Consider the following chemical compounds 1. Aluminium phosphide 2. Endosulfan 3. Malathion 4. Methyl bromide Which of these are used as fumigants ?

Fumigants are chemical compounds that exist in a gaseous state at lethal concentrations to kill pests. Aluminium phosphide and Methyl bromide are the primary chemicals used for this purpose. Aluminium phosphide reacts with atmospheric moisture to release phosphine gas, which is a highly effective fumigant for stored grains [t1, t2, t3]. Methyl bromide is another widely used gaseous fumigant, though its use is increasingly restricted due to its ozone-depleting properties [t4, t6]. In contrast, Endosulfan and Malathion are classified as broad-spectrum organochlorine and organophosphate insecticides, respectively. While they are used for pest control via spraying or soil application, they do not function as fumigants (gaseous poisons) in standard agricultural practice. Therefore, only compounds 1 and 4 are correctly identified as fumigants [t1, t5].

Sources

1. [1] https://npponepal.gov.np/progressfiles/Training-Manual-on-AlPH3-Fumigation_1549364287-1701156938.pdf
2. [2] https://www.ams.usda.gov/sites/default/files/media/FumigationHB.pdf
3. [3] https://ppqs.gov.in/sites/default/files/volume-ii_0.pdf
4. [4] https://www.fao.org/4/x5065e/x5065E0g.htm
5. [5] http://www.osha.gov/publications/shib010615
6. [6] https://www.sciencedirect.com/science/article/abs/pii/S0261219421000727