Which of the following statements about pyrethrin is not supported by the material?

• A. It quickly kills fleas
• B. It is biodegradable
• C. It does not build up in the bloodstream
• D. It is illegal to use on dogs

Answer: (D)

Pyrethrin’s safety and regulatory status for dogs is what this item asks you to connect. It quickly kills fleas, producing fast relief from infestation. It is biodegradable, so it breaks down in the environment rather than persisting as a pollutant. It does not build up in the bloodstream because it is only lightly absorbed systemically and is rapidly metabolized and excreted. The statement about it being illegal to use on dogs is not supported, since pyrethrin-based products are commonly approved and used on dogs when directions are followed (with the usual safety caveats, such as not using dog formulations on cats).