CWEA Laboratory Analyst Grade 3 Certification
Exam
Full Practice Exam – 100+ Questions with Answers
and Rationales 2026
SECTION 1: LABORATORY SAFETY (Questions 1–12)
1. Which piece of personal protective equipment (PPE) is essential when handling corrosive chemicals in
the laboratory?
A. Safety glasses only
B. Nitrile gloves and safety goggles
C. Cotton lab coat only
D. Steel-toed boots
Answer: B
Rationale: When handling corrosive chemicals, chemical-resistant gloves (such as nitrile) and safety
goggles or a face shield are essential to protect against splashes and burns. Safety glasses alone do not
provide sufficient splash protection. A lab coat provides additional protection but gloves and goggles are
the minimum essential PPE.
2. What information is found on a Safety Data Sheet (SDS)?
A. Only the chemical name and formula
,B. Physical and chemical properties, health hazards, first aid measures, and handling precautions
C. The purchase price of the chemical
D. The name of the manufacturer only
Answer: B
Rationale: An SDS provides comprehensive information about a chemical substance, including physical
and chemical properties, health hazards, first aid measures, handling and storage precautions, exposure
controls, and disposal considerations. This information is critical for laboratory safety and regulatory
compliance.
3. What is the primary purpose of a fume hood in the laboratory?
A. To provide additional storage space
B. To contain and exhaust hazardous vapors, gases, and fumes away from the analyst
C. To keep samples at a constant temperature
D. To prevent contamination of reagents
Answer: B
Rationale: Fume hoods are engineering controls designed to protect laboratory personnel by containing
and exhausting hazardous airborne contaminants. They are essential when working with volatile or toxic
chemicals.
4. Which of the following is an example of an engineering control for laboratory safety?
A. Wearing safety goggles
B. Using a fume hood
C. Reading the SDS
D. Following standard operating procedures
,Answer: B
Rationale: Engineering controls are physical modifications to the workplace that reduce hazards—such
as fume hoods, biosafety cabinets, and ventilation systems. PPE (safety goggles) is a personal control,
while SDS review and SOPs are administrative controls.
5. When is it appropriate to eat or drink in a laboratory?
A. During lunch breaks at the laboratory bench
B. Only in designated areas outside the laboratory work area
C. When working with non-toxic chemicals
D. Never, under any circumstances
Answer: B
Rationale: Eating, drinking, chewing gum, and applying cosmetics are prohibited in laboratory work
areas to prevent contamination and accidental ingestion of hazardous materials. Designated areas
outside the laboratory should be used for these activities.
6. What is the proper procedure for disposing of sharps (needles, broken glass) in the laboratory?
A. Place in regular trash bin
B. Place in a puncture-resistant container clearly labeled as sharps waste
C. Rinse and reuse
D. Place in a cardboard box
Answer: B
, Rationale: Sharps must be disposed of in puncture-resistant, leak-proof containers that are clearly
labeled for sharps waste. This protects waste handlers and prevents injury and potential exposure to
biohazards.
7. What does the acronym "SDS" stand for in laboratory safety?
A. Standard Dilution Solution
B. Safety Data Sheet
C. Sample Delivery System
D. Standard Deviation Score
Answer: B
Rationale: SDS stands for Safety Data Sheet, formerly known as Material Safety Data Sheet (MSDS). It
provides detailed information about chemical hazards, handling, and emergency measures.
8. Which of the following is the correct response if a chemical splash occurs in a laboratory worker's
eyes?
A. Wipe eyes with a clean cloth
B. Flush eyes immediately with water at the eyewash station for at least 15 minutes
C. Apply eye drops
D. Wait to see if symptoms develop
Answer: B
Rationale: The immediate response to eye exposure is to flush the eyes with water at an eyewash
station for at least 15 minutes. This dilutes and removes the chemical, minimizing injury.
9. What is the primary hazard associated with confined space entry during wastewater sampling?
Exam
Full Practice Exam – 100+ Questions with Answers
and Rationales 2026
SECTION 1: LABORATORY SAFETY (Questions 1–12)
1. Which piece of personal protective equipment (PPE) is essential when handling corrosive chemicals in
the laboratory?
A. Safety glasses only
B. Nitrile gloves and safety goggles
C. Cotton lab coat only
D. Steel-toed boots
Answer: B
Rationale: When handling corrosive chemicals, chemical-resistant gloves (such as nitrile) and safety
goggles or a face shield are essential to protect against splashes and burns. Safety glasses alone do not
provide sufficient splash protection. A lab coat provides additional protection but gloves and goggles are
the minimum essential PPE.
2. What information is found on a Safety Data Sheet (SDS)?
A. Only the chemical name and formula
,B. Physical and chemical properties, health hazards, first aid measures, and handling precautions
C. The purchase price of the chemical
D. The name of the manufacturer only
Answer: B
Rationale: An SDS provides comprehensive information about a chemical substance, including physical
and chemical properties, health hazards, first aid measures, handling and storage precautions, exposure
controls, and disposal considerations. This information is critical for laboratory safety and regulatory
compliance.
3. What is the primary purpose of a fume hood in the laboratory?
A. To provide additional storage space
B. To contain and exhaust hazardous vapors, gases, and fumes away from the analyst
C. To keep samples at a constant temperature
D. To prevent contamination of reagents
Answer: B
Rationale: Fume hoods are engineering controls designed to protect laboratory personnel by containing
and exhausting hazardous airborne contaminants. They are essential when working with volatile or toxic
chemicals.
4. Which of the following is an example of an engineering control for laboratory safety?
A. Wearing safety goggles
B. Using a fume hood
C. Reading the SDS
D. Following standard operating procedures
,Answer: B
Rationale: Engineering controls are physical modifications to the workplace that reduce hazards—such
as fume hoods, biosafety cabinets, and ventilation systems. PPE (safety goggles) is a personal control,
while SDS review and SOPs are administrative controls.
5. When is it appropriate to eat or drink in a laboratory?
A. During lunch breaks at the laboratory bench
B. Only in designated areas outside the laboratory work area
C. When working with non-toxic chemicals
D. Never, under any circumstances
Answer: B
Rationale: Eating, drinking, chewing gum, and applying cosmetics are prohibited in laboratory work
areas to prevent contamination and accidental ingestion of hazardous materials. Designated areas
outside the laboratory should be used for these activities.
6. What is the proper procedure for disposing of sharps (needles, broken glass) in the laboratory?
A. Place in regular trash bin
B. Place in a puncture-resistant container clearly labeled as sharps waste
C. Rinse and reuse
D. Place in a cardboard box
Answer: B
, Rationale: Sharps must be disposed of in puncture-resistant, leak-proof containers that are clearly
labeled for sharps waste. This protects waste handlers and prevents injury and potential exposure to
biohazards.
7. What does the acronym "SDS" stand for in laboratory safety?
A. Standard Dilution Solution
B. Safety Data Sheet
C. Sample Delivery System
D. Standard Deviation Score
Answer: B
Rationale: SDS stands for Safety Data Sheet, formerly known as Material Safety Data Sheet (MSDS). It
provides detailed information about chemical hazards, handling, and emergency measures.
8. Which of the following is the correct response if a chemical splash occurs in a laboratory worker's
eyes?
A. Wipe eyes with a clean cloth
B. Flush eyes immediately with water at the eyewash station for at least 15 minutes
C. Apply eye drops
D. Wait to see if symptoms develop
Answer: B
Rationale: The immediate response to eye exposure is to flush the eyes with water at an eyewash
station for at least 15 minutes. This dilutes and removes the chemical, minimizing injury.
9. What is the primary hazard associated with confined space entry during wastewater sampling?
