Methyl bromide is a colorless and odorless gas that is generally not flammable but which can produce poisonous gases when exposed to fire. It is produced from bromide salts, which occur naturally. The gas can be converted to a liquid when it is placed under a sufficient amount of pressure. This substance has been used to control pests such as insects, rodents, and weeds. It has also been used to protect crops both before and after harvesting.
Methyl bromide was widely used internationally by the agricultural industry prior to phase-out requirements issued by the Montreal Protocol for Ozone Depleting Substances. This treaty was adopted in 1987 to eliminate the use of substances that destroy the ozone layer. Methyl bromide is believed to significantly act in this regard.
In some instances, the substance was used to sterilize the soil. This was usually done by injecting methyl bromide into the soil before the seeds were planted. The purpose of doing this was to kill harmful organisms in the soil. Crops protected in this manner include tomatoes, grapes, and strawberries.
This substance has also been used to treat foods after they were harvested. In these cases, foods such as cherries and nuts were exposed to methyl bromide in an enclosed setting. This was done for quarantine purposes and to fulfill trade regulations.
Although the use of the substance has been vastly reduced by the Montreal Protocol for Ozone Depleting Substances, it has not been completely eliminated. In the United States, for example, exemptions allow for its use in critical instances and when there is a need for quarantine.
Methyl bromide is not only a risk to the environment but it can also have adverse effects on humans. When the substance is inhaled it can cause coughing, breathing problems, or buildup of fluid in the lungs. If the exposure is more severe, a series of other negative effects could occur. These include brain damage or failure of the central nervous system. A person affected by the substance could experience numbness of the limbs, trouble with coordination, and personality changes.
Even contact with the skin can be dangerous. People who deal with this substance should wear protective gear. If this substance comes into contact with skin or any items a person is wearing, it is advisable to remove the soiled items and immediately clean the skin with soap and water.