1.2.1 Disposal of Waste (Q&A)

Short Answer Questions

1. What is the purpose of proper waste disposal in the laboratory?
   Answer
   Proper waste disposal prevents environmental contamination, reduces personal injury risks, and maintains laboratory safety.
2. What types of liquid waste can be disposed of in the sink?
   Answer
   Acids and alkalis with a pH between 5 and 9, low-concentration solutions, neutral non-hazardous materials (e.g., glucose solutions), and non-corrosive substances.
3. What is the pH range of acids and alkalis that can be safely disposed of in the sink?
   Answer
   Between pH 5 and 9.
4. Name two types of substances that cannot be disposed of in the sink.
   Answer
   Toxic substances, organic solvents (e.g., alcohol, benzene), strong acids or alkalis, heavy metals, radioactive substances, and volatile materials.
5. Give two examples of organic solvents that cannot be poured into the sink.
   Answer
   Alcohol and chloroform.
6. Why should heavy metals not be disposed of in the sink?
   Answer
   Heavy metals like mercury and lead are toxic and can cause environmental contamination.
7. What should be done if a mercury spill occurs in the lab?
   Answer
   Notify the teacher or lab assistant, sprinkle sulphur powder on the spill, and contact the relevant authorities for proper disposal.
8. What is biological waste?
   Answer
   Biological waste includes blood, tissues, organs, and animal carcasses that require special disposal methods.
9. Name the four categories of biological waste.
   Answer
   Category A (sharp objects), Category B (non-sharp solids), Category C (organs and animal carcasses), Category D (liquids like blood and serum).
10. How should sharp biological waste be disposed of?
    Answer
    Sharp waste should be placed in designated containers to prevent injuries.
11. What is the proper method for disposing of non-sharp biological waste?
    Answer
    Non-sharp contaminated waste should be placed in biohazard bags and autoclaved before disposal.
12. How are liquid biological wastes, such as blood, usually disposed of?
    Answer
    Liquid biological waste is disinfected and then disposed of via the sink or toilet.
13. What should be done immediately after a chemical spill in the laboratory?
    Answer
    Notify the teacher or lab assistant and isolate the spill area.
14. Why is it important to use materials like sand to absorb chemical spills?
    Answer
    Sand helps to absorb the chemical and prevent further spreading.
15. Who should dispose of chemical waste in a laboratory?
    Answer
    Trained personnel should handle and dispose of chemical waste safely.
16. Why must different types of waste be stored in separate containers before disposal?
    Answer
    To prevent hazardous reactions and ensure proper waste management.
17. How can waste disposal help maintain laboratory safety?
    Answer
    Proper disposal prevents contamination, reduces health hazards, and keeps the environment safe.
18. What safety document should be consulted for specific chemical disposal instructions?
    Answer
    The Safety Data Sheet (SDS).
19. What type of PPE should be worn when handling waste?
    Answer
    Gloves, safety goggles, lab coats, and face masks.
20. Why should waste containers be properly labelled?
    Answer
    To prevent accidental exposure and ensure correct disposal methods.

Explanation Questions

1. Why is it important to properly dispose of chemical and biological waste?
   Answer
   Proper disposal prevents environmental pollution, reduces health hazards, and maintains lab safety.
2. Explain why strong acids and alkalis cannot be disposed of in the sink.
   Answer
   Strong acids and alkalis (pH <5 or >9) can corrode pipes and cause harmful chemical reactions.
3. How does biological waste management differ from chemical waste management?
   Answer
   Biological waste requires sterilisation (e.g., autoclaving), while chemical waste must be neutralised or stored safely.
4. Describe the correct response to a chemical spill.
   Answer
   Notify authorities, isolate the spill, absorb it using sand, and dispose of it safely.
5. Why should radioactive substances never be poured into the sink?
   Answer
   Radioactive substances can cause long-term environmental and health hazards.
6. Explain the importance of training on waste management in laboratories.
   Answer
   Training ensures lab personnel follow proper disposal methods and safety guidelines.
7. What risks are associated with improper waste disposal?
   Answer
   Environmental pollution, toxic exposure, contamination, and legal consequences.
8. Why must sharp waste be placed in designated containers?
   Answer
   To prevent injuries and contamination.
9. What role does PPE play in waste handling?
   Answer
   PPE protects workers from hazardous exposure during waste disposal.
10. Why should waste containers be regularly checked and replaced?
    Answer
    To prevent leaks, contamination, and overfilling.