Executive Summary

OSHA developed this document to alert shipyard employers and their employees about abrasive blasting hazards and the controls that can be implemented to reduce, avoid or eliminate them. This document focuses on air contaminants because they are a major hazard during abrasive blasting. Other abrasive blasting safety and health hazards are discussed along with information regarding applicable regulations and control methods.

This guidance document provides employers with recommendations and information on how to protect their employees from the various hazards of abrasive blasting operations. These recommendations range from engineering controls, exposure monitoring and medical surveillance, to training on the OSHA Hazard Communication and PPE standards. In addition, OSHA recommends that employers perform an inspection of the worksite to identify additional hazards that may be present, such as excessive noise, static electricity, confined spaces, and heat and fall hazards. Where possible, OSHA has included the website address where employers may find additional information on specific topics. OSHA recommends that employers spend time evaluating each of the discussed hazards, the suggested preventative measures and the abatement steps that have been detailed.

Although this guidance document is designed specifically for shipyard employment, OSHA hopes that employers with similar work environments may also find this information useful.

Employers with limited expertise in this area can obtain services from (1) their state on-site safety and health consultation program; (2) industry associations, such as Shipbuilders Council of America, National Shipbuilders Research Program or National Institute for Occupational Safety and Health; (3) risk management services through their workers' compensation insurance provider; or (4) an industrial hygienist or other qualified health and safety consultant. A directory of free state safety and health consultation services is available electronically at OSHA's website or by contacting your local OSHA office. A listing of occupational and environmental health and safety consultants by state is available through the American Industrial Hygiene Association (AIHA) and may be accessed electronically or by calling AIHA Customer Service in Fairfax, Virginia at (703) 849-8888. Workplace health and safety consultants may also be located in the yellow pages of your telephone directory for safety and/or environmental engineers.

Background

In the shipbuilding and ship repair industry, abrasive blasting is the most common surface preparation technique used to remove old paint and other surface materials such as rust, mill scale, dirt, and salts. Abrasive blasting might be conducted during vessel fabrication (e.g., on piping, steel plates and steel members used in structural assemblies, and other miscellaneous materials) and during maintenance and repair operations that include blasting and painting the ship's hull, and interior tanks and spaces. Surface preparation techniques, such as abrasive blasting, are also one of the most significant sources of shipyard wastes and pollution. ⁽¹⁾

In abrasive blasting, compressed air is used to propel abrasive material from a blast pot, through a blasting hose to a nozzle, where it is directed to the work area at high velocity by the operator. Air pressure is typically high, at 100 pounds per square inch, and nozzle velocities can approach 650 - 1,700 feet per second. ⁽²⁾ Abrasive blasting is usually conducted manually within a blast building, a dry dock, a floating dry dock, graving dock, shipways, vessel sections, on the ground, on board a vessel, and at the pier. ⁽³⁾ Automated abrasive blasting machines such as centrifugal blasting machines are also used in shipyards to prepare materials prior to priming or painting.

Hazards

Shipyard employees who engage in abrasive blasting are at an increased risk of exposure to toxic dusts, high noise levels, and a range of other safety and health hazards. Helpers (e.g., the "pot tender" and cleanup personnel) and others may also be at risk if they work in the vicinity of areas where abrasive blasting is conducted.

Air Contaminants

Potential exposure to dust and air contaminants is the primary health hazard associated with abrasive blasting. Abrasive blasting can generate large quantities of dust that can contain high levels of toxic air contaminants. The source of the air contaminants includes the base material being blasted, the surface coating(s) being removed, the abrasive being used, and any abrasive contamination from previous blasting operations. ⁽⁴⁾ This means that employees can have exposures to multiple air contaminants from both the abrasive and the surface being blasted. Potential air contaminants that might be associated with abrasive blasting in shipyards and their sources are listed in Table 1.

Table 1. Potential Air Contaminants Associated with Abrasive Blasting in Shipyards

Base Materials

The base materials used to fabricate ships include iron-containing (e.g., carbon steel) and non-iron-containing metals. Various grades of mild and high strength steel are used for the structural framework of most ships while aluminum and other non-iron-containing materials are used for some superstructures and other areas with specific corrosion resistance and structural requirements. Other materials such as galvanized steel, stainless steel, and copper alloys are used to a much lesser extent. Depending on the base material being blasted, potential air contaminants might include aluminum, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc.

Surface Coatings

The interior and exterior surfaces of ships are protected with coatings that include zinc-based pre-construction primers (shop primers) and metal-based anticorrosive and antifouling paints. Antifouling paints are used on the hulls of ships to prevent the buildup of marine organisms (e.g., algae, bacteria, and barnacles) and typically include copper-based and tributyl tin-based paints. Metal-based paints are used to protect ship surfaces from corrosion and can contain up to 30 percent heavy metals. Lead compounds, such as lead chromate and red lead tetraoxide, have been used extensively in marine paint. Depending on the surface coating being blasted, potential air contaminants might include barium, cadmium, chromium, copper, lead, zinc, organotin compounds, and other types of air contaminants.

Abrasive Blasting Media

Common blasting abrasives used for paint removal and surface preparation in shipyard employment include coal slag, copper slag, and other metallic grit and shot. Traditionally, silica sand was used as a blasting abrasive; however, the majority of shipyards no longer use silica sand because of the health hazards associated with silica dust. Silica dust is generated by using blasting abrasives that contain crystalline silica (e.g., quartz rock, river sand, and beach sand) and when blasting crystalline silica-containing surfaces such as concrete or masonry. Employees who breathe in fine (respirable) particles of crystalline silica are at risk of developing silicosis, a stiffening and scarring of the lungs which can result in death.

The use of non-silica abrasives, such as coal and smelter slags, and metallic (e.g., steel shot, cast iron grit, cast iron shot) and mineral abrasives (e.g., garnet, olivine, and staurolite), results in nondetectable or lower levels of airborne crystalline silica; but levels of other hazardous air contaminants can be elevated, depending on the abrasive. For example, in a NIOSH-sponsored field study that evaluated silica sand alternatives for abrasive blasting, coal slag generated substantially lower airborne levels of crystalline silica than silica sand ⁽⁵⁾. But, airborne levels of other air contaminants (arsenic, beryllium, cadmium, chromium, lead, manganese, nickel, titanium and vanadium) were two to four times higher than for silica sand. Other researchers have reported that abrasive blasting with copper slag can generate arsenic, chromium, and lead levels that exceed the OSHA Permissible Exposure Limits (PELs) for these substances.

The levels of heavy metals in non-silica abrasives are highly variable depending on the type of raw material sources and/or the manufacturing processes used to make the abrasives. ⁽⁵⁾ Abrasive blasting media from coal slag will typically contain nickel and vanadium and a variety of other metals depending on the source of the coal used to make the slag. Copper slag from primary smelters contains significant levels of barium, cobalt, copper, chromium (trivalent), and nickel; whereas copper slag from secondary smelters might contain significant levels of arsenic and lead. Nickel slag typically contains elevated levels of copper, chromium (trivalent), and nickel and lower levels of cobalt and vanadium. ⁽⁶⁾

Health Hazards

A summary of the potential health hazards associated with abrasive blasting air contaminants and their corresponding OSHA PELs are listed in Table 2.

Table 2. Hazards of Air Contaminants Associated with Abrasive Blasting in Shipyards

Control Measures

Exposure to hazardous air contaminants during abrasive blasting can be controlled through the combined use of the following control measures: engineering controls; work practices; personal hygiene; waste management and prevention programs; and personal protective equipment (PPE);

Exposure Monitoring

OSHA recommends that air sampling be conducted by trained personnel in all abrasive blasting applications. This sampling is necessary to: (1) measure employee exposure to airborne contaminants (e.g., total dust, respirable crystalline silica and heavy metals); (2) select the proper PPE; and (3) evaluate the effectiveness of engineering controls. Exposure monitoring must be performed when abrasive blasting applications may expose employees to arsenic (29 CFR 1915.1018), cadmium (29 CFR 1915.1027), hexavalent chromium (29 CFR 1915.1026) or lead (29 CFR 1915.1025). If concentrations of airborne contaminants are high, corrective measures should be taken to reduce exposures and sampling should be repeated to confirm reduced exposures. Air samples should to be collected and analyzed according to OSHA methods or their equivalent.

Medical Surveillance

Specific substances requiring medical surveillance that might be encountered in shipyards during abrasive blasting include arsenic (29 CFR 1915.1018), cadmium (29 CFR 1915.1027), hexavalent chromium (29 CFR 1915.1026) and lead (29 CFR 1915.1025). Depending on the levels of these air contaminants, employers may need to comply with the requirements of one or more substance-specific standards, including the provision of medical surveillance. Medical surveillance requirements vary depending on the substance and may include: work and medical histories, smoking histories, chest X-rays, blood and urine testing, medical examinations, and other tests or procedures.

Some air contaminants, such as crystalline silica, do not have OSHA medical surveillance requirements. However, NIOSH recommends that medical examinations be available to all employees who may be exposed to crystalline silica. Examination should at least include: (1) a medical and occupational history to collect data on employee exposure to crystalline silica and signs and symptoms of respiratory disease; (2) a chest X-ray; (3) pulmonary function testing; and (4) an annual evaluation for tuberculosis. (8)

OSHA recommends that all employers engaged in abrasive blasting evaluate the risks abrasive blasting dusts present to exposed employees and determine what medical surveillance, if any, is required. The need for medical surveillance can usually be determined by conducting air sampling to measure and evaluate the levels of regulated air contaminants.

Training and Information

OSHA recommends that employers provide information and training to employees who engage in abrasive blasting activities. This information should incorporate the training requirements of the OSHA Hazard Communication (29 CFR 1915.1200) and Personal Protective Equipment (29 CFR 1915.152) standards. If necessary, the training requirements of applicable substance-specific standards (arsenic, cadmium, hexavalent chromium, and lead) must also be addressed. Typical information and training includes:

• The location and availability of the written hazard communication program and material safety data sheets (MSDSs) for abrasives;
• Instruction about the purpose and set-up of regulated areas marking the boundaries of blasting areas containing hazardous materials, sand, and dusts;
• Methods and observations that may be used to detect the presence or release of hazardous air contaminants, such as workplace air sampling outside of the blasting area;
• Results of any air sampling the employer or others have conducted for levels of hazardous air contaminants in the workplace;
• The physical and health hazards of the air contaminants employees are exposed to. Employees should be made aware of the importance of recognizing relevant symptoms and encouraged to report such symptoms to their employer for further evaluation and advice;
• Discussion about the importance of engineering controls, work practices, and personal hygiene in reducing exposure to hazardous air contaminants;
• Instruction about the need, use, limitations, and care of appropriate PPE (including protective clothing, and respiratory, hearing, and fall protection);
• Other controls the employer has implemented to protect employees from exposure to hazardous air contaminants, such as medical surveillance programs;
• Information regarding applicable OSHA standards, other relevant safety and health hazards and the control measures implemented to protect employees; and
• A copy of this guidance document.

Employers engaging in abrasive blasting should research the relevant training requirements to ensure that their employees are protected. The above listing may not be all-inclusive.

Other Safety and Health Hazards

Although this guidance document focuses on the hazards of air contaminants associated with abrasive blasting, employers must be aware of other safety and health hazards that are present in the workplace. OSHA recommends that employers perform an inspection of the worksite, prior to work taking place, to determine what hazards exist and what precautions need to be taken. Some of these hazards are discussed below.

Exposure to Noise

Abrasive blasting produces noise levels that can cause permanent hearing loss in unprotected employees and others close to the blasting process. The main source of noise is the discharge of compressed air at the blast nozzle. Other noise sources during manual blasting include: (1) the supply air inside the operator's helmet; (2) the impact of the abrasive on the surface being blasted; (3) air compressors; (4) exhaust ventilation systems; and (5) air releases during grit pot blow-down. Small abrasive blasting cabinets are also significant sources of noise exposure for operators.

OSHA regulates occupational noise exposure in shipyards under 29 CFR 1910.95. The current PEL is 90 dB(A) with employers taking action at 85 dB(A), both measured as eight-hour time-weighted averages. For those employees exposed to elevated levels of noise, employers must implement the requirements of the noise standard which include provisions for engineering and administrative controls, employee noise monitoring, audiometric testing, hearing protectors, training, and recordkeeping.

Additional information may be found on OSHA's Occupational Noise Exposure Safety and Health Topics Page, including information on recognition, evaluation, control, compliance, and training.

High-Speed Particles

Employees engaged in abrasive blasting can be struck by high-speed particles from the blasting media or the surface being blasted (substrate). Potential injuries can include particles becoming embedded in the skin, eye damage, severe cuts, and burns. Control measures to prevent these injuries include: (1) never pointing a blast nozzle at a person; (2) using a dead-man control device at the nozzle end of the blasting hose; (3) ensuring, where possible, that only one employee operates each blast nozzle; (4) installing guards to protect the operator from high-speed particles; (5) conducting abrasive blasting in a blasting enclosure or an area isolated from the workplace to reduce the possibility of employees and others being struck by high-speed particles; and (6) using appropriate personal protective equipment (PPE) when blowing off with 30 psi (pounds per square inch) air.

High-pressure Hazards

Abrasive blasting operators and other employees in the blasting area can be exposed to high-pressure hazards through contact with high-pressure air or water streams, uncontrolled high-pressure hoses, and air or water leaks in the equipment. Injuries can be very serious and include loss of sight and body parts (e.g., fingers and hands). Preventive measures include the following:

• Controlled access to the blasting area;
• Use of a dead-man control on the blast nozzle;
• Use of metal nozzle and hose couplings;
• Use of hose-coupling safety locks and hose whip checks;
• Inspection of all hoses and connections prior to use; and
• Use of appropriate PPE.

Additional information may be found on the Shipyard eTool, under cleaning operations.

Static Electricity

Static electricity can be generated by abrasive blasting equipment, the surfaces being blasted, and exhaust ventilation systems (fans and ductwork). Static electricity can shock employees and cause fires and explosions by igniting flammable/combustible atmospheres or materials. The buildup of static electricity can be prevented through the proper use of bonding and grounding. Additionally, blast hoses can be constructed with anti-static rubber linings or fitted with a ground wire or similar mechanism to dissipate static electrical charges. Additional information may be found on the Shipyard Employment eTool.

Vibration and Other Ergonomic Hazards

Abrasive blasting operators are exposed to hand-arm vibration from the force of the abrasive moving through the blast hose. Prolonged use of abrasive blasting equipment can damage the nerves and blood vessels in the fingers and result in a condition known as vibration syndrome (also known as vibration white finger and Raynaud's disease). The signs and symptoms of vibration syndrome include numbness, tingling, blanching (fingers turning pale and ashen), pain, and flushing. In advanced cases, individuals lose their manipulative skills (dexterity) and the ability to distinguish between hot and cold objects. If exposure to vibration continues, skin necrosis and gangrene can occur.

Preventive measures for vibration syndrome include: (1) the use of vibration-reduced equipment such as vibration-isolating handles incorporated into blasting nozzles; (2) reducing the extent and duration of continuous exposure to vibration through job rotation or more frequent breaks (e.g., a 10-minute break after each hour of continuous blasting); (3) frequent and careful maintenance of blasting equipment according to manufacturers' recommendations; and (4) the use of protective gloves to keep hands warm and dry while on the job. Certain glove designs also reduce vibration.

Additional information on vibration and ergonomic hazards may be found on OSHA's Ergonomics Safety and Health Topics Page.

Confined Spaces

Confined and enclosed spaces in vessels or vessel sections (such as cargo tanks or holds, pump or engine rooms, storage lockers, and tanks containing or having last contained hazardous substances) can contain dangerous atmospheres resulting from oxygen deficiency or enrichment and flammable, combustible, toxic, corrosive or irritating substances. Abrasive blasting is a spark-producing operation that is considered "hot" work unless it is physically isolated from a flammable or combustible atmosphere. Abrasive blasting in confined and enclosed spaces can also introduce additional air contaminants such as heavy metals from the abrasive media and/or the surfaces blasted. Shipyard employers engaged in abrasive blasting in confined and enclosed spaces must meet OSHA requirements for confined space work (29 CFR 1915 Subpart B), surface preparation and preservation (29 CFR 1915 Subpart C) (not limited to confined/enclosed spaces), and ventilation. (29 CFR 1910.94).

In addition, other hazards inherent in the work performed in confined and enclosed spaces may include limited access, ladders, scaffolds, electrical circuits, unguarded openings and others. Such hazards must be addressed and specific safety practices followed to ensure that spaces are entered and worked in safely. Additional information on confined spaces can be found on the OSHA's Confined Spaces Safety and Health Topics Page, or in the Shipyard Employment eTool.

Working at Heights

Falls are a leading cause of fatalities in shipyards. Fall hazards for abrasive blasters include: (1) surges from drops in pressure in the hose line that can be sufficient enough to throw the blaster from the work surface; (2) shocks from static electricity that might cause the blaster to lose balance and fall when working at heights; and (3) blasting hoods that visually restrict the vision of the blaster.

Preventive measures include: (1) protecting the blaster with proper fall protection when adequate protection against falling cannot be provided by guard railings; (2) bonding and grounding blasting equipment and wearing appropriate gloves and boots to insulate from static electricity; and (3) working from scaffolds, not from ladders. Other preventive measures include covering or guarding holes and deck openings, providing adequate lighting so that blasters can see the physical limits of the work surface, and all control devices, and frequently removing abrasive media from all horizontal surfaces on staging or other elevated work surfaces.

Additional information on fall protection can be found in OSHA's Shipyard Employment eTool, under Working Surfaces.

Slips and Trips

Abrasive blasting operators are exposed to tripping hazards and slippery work surfaces. High levels of airborne dust can also obstruct the blaster's vision. Preventive measures for slips and trips can be found in OSHA's Shipyard Employment eTool, under Housekeeping and Illumination.

Heat

Abrasive blasting operators are at risk of heat-related illnesses due to the PPE that is worn (blast helmets and protective suits, sometimes for long periods of time), the work activity or physical demands of the job, and environmental conditions (i.e., temperature, humidity, and air movement). Additional information on reducing the risk of heat-related illnesses can be found on the OSHA Occupational Heat Exposure Safety and Health Topics Page.

Applicable Standards

References

Additional Sources of Information

ACGIH, 2001b. Industrial Ventilation - A Manual of Recommended Practice. 24th Edition. American Conference of Governmental Industrial Hygienists. Cincinnati: ACGIH.

Environment Canada, 1995. Best Management Practices (BMPs) for Ship and Boat Building and Repair Industry in British Columbia. Fraser Pollution Abatement Program, Environment Canada, North Vancouver, British Columbia. DOE FRAP 1995-14. August 30.

EPA, 1991. Guides to Pollution Prevention: The Marine Maintenance and Repair Industry. U.S. Environmental Protection Agency, Office of Research and Development, Risk Reduction Engineering Laboratory and Center for Environmental Research Information. EPA/625/7-91/015. October.

EPA, 2000. A Guide for Ship Scrappers - Tips for Regulatory Compliance. U.S. Environmental Protection Agency, Office of Enforcement and Compliance Assurance, Federal Facilities Enforcement Office. EPA 315-B-00-001. Summer 2000.

Kura, B., S. Lacoste, and P.V. Patibanda. [No date] Multimedia Pollutant Emissions from the Shipbuilding Facilities. This paper presents information obtained from a University of New Orleans research project entitled "Integrated Environmental Management Plan for Shipbuilding Facilities."

NIOSH, 1986. Occupational Respiratory Diseases. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication No. 86-102. September.

NIOSH, 1992b. NIOSH Alert - Preventing Lead Poisoning in Construction Workers. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication No. 91-116a. April.

NIOSH, 1996. Request for Assistance in Preventing Silicosis and Deaths in Construction Workers. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication No. 96-112.

NIOSH, 2002. Final Survey Report: Ergonomics Interventions for Ship Repair Processes at Todd Pacific Shipyards Corporation, Seattle, Washington. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology. Report No. EPHB 229-18c. December.

NIOSH, 2003. NIOSH Pocket Guide to Chemical Hazards. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication No. 97-140. January.

OSHA Consultation Services.

PPRC, 1997a. Pollution Prevention at Shipyards - A Northwest Industry Roundtable Report. Pacific Northwest Pollution Prevention Resource Center, Seattle, Washington. May 13.

PPRC, 1997b. Small Shipyards and Boatyards in Oregon: Environmental Issues & P2 Opportunities. A Northwest Industry Roundtable Report. Pacific Northwest Pollution Prevention Resource Center (PPRC) Roundtable Discussion, Coos Bay, Oregon. November 10.

OSHA Shipyard Employment eTool. Mechanical Removers (under Ship Repair - Surface Prep). U.S. Department of Labor. Occupational Safety and Health Administration.

OSHA Silica eTool: Taking Action to Protect Against Silica. U.S. Department of Labor. Occupational Safety and Health Administration.

Stephenson, D., T. Spear, M. Seymour, and L. Cashell, 2002. Airborne Exposure to Heavy Metals and Total Particulate During Abrasive Blasting Using Copper Slag Abrasive. Applied Occupational and Environmental Hygiene 17(6): 437-443.