OIT Chemical Handling and Storage 1 — Questions and Answers
Question 1: What document must be available to workers for every hazardous chemical used at a water treatment facility?
- Material Safety Data Sheet (MSDS) or Safety Data Sheet (SDS) (Correct answer)
- Chemical purchase invoice
- Operator license certificate
- State permit application
Correct answer: Material Safety Data Sheet (MSDS) or Safety Data Sheet (SDS)
OSHA's Hazard Communication Standard requires Safety Data Sheets (SDS, formerly MSDS) to be accessible for every hazardous chemical at the workplace.
Question 2: Chlorine gas cylinders stored in a treatment facility should be kept at a temperature below what level to prevent excessive pressure buildup?
- 130°F (54°C)
- 100°F (38°C) (Correct answer)
- 70°F (21°C)
- 50°F (10°C)
Correct answer: 100°F (38°C)
Chlorine cylinders should not be stored above 100°F (38°C) because higher temperatures increase vapor pressure and risk of cylinder failure or leaks.
Question 3: When mixing chemicals at a water treatment plant, which of the following is the correct and safe practice?
- Add water to acid to reduce splashing
- Add acid to water to dissipate heat safely (Correct answer)
- Mix chemicals together then add water
- Heat the solution first then add chemicals
Correct answer: Add acid to water to dissipate heat safely
Always add acid to water (never water to acid) to safely dissipate the heat generated and prevent a violent exothermic reaction.
Question 4: Which type of Personal Protective Equipment (PPE) is required when handling concentrated sodium hypochlorite solution?
- Leather gloves and safety glasses only
- Chemical-resistant gloves, face shield, and apron (Correct answer)
- Standard cotton gloves and goggles
- Hard hat and steel-toed boots only
Correct answer: Chemical-resistant gloves, face shield, and apron
Concentrated sodium hypochlorite is corrosive; chemical-resistant gloves, a face shield, and an apron protect against splashes to skin and eyes.
Question 5: How should incompatible chemicals such as chlorine and ammonia be stored at a treatment facility?
- In the same room with a ventilation fan running
- In separate, well-ventilated storage areas with secondary containment (Correct answer)
- In the same secondary containment bin to save space
- Together if the total quantity is under 50 pounds
Correct answer: In separate, well-ventilated storage areas with secondary containment
Incompatible chemicals must be stored separately with secondary containment to prevent accidental mixing, which could produce toxic gases like chloramines.
Question 6: Secondary containment for chemical storage at water treatment facilities is designed to hold at least what percentage of the largest container's volume?
- 50%
- 75%
- 100% (Correct answer)
- 125%
Correct answer: 100%
Secondary containment must hold 100% of the largest single container's volume to capture a full spill and prevent environmental contamination.
Question 7: What is the first action an operator should take upon discovering a chlorine gas leak in the chemical feed room?
- Attempt to tighten the leaking valve immediately
- Evacuate the area and alert others while avoiding breathing the gas (Correct answer)
- Open all windows to dilute the gas concentration
- Pour water over the cylinder to neutralize the leak
Correct answer: Evacuate the area and alert others while avoiding breathing the gas
The immediate priority is evacuation and alerting others; entering a chlorine gas environment without a SCBA is life-threatening.
OIT Chemical Handling and Storage 1
What document must be available to workers for every hazardous chemical used at a water treatment facility?