Chemicals involved in the manufacture of illegal drugs can usually be accessed by criminals in the following industries: 1. **Chemical industry**: Chemical industry practitioners may be exposed to various chemical raw materials and reagents that may be used in the synthesis of illegal drugs. 2. **Pharmaceutical industry**: Although the raw materials and processes of the pharmaceutical industry are strictly regulated, there is still a risk that some practitioners may illegally obtain or divert drugs or their precursor chemicals. 3. **Agricultural chemical industry**: Some chemicals used in this industry may be used to synthesize or produce illegal drugs. 4. **Laboratory supply industry**: Companies that provide chemicals to various research, school or commercial laboratories may also have employees exposed to chemicals that can be used in drug manufacturing. 5. **Cleaning product manufacturing**: Some chemicals used to produce cleaning agents may also be used in illegal production in an improper manner. 6. **Logistics and transportation industry**: Practitioners involved in the transportation of chemicals may have the opportunity to come into contact with or identify abnormal transportation activities. It should be noted that each industry usually has strict legal and regulatory requirements, and illegal activities often involve illegal operations by a few individuals. Enterprises and industry practitioners should strengthen compliance training and risk awareness, and improve monitoring measures to prevent chemicals from flowing into illegal channels.