NIOSH Recommends Engineering Controls at Shipbuilding and Repair Company

Uncontrolled welding fumes created during certain operations at a shipbuilding and ship repair company could have contributed to some employees being overexposed to manganese, according to a new NIOSH health hazard evaluation (HHE) report. The report recently became available on the agency’s website but summarizes the findings of a NIOSH investigation of the company’s facilities that spanned 2023–2024. An employer representative requested the HHE, describing concerns about potential exposures to airborne metals and noise at the company’s two locations: one where new vessels are built and one where ships are repaired.

NIOSH’s evaluation of employees’ exposures to airborne metals and noise took place over four days in April 2024. Agency staff collected 41 full-shift personal air samples and 52 full-shift personal noise exposure measurements between the company’s two facilities. While no workers were exposed to metals above OSHA’s occupational exposure limits, structural welders at both the new build and repair locations as well as pipe welders, fitters, and helper-tackers at the repair facility were exposed to manganese above both NIOSH’s recommended exposure limit (REL) of 1 mg/m3 and ACGIH’s threshold limit value of 0.07 mg/m3, adjusted for a 10-hour shift. NIOSH’s report identifies inoperable building exhaust fans and instances of welders working very close to one another as potential factors that contributed to increased exposures to welding fumes.

Structural welders and fitters at the new build location and workers performing abrasive blasting at the repair location were exposed to noise above NIOSH’s REL and both OSHA’s action level and permissible exposure limit for noise, the NIOSH evaluation found. The HHE identified additional job titles exposed to noise levels below the OSHA PEL but above the NIOSH REL and OSHA action level. In the repair facility, these job titles included welder-structural, fitter, helper-grinding, and skid loader operator. The job titles welder-pipe, helper-tacker, pipefitter, and forklift operator had similar levels of noise exposure at the company’s new build facility. NIOSH evaluators found that measured sound levels during different tasks and tool use “could vary substantially.” For example, sound levels measured during welding were 80.4–111.3 dBA, while sound levels measured at the plasma cutter were 77.5–102.4 dBA, the report notes. Agency staff also identified noise from compressed air within the workplace, with sound levels from one leaking compressed air hose measuring 98 dBA.

NIOSH recommended using engineering controls like portable welding fume extractors and general building ventilation as well as sound barriers at noisy equipment to help prevent or reduce workers’ exposures to manganese and noise. The agency also urged the company to provide appropriate respiratory protection for those overexposed to manganese until exposures can be reduced below relevant OELs. The employer should similarly ensure that workers wear appropriate hearing protection, NIOSH notes. Other ways the company could reduce noise within its facilities include properly adjusting and maintaining equipment and implementing a “Buy Quiet” program, which involves replacing or purchasing equipment that generates less noise.

For more information, read the HHE report (PDF) on the NIOSH website.