• How is the most important of the dangerous chemical substances or chemicals. The impact of human and environmental health and the symptoms that may occur from the use of, and the use of unlawful methods.
• The most significant aspect is the danger of chemical or chemicals. The impact on human health and the environment. Symptoms that may occur from the use and misuse of ways.
- the most important of the hazardous chemicals or chemicals. The impact on human health and the environment. Signs and symptoms that may arise from the use of, and using the wrong way.