The purpose of combining chloropicrin with methyl bromide for fumigation is to ________.

Combining chloropicrin with methyl bromide serves primarily as a safety measure by having chloropicrin act as a warning agent. Chloropicrin has a strong, pungent odor that alerts those nearby to the presence of hazardous gases, including methyl bromide, which is odorless and can be very dangerous when inhaled. This combination ensures that people can evacuate the area or take necessary precautions when they sense the warning agent, thereby improving safety in fumigation operations.

The rationale behind this combination is rooted in the toxicological characteristics of both substances. Methyl bromide is an effective fumigant but poses significant respiratory hazards, making it imperative to have an identifiable warning system in place. By using chloropicrin as a warning agent, the risks associated with accidental exposure can be mitigated to some extent, as it provides an early indication of potential danger.