CWEA WASTEWATER LABORATORY ANALYST CERTIFICATION: NEWLY
UPDATED COLLECTION OF EXAM QUESTIONS AND VERIFIED ANSWERS
1. Q: What is the primary purpose of a safety shower in a wastewater
laboratory? ANSWER To provide immediate decontamination for personnel
exposed to hazardous chemicals or biological materials on their body or
clothing.
2. Q: How long should an eyewash station be activated when chemicals
splash into the eyes? ANSWER Minimum of 15 minutes of continuous
flushing while seeking medical attention.
3. Q: What does MSDS stand for (older term) and what has it been
replaced with? ANSWER Material Safety Data Sheet, replaced by SDS
(Safety Data Sheet) under GHS (Globally Harmonized System).
4. Q: What type of fire extinguisher should be used for electrical fires?
ANSWER Class C fire extinguisher (or ABC multipurpose extinguisher).
5. Q: What is the maximum allowable noise level for 8-hour exposure
according to OSHA? ANSWER 90 decibels (dBA) for 8-hour time-weighted
average.
6. Q: What color are oxidizer warning labels? ANSWER Yellow with black
text and symbol.
7. Q: What is the purpose of a fume hood in a laboratory? ANSWER To
protect laboratory personnel from inhaling toxic, offensive, or flammable
vapors by drawing contaminated air away from the work area.
8. Q: What is the minimum face velocity for a properly functioning fume
hood? ANSWER Typically 80-120 feet per minute (fpm), with 100 fpm being
ideal.
9. Q: What does PPE stand for? ANSWER Personal Protective Equipment.
10. Q: When should safety glasses be worn in the laboratory? ANSWER At
all times when in the laboratory, regardless of whether you are actively
performing procedures.
,11. Q: What is the proper procedure for diluting concentrated acids?
ANSWER Always add acid to water, never water to acid (remember: "Do like
you oughta, add acid to water").
12. Q: What is a chemical hygiene plan? ANSWER A written program
developed and implemented by an employer that sets forth procedures,
equipment, PPE, and work practices to protect employees from health hazards
of chemicals in the laboratory.
13. Q: What should be done with broken glassware? ANSWER Dispose of
it in a designated sharps or broken glass container, never in regular trash.
14. Q: What is the purpose of a spill kit? ANSWER To provide materials and
equipment necessary for containing and cleaning up chemical or biological
spills safely.
15. Q: How often should safety showers and eyewash stations be tested?
ANSWER Weekly for activation and flow verification, with documentation
maintained.
16. Q: What is the flash point of a chemical? ANSWER The lowest
temperature at which a liquid gives off enough vapor to form an ignitable
mixture with air.
17. Q: What does the term "right to know" refer to in laboratory safety?
ANSWER Employees' right to be informed about hazardous chemicals they
work with, including access to SDSs and training.
18. Q: What is the proper storage method for acids and bases? ANSWER
Store separately from each other in designated acid or base cabinets with
secondary containment.
19. Q: What is a Class A fire? ANSWER A fire involving ordinary
combustibles such as paper, wood, cloth, and rubber.
20. Q: What personal protective equipment is minimum for handling
wastewater samples? ANSWER Safety glasses, lab coat, and nitrile or latex
gloves.
21. Q: What is the purpose of secondary containment? ANSWER To
contain spills or leaks from primary containers, preventing environmental
contamination.
22. Q: How should mercury thermometers be handled if broken?
ANSWER Use a mercury spill kit following specific cleanup procedures;
evacuate area and ventilate; never use a vacuum cleaner.
, 23. Q: What is the proper procedure before leaving the laboratory?
ANSWER Remove PPE, wash hands thoroughly, ensure equipment is turned
off, and secure chemicals.
24. Q: What is the permissible exposure limit (PEL)? ANSWER The
maximum concentration of a chemical that a worker may be exposed to over a
time-weighted average.
25. Q: What should be included in a laboratory accident report? ANSWER
Date, time, location, individuals involved, description of incident, injuries
sustained, corrective actions, and witnesses.
26. Q: What is the proper method for pipetting hazardous materials?
ANSWER Use mechanical pipetting devices; never pipette by mouth.
27. Q: What is biological safety level (BSL) typical for wastewater
laboratories? ANSWER BSL-2, which involves moderate-risk biological
agents.
28. Q: How should compressed gas cylinders be stored? ANSWER Upright,
secured with chains or straps, with protective caps in place when not in use.
29. Q: What is the first action to take in case of a large chemical spill?
ANSWER Evacuate the area, alert others, and contact emergency response
personnel.
30. Q: What are flammable liquids storage requirements? ANSWER Store
in approved flammable storage cabinets, away from ignition sources, with
proper ventilation and grounding.
Section 2: Quality Assurance/Quality Control (Questions 31-60)
31. Q: What does QA/QC stand for? ANSWER Quality Assurance/Quality
Control.
32. Q: What is the purpose of a blank in analytical testing? ANSWER To
determine if contamination exists in reagents, glassware, or the analytical
procedure itself.
33. Q: What is a method blank? ANSWER A sample of reagent water or
matrix that is carried through the entire analytical procedure to check for
contamination.
34. Q: What is the difference between accuracy and precision? ANSWER
Accuracy measures how close a result is to the true value; precision measures
the reproducibility of repeated measurements.
UPDATED COLLECTION OF EXAM QUESTIONS AND VERIFIED ANSWERS
1. Q: What is the primary purpose of a safety shower in a wastewater
laboratory? ANSWER To provide immediate decontamination for personnel
exposed to hazardous chemicals or biological materials on their body or
clothing.
2. Q: How long should an eyewash station be activated when chemicals
splash into the eyes? ANSWER Minimum of 15 minutes of continuous
flushing while seeking medical attention.
3. Q: What does MSDS stand for (older term) and what has it been
replaced with? ANSWER Material Safety Data Sheet, replaced by SDS
(Safety Data Sheet) under GHS (Globally Harmonized System).
4. Q: What type of fire extinguisher should be used for electrical fires?
ANSWER Class C fire extinguisher (or ABC multipurpose extinguisher).
5. Q: What is the maximum allowable noise level for 8-hour exposure
according to OSHA? ANSWER 90 decibels (dBA) for 8-hour time-weighted
average.
6. Q: What color are oxidizer warning labels? ANSWER Yellow with black
text and symbol.
7. Q: What is the purpose of a fume hood in a laboratory? ANSWER To
protect laboratory personnel from inhaling toxic, offensive, or flammable
vapors by drawing contaminated air away from the work area.
8. Q: What is the minimum face velocity for a properly functioning fume
hood? ANSWER Typically 80-120 feet per minute (fpm), with 100 fpm being
ideal.
9. Q: What does PPE stand for? ANSWER Personal Protective Equipment.
10. Q: When should safety glasses be worn in the laboratory? ANSWER At
all times when in the laboratory, regardless of whether you are actively
performing procedures.
,11. Q: What is the proper procedure for diluting concentrated acids?
ANSWER Always add acid to water, never water to acid (remember: "Do like
you oughta, add acid to water").
12. Q: What is a chemical hygiene plan? ANSWER A written program
developed and implemented by an employer that sets forth procedures,
equipment, PPE, and work practices to protect employees from health hazards
of chemicals in the laboratory.
13. Q: What should be done with broken glassware? ANSWER Dispose of
it in a designated sharps or broken glass container, never in regular trash.
14. Q: What is the purpose of a spill kit? ANSWER To provide materials and
equipment necessary for containing and cleaning up chemical or biological
spills safely.
15. Q: How often should safety showers and eyewash stations be tested?
ANSWER Weekly for activation and flow verification, with documentation
maintained.
16. Q: What is the flash point of a chemical? ANSWER The lowest
temperature at which a liquid gives off enough vapor to form an ignitable
mixture with air.
17. Q: What does the term "right to know" refer to in laboratory safety?
ANSWER Employees' right to be informed about hazardous chemicals they
work with, including access to SDSs and training.
18. Q: What is the proper storage method for acids and bases? ANSWER
Store separately from each other in designated acid or base cabinets with
secondary containment.
19. Q: What is a Class A fire? ANSWER A fire involving ordinary
combustibles such as paper, wood, cloth, and rubber.
20. Q: What personal protective equipment is minimum for handling
wastewater samples? ANSWER Safety glasses, lab coat, and nitrile or latex
gloves.
21. Q: What is the purpose of secondary containment? ANSWER To
contain spills or leaks from primary containers, preventing environmental
contamination.
22. Q: How should mercury thermometers be handled if broken?
ANSWER Use a mercury spill kit following specific cleanup procedures;
evacuate area and ventilate; never use a vacuum cleaner.
, 23. Q: What is the proper procedure before leaving the laboratory?
ANSWER Remove PPE, wash hands thoroughly, ensure equipment is turned
off, and secure chemicals.
24. Q: What is the permissible exposure limit (PEL)? ANSWER The
maximum concentration of a chemical that a worker may be exposed to over a
time-weighted average.
25. Q: What should be included in a laboratory accident report? ANSWER
Date, time, location, individuals involved, description of incident, injuries
sustained, corrective actions, and witnesses.
26. Q: What is the proper method for pipetting hazardous materials?
ANSWER Use mechanical pipetting devices; never pipette by mouth.
27. Q: What is biological safety level (BSL) typical for wastewater
laboratories? ANSWER BSL-2, which involves moderate-risk biological
agents.
28. Q: How should compressed gas cylinders be stored? ANSWER Upright,
secured with chains or straps, with protective caps in place when not in use.
29. Q: What is the first action to take in case of a large chemical spill?
ANSWER Evacuate the area, alert others, and contact emergency response
personnel.
30. Q: What are flammable liquids storage requirements? ANSWER Store
in approved flammable storage cabinets, away from ignition sources, with
proper ventilation and grounding.
Section 2: Quality Assurance/Quality Control (Questions 31-60)
31. Q: What does QA/QC stand for? ANSWER Quality Assurance/Quality
Control.
32. Q: What is the purpose of a blank in analytical testing? ANSWER To
determine if contamination exists in reagents, glassware, or the analytical
procedure itself.
33. Q: What is a method blank? ANSWER A sample of reagent water or
matrix that is carried through the entire analytical procedure to check for
contamination.
34. Q: What is the difference between accuracy and precision? ANSWER
Accuracy measures how close a result is to the true value; precision measures
the reproducibility of repeated measurements.
