A high number of toxic products and cargoes are found in shipyard
employment. Additionally, many shipyard operations use toxic materials
or produce toxic atmospheres. Because of the confined and enclosed nature of
the spaces where these products are generally located, the hazard is
In addition to materials that are inherently toxic,
certain maritime cargoes and shipyard operations produce toxic gases as a
One such by-product is hydrogen sulfide (H2S),
a naturally occurring poisonous gas is hard to detect and
cause shipyard fatalities.
Hydrogen sulfide is found in tanks that have carried sour crude oil,
bunker oil, or drilling mud, as well as in fish holds and sewage tanks. The
OSHA Maritime PEL for H2S is 10
ppm. The American Conference of Governmental Industrial Hygienists (ACGIH)
sets the threshold limit value (TLV) at 10 ppm, with a 15 ppm short-term
exposure limit (STEL).
Carbon monoxide (CO) is another common toxic gas
found in shipyards. It is produced by combustion processes such as welding,
spontaneous combustion, and internal combustion engines. Carbon monoxide
is odorless and colorless, making it especially dangerous. It has a PEL of
50 ppm and an ACGIH TLV of 25 ppm.
|Requirements and Example Solutions
- Spaces that have contained toxic, corrosive,
irritating, or fumigated atmospheres or residues must be tested for these
materials before entry. Examples of these spaces include: [29 CFR 1915.12(c)]
- Cargo tanks
- Ship holds
- Fuel tanks
- Sewage tanks
- Adjacent spaces
- Piping and pumps that carry toxic material
- In order for the space to be labeled "Safe for
Workers," the toxic atmosphere must be less than the OSHA PEL,
and not be immediately dangerous to life or health (IDLH). [29 CFR 1915.12(c)]
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- In the absence of a specific OSHA PEL, employers should consult with
other available sources that provide guidance with respect to the
concentration and duration of employee exposure to a toxic substance.
These sources include the ACGIH TLVs, NIOSH Recommended Exposure
Limits (RELs), and the American Industrial Hygiene Association
Workplace Employee Exposure Limits (WEELs).