Which of the following is a hazard associated with benzophenone?

Benzophenone is primarily known for being harmful to aquatic life, as it can pose a risk to the environment due to its potential toxicity to organisms in water bodies. It is classified under substances that can have detrimental effects on ecological systems, particularly affecting fish and other aquatic organisms.

The option describing it as "explosive under heat" is not accurate; benzophenone does not exhibit explosive behavior when subjected to heat. Instead, it is more commonly recognized for its various harmful biological effects rather than explosive potential. Thus, being harmful to the environment and aquatic life is indeed an important hazard associated with benzophenone.