Chlorpyrifos (CAS 2921-88-2) stands as a highly potent organophosphorus insecticide renowned for its exceptional efficacy in eliciting contact, stomach poison, and fumigation effects. Its multifaceted nature renders it indispensable in agricultural and pest control endeavors.

**Chemical and Physical Properties**

Presenting as a white granular crystal with a distinctive pungent odor, Chlorpyrifos boasts a density of 1.398 and a melting point within the range of 42-44°C. Although it exhibits low water solubility, its solubility in organic solvents is notably high.

**Applications**

Chlorpyrifos finds extensive utility as an insecticide across a diverse spectrum of crops, spanning corn, cotton, soybeans, peanuts, sugar beets, fruit trees, and vegetables. Its efficacy extends to the control of a wide array of insects, including corn rootworms, cutworms, aphids, thrips, and root maggots.

Moreover, Chlorpyrifos serves as a valuable asset in domestic pest management initiatives, targeting mosquitoes, flies, cockroaches, and termites. Its application is also prevalent in granaries and livestock operations to combat ectoparasites.

**Safety Considerations**

Despite its efficacy, Chlorpyrifos bears significant toxicity towards bees and aquatic organisms. Adherence to meticulous handling and application practices is imperative to mitigate its environmental impact. The United States Environmental Protection Agency (EPA) has instituted maximum allowable residue limits on various crops and indoor air concentrations.

**Conclusion**

In essence, Chlorpyrifos emerges as a potent and versatile insecticide pivotal in safeguarding crops and addressing household pest infestations. Its distinctive chemical properties coupled with its broad-spectrum activity render it an invaluable component of sustainable pest management strategies.