BrainChildren ChemistryPreview
Open in TheBrain

Bromomethane

Bromomethane, also known as methyl bromide (CH3Br), is a colorless, odorless, nonflammable gas at room temperature. It has been widely used as a fumigant for soil and space fumigation to control pests, including fungi, nematodes, weeds, insects, and rodents in agricultural settings, as well as for the fumigation of food commodities, such as grains[1][5]. Bromomethane is also utilized in the manufacture of other chemicals and as a solvent for extracting oils from nuts, seeds, and wool[5][10]. Despite its effectiveness as a fumigant, bromomethane is a recognized ozone-depleting chemical and has been subject to phase-out requirements under the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer[5].

Physical and Chemical Properties

Health Effects and Safety

Bromomethane is highly toxic and can be absorbed through inhalation and skin contact. Exposure to high concentrations can cause severe respiratory and central nervous system effects, including tremors, seizures, and decline in mental abilities. Chronic exposure may lead to neurological damage, including peripheral neuropathies and visual impairment[3]. It is also capable of causing skin irritation and burns upon contact with the liquid form. Despite its toxicity, bromomethane is not classified as a carcinogen by major health organizations[3][12].

Environmental Impact

Bromomethane contributes to ozone layer depletion. It is readily photolyzed in the atmosphere, releasing bromine radicals, which are more destructive to stratospheric ozone than chlorine[5]. Due to its environmental impact, the production and use of bromomethane have been significantly reduced globally, with exceptions for critical uses as outlined by the Montreal Protocol[9].

Regulation and Phase-out

The Montreal Protocol has mandated the phase-out of bromomethane due to its ozone-depleting properties. Developed countries, including the United States, have implemented reductions in the production and importation of bromomethane, leading to a complete phase-out by 2005, except for critical uses and quarantine and pre-shipment applications[9][5]. Alternatives to bromomethane, including both chemical and non-chemical methods, are being researched and utilized to manage pests previously controlled with bromomethane[9].

Conclusion

Bromomethane has been an effective fumigant for agricultural and quarantine purposes but poses significant health risks and environmental concerns due to its toxicity and ozone-depleting potential. Its use has been largely phased out under international agreements, with ongoing efforts to find and implement safer and environmentally friendly alternatives.

Citations:

[1] https://pubchem.ncbi.nlm.nih.gov/compound/Bromomethane

[2] https://www.atsdr.cdc.gov/toxprofiles/tp27-c4.pdf

[3] https://wwwn.cdc.gov/TSP/MMG/MMGDetails.aspx?mmgid=818&toxid=160

[4] https://wwwn.cdc.gov/TSP/substances/ToxSubstance.aspx?toxid=160

[5] https://en.wikipedia.org/wiki/Bromomethane

[6] https://pubchem.ncbi.nlm.nih.gov/compound/Bromoethane

[7] https://nj.gov/health/eoh/rtkweb/documents/fs/1231.pdf

[8] https://www.atsdr.cdc.gov/toxprofiles/tp27-c5.pdf

[9] https://www.epa.gov/ods-phaseout/methyl-bromide

[10] https://www.chemeurope.com/en/encyclopedia/Bromomethane.html

[11] https://www.osha.gov/chemicaldata/552

[12] https://wwwn.cdc.gov/TSp/ToxFAQs/ToxFAQsDetails.aspx?faqid=821&toxid=160

[13] https://inchem.org/documents/pims/chemical/methbrom.htm

[14] https://www.airgas.com/msds/001035.pdf

[15] https://www.epa.gov/sites/default/files/2016-09/documents/methyl-bromide.pdf

[16] https://dhss.delaware.gov/dhss/dph/files/bromomethanefaq.pdf

[17] https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/bromomethane

[18] https://www.ncbi.nlm.nih.gov/books/NBK201456/

[19] https://www.atsdr.cdc.gov/toxfaqs/tfacts27.pdf

[20] http://npic.orst.edu/factsheets/MBgen.pdf

Attachments