Editing Formic acid (section)

==Safety==
Formic acid has low toxicity (hence its use as a food additive), with an {{LD50}} of 1.8{{nbsp}}g/kg (tested orally on mice). The concentrated acid is corrosive to the skin.<ref name=Ullmann_2009/>

Formic acid is readily metabolized and eliminated by the body. Nonetheless, it has specific [[toxic]] effects; the formic acid and [[formaldehyde]] produced as metabolites of [[methanol]] are responsible for the [[optic nerve]] damage, causing blindness, seen in [[methanol poisoning]].<ref>{{cite journal |doi=10.1136/jnnp.72.4.423 |pmid=11909893 |pmc=1737836 |year=2002 |last1=Sadun |first1=A. A |title=Mitochondrial optic neuropathies |journal=Journal of Neurology, Neurosurgery, and Psychiatry |volume=72 |issue=4 |pages=423–5 }}</ref> Some chronic effects of formic acid exposure have been documented. Some experiments on bacterial species have demonstrated it to be a [[mutagen]].<ref name="osha.gov">{{cite web|url=http://www.osha.gov/SLTC/healthguidelines/formicacid/recognition.html|title=Occupational Safety and Health Guideline for Formic Acid|publisher=OSHA|access-date=28 May 2011|archive-date=20 September 2011|archive-url=https://web.archive.org/web/20110920200807/http://www.osha.gov/SLTC/healthguidelines/formicacid/recognition.html|url-status=dead}}</ref> Chronic exposure in humans may cause kidney damage.<ref name="osha.gov"/> Another possible effect of chronic exposure is development of a skin [[allergy]] that manifests upon re-exposure to the chemical.

Concentrated formic acid slowly decomposes to carbon monoxide and water, leading to pressure buildup in the containing vessel. For this reason, 98% formic acid is shipped in plastic bottles with self-venting caps.{{cn|date=June 2024}}

The hazards of solutions of formic acid depend on the concentration. The following table lists the [[Globally Harmonized System of Classification and Labelling of Chemicals]] for formic acid solutions:{{citation needed|date=October 2021}}

{| class = "wikitable"
|-
! [[Concentration]] ([[weight percent]])
! Pictogram
! [[List of H-phrases|H-Phrases]]
|-
| 2–10%
| {{GHS07}}
| {{H-phrases|315}}
|-
| 10–90%
| {{GHS05}}
| {{H-phrases|313}}
|-
| >90%
| {{GHS05}}
| {{H-phrases|314}}
|}

Formic acid in 85% concentration is flammable, and diluted formic acid is on the U.S. Food and Drug Administration list of food additives.<ref>{{CodeFedReg|21|186|1316}}, {{CodeFedReg|21|172|515}}</ref> The principal danger from formic acid is from skin or eye contact with the concentrated liquid or vapors. The U.S. [[Occupational Safety and Health Administration|OSHA]] Permissible Exposure Level ([[Permissible exposure limit|PEL]]) of formic acid vapor in the work environment is 5 [[parts per million]] (ppm) of air.<ref>{{Cite web |title=CDC - NIOSH Pocket Guide to Chemical Hazards - Formic acid |url=https://www.cdc.gov/niosh/npg/npgd0296.html |access-date=2024-11-01 |website=www.cdc.gov}}</ref>