 2 ppm, with a 24-hour SPEGL of 0.08 ppm.<ref name=":6">{{Cite web |url=https://webapp1.dlib.indiana.edu/virtual_disk_library/index.cgi/821003/FID177/pubs/af/48/afoshstd48-8/afoshstd48-8.pdf |title=Air Force Occupational Safety and Health (AFOSH) Standard 48-8 |date=1 Sep 1997 |website=[[United States Air Force|USAF]] |access-date=23 Nov 2018}}</ref>

=== Handling and medical surveillance ===
A complete surveillance programme for hydrazine should include systematic analysis of biologic monitoring, medical screening and morbidity/mortality information. The [[Centers for Disease Control and Prevention|CDC]] recommends surveillance summaries and education be provided for supervisors and workers. Pre-placement and periodic medical screening should be conducted with specific focus on potential effects of hydrazine upon functioning of the eyes, skin, liver, kidneys, hematopoietic, nervous and respiratory systems.<ref name=":3" />

Common controls used for hydrazine include process enclosure, local exhaust ventilation and [[personal protective equipment]] (PPE).<ref name=":3" /> Guidelines for hydrazine PPE include non-permeable gloves and clothing, indirect-vent splash resistant goggles, face shield and in some cases a respirator.<ref name=":12" /> The use of respirators for the handling of hydrazine should be the last resort as a method of controlling worker exposure. In cases where respirators are needed, proper respirator selection and a complete respiratory protection program consistent with [[Occupational Safety and Health Administration|OSHA]] guidelines should be implemented.<ref name=":3"/>

For [[United States Air Force|USAF]] personnel, Air Force Occupational Safety and Health (AFOSH) Standard 48-8, Attachment 8 reviews the considerations for occupational exposure to hydrazine in missile, aircraft and spacecraft systems. Specific guidance for exposure response includes mandatory emergency shower and eyewash stations and a process for decontaminating protective clothing. The guidance also assigns responsibilities and requirements for proper PPE, employee training, medical surveillance and emergency response.<ref name=":6" /> USAF bases requiring the use of hydrazine generally have specific base regulations governing local requirements for safe hydrazine use and emergency response.