CMC Maritime Safety Regulations & Compliance 2 — Questions and Answers
Question 1: Under 29 CFR 1910.146, which condition classifies a vessel tank as a 'permit-required confined space'?
- It has only one access point
- It contains a hazardous atmosphere or engulfment hazard (Correct answer)
- It requires a ladder for entry
- It has a volume greater than 50 cubic feet
Correct answer: It contains a hazardous atmosphere or engulfment hazard
A permit-required confined space under OSHA 29 CFR 1910.146 is one that contains or has potential to contain a serious hazard such as a hazardous atmosphere or engulfment material.
Question 2: Which USCG regulation requires a Marine Chemist certificate before hot work can be performed on fuel tanks aboard vessels?
- 46 CFR Part 35 (Correct answer)
- 33 CFR Part 126
- 46 CFR Part 147
- 33 CFR Part 155
Correct answer: 46 CFR Part 35
46 CFR Part 35 governs inspection of tankships and requires a Marine Chemist certificate for hot work on fuel tanks and adjacent spaces.
Question 3: When a Marine Chemist issues a 'Safe for Hot Work' certificate, what must the attending worker do if conditions change significantly?
- Continue work until the certificate expires
- Immediately stop work and recontact the Marine Chemist (Correct answer)
- Increase ventilation and proceed cautiously
- Contact the vessel master only
Correct answer: Immediately stop work and recontact the Marine Chemist
If conditions change materially after a certificate is issued, work must cease and the Marine Chemist must be recalled to reassess the space.
Question 4: NFPA 306 defines the maximum allowable oxygen concentration for a 'Safe for Workers' atmosphere in a confined space as:
- 19.5% to 23.5% (Correct answer)
- 18.0% to 22.0%
- 20.0% to 25.0%
- 17.0% to 21.0%
Correct answer: 19.5% to 23.5%
NFPA 306 specifies that oxygen concentrations must be between 19.5% and 23.5% for a space to be certified Safe for Workers.
Question 5: Which document serves as the primary NFPA standard specifically governing control of gas hazards on vessels?
- NFPA 30
- NFPA 306 (Correct answer)
- NFPA 72
- NFPA 654
Correct answer: NFPA 306
NFPA 306, 'Standard for the Control of Gas Hazards on Vessels,' is the primary document Marine Chemists use for vessel gas hazard assessments.
Question 6: Under MARPOL Annex II, which category of noxious liquid substances requires tank washing before departure from an unloading port?
- Category Z only
- Categories X and Y (Correct answer)
- Category Y only
- Categories X, Y, and Z
Correct answer: Categories X and Y
MARPOL Annex II Categories X and Y require prewash and tank cleaning before a vessel may depart the unloading port.
Question 7: A Marine Chemist discovers that CO levels in a void space are 150 ppm. Under NFPA 306, what certificate should be issued?
- Safe for Workers
- Safe for Hot Work
- Not Safe (Correct answer)
- Safe for Entry with SCBA only
Correct answer: Not Safe
CO levels of 150 ppm exceed the 35 ppm TWA limit and the 200 ppm ceiling, making the space 'Not Safe' for either workers or hot work.
CMC Maritime Safety Regulations & Compliance 2
Under 29 CFR 1910.146, which condition classifies a vessel tank as a 'permit-required confined space'?