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Health Hazards of Abrasive Blasting

  • SILICA
  • NOISE
  • METALS
  • MECHANICAL
Silica

The second most common mineral in the earth’s crust is “Quartz” and “Crystalline Silica” (refer to the same thing). Is at the same time the major component of sand, rock, granite and mineral ore and it is present in toxic (Common-Sandblasters as Cristobalite, Tridymite, Tripoli and Quartz) and less/nontoxic forms (Diatomaceous earth, Diatomaceous silica, Diatomite, Silica Gel, Silicon Dioxide (amorphous)).

 

 

 

 

 

Abrasive Blasting

Process of using compressed air or steam to forcefully project abrasive particles onto a surface. Is frequently used for:

  • Cleaning sand from foundry castings
  • Cleaning and removing paint from metal surfaces
  • Finishing tombstones
  • Etching and frosting glass
Silicosis

Is a lung disease (disabling, non reversible and sometimes fatal) caused by the over exposure to breathable crystalline silica. There is no cure for silicosis.

Who Is At Risk?

  • Blasters using silica sand as an abrasive.
  • Blasters without adequate protection.
  • Workers near the blast areas:
    • Cleaners
    • Pot tenders
    • Painters
  • Silicosis is preventable if employers and employees work together to reduce exposures.

What are the Health Effects?

  • Early stages, may not notice any health effects.
  • As condition worsens, nodules become larger, making breathing more difficult.
  • Lungs can’t get enough oxygen from the air:
    • May die from suffocation.
  • May be complicated by tuberculosis.
  • Increase the risk of Lung Cancer.

No cure

  • Only treatment for secondary complications:
    • TB
    • Respiratory Failure
    • Lung Cancer
    • Heart Disease

 

NIHL
Sound Pathway

What is noise-induced hearing loss?

Every day, we experience sound in our environment, such as the sounds from television and radio, household appliances, and traffic. Normally, we hear these sounds at safe levels that do not affect our hearing. However, when we are exposed to harmful noise—sounds that are too loud or loud sounds that last a long time—sensitive structures in our inner ear can be damaged, causing noise-induced hearing loss (NIHL). These sensitive structures, called hair cells, are small sensory cells that convert sound energy into electrical signals that travel to the brain. Once damaged, our hair cells cannot grow back.

What are the effects of NIHL?

Hair Cells

Exposure to harmful sounds causes damage to the hair cells as well as the auditory, or hearing, nerve (see figure). Impulse sound can result in immediate hearing loss that may be permanent. This kind of hearing loss may be accompanied by tinnitus—a ringing, buzzing, or roaring in the ears or head—which may subside over time. Hearing loss and tinnitus may be experienced in one or both ears, and tinnitus may continue constantly or occasionally throughout a lifetime.

Continuous exposure to loud noise also can damage the structure of hair cells, resulting in hearing loss and tinnitus, although the process occurs more gradually than for impulse noise.

Exposure to impulse and continuous noise may cause only a temporary hearing loss. If a person regains hearing, the temporary hearing loss is called a temporary threshold shift. The temporary threshold shift largely disappears 16 to 48 hours after exposure to loud noise. You can prevent NIHL from both impulse and continuous noise by regularly using hearing protectors such as earplugs or earmuffs.

Noise Rules

Exposure Monitoring

The most important protection system is the continuous sound levels monitoring of the site and the equipments conditions. The exposure limits are defined by:

  • PEL = 90 dBA
  • AL = 85 dBA

Hose noise must be monitored:

  • If above PEL, engineering or administrative controls must be implemented
  • Seek out quieter equipment
Audiometric Testing

Audiometric testing is the evaluation of an individual’s ability to hear. It is a good practice testing each employee’s hearing upon hiring so that the initial results can be compared with future results to determine if any hearing loss has occurred due to workplace decibel levels. Baseline testing should be performed in the first year of employment, ideally within six months.

Testing should be done again the second year, and then every two years. If there is a high turnover of your employees, it is highly recommended to conduct testing annually. You shall conduct test:

  • If above AL (action level)
  • By qualified personnel
  • Annual - Standard Threshold Shift (STS)

It is also recommended to study the implementation of a hearing conservation program to ensure compliance with the legislative requirements designed to protect employees from noise-induced hearing loss. 

Hearing Protection
  • Is mandatory
  • Select the appropriate protection
  • Noise Reduction Rating (NRR):
    • Amount of decibels that a given device will reduce noise exposure:
      • L=TWA-NRR-7
  • Different types: Formable plugs, pre-molded plugs, ear muffs
Metals

There are 35 metals that concern us because of occupational or residential exposure; 23 of these are the heavy elements or "heavy metals": antimony, arsenic, bismuth, cadmium, cerium, chromium, cobalt, copper, gallium, gold, iron, lead, manganese, mercury, nickel, platinum, silver, tellurium, thallium, tin, uranium, vanadium, and zinc (Glance 1996). Interestingly, small amounts of these elements are common in our environment and diet and are actually necessary for good health, but large amounts of any of them may cause acute or chronic toxicity (poisoning). Heavy metal toxicity can result in damaged or reduced mental and central nervous function, lower energy levels, and damage to blood composition, lungs, kidneys, liver, and other vital organs. Long-term exposure may result in slowly progressing physical, muscular, and neurological degenerative processes that mimic Alzheimer's disease, Parkinson's disease, muscular dystrophy, and multiple sclerosis. Allergies are not uncommon and repeated long-term contact with some metals or their compounds may even cause cancer (International Occupational Safety and Health Information Centre 1999).

Arsenic

Arsenic is the most common cause of acute heavy metal poisoning in adults and is number 1 on the ATSDR's "Top 20 List." Arsenic is released into the environment by the smelting process of copper, zinc, and lead, as well as by the manufacturing of chemicals and glasses. Arsine gas is a common byproduct produced by the manufacturing of pesticides that contain arsenic. Arsenic may be also be found in water supplies worldwide, leading to exposure of shellfish, cod, and haddock. Other sources are paints, rat poisoning, fungicides, and wood preservatives. Target organs are the blood, kidneys, and central nervous, digestive, and skin systems (Roberts 1999; ATSDR ToxFAQs for Arsenic).

Lead

Lead is number 2 on the ATSDR's "Top 20 List." Lead accounts for most of the cases of pediatric heavy metal poisoning (Roberts 1999). It is a very soft metal and was used in pipes, drains, and soldering materials for many years. Millions of homes built before 1940 still contain lead (e.g., in painted surfaces), leading to chronic exposure from weathering, flaking, chalking, and dust. Every year, industry produces about 2.5 million tons of lead throughout the world. Most of this lead is used for batteries. The remainder is used for cable coverings, plumbing, ammunition, and fuel additives. Other uses are as paint pigments and in PVC plastics, x-ray shielding, crystal glass production, and pesticides. Target organs are the bones, brain, blood, kidneys, and thyroid gland (International Occupational Safety and Health Information Center 1999; ATSDR ToxFAQs for Lead).


Mercury

Number 3 on ATSDR's "Top 20 List" is mercury. Mercury is generated naturally in the environment from the degassing of the earth's crust, from volcanic emissions. It exists in three forms: elemental mercury and organic and inorganic mercury. Mining operations, chloralkali plants, and paper industries are significant producers of mercury (Goyer 1996). Atmospheric mercury is dispersed across the globe by winds and returns to the earth in rainfall, accumulating in aquatic food chains and fish in lakes (Clarkson 1990). Mercury compounds were added to paint as a fungicide until 1990. These compounds are now banned; however, old paint supplies and surfaces painted with these old supplies still exist. Mercury continues to be used in thermometers, thermostats, and dental amalgam. (Many researchers suspect dental amalgam as being a possible source of mercury toxicity [Omura et al. 1996; O'Brien 2001].) Medicines, such as mercurochrome and merthiolate, are still available. Algaecides and childhood vaccines are also potential sources. Inhalation is the most frequent cause of exposure to mercury. The organic form is readily absorbed in the gastrointestinal tract (90-100%); lesser but still significant amounts of inorganic mercury are absorbed in the gastrointestinal tract (7-15%). Target organs are the brain and kidneys (Roberts 1999; ATSDR ToxFAQs for Mercury).

 

Cadmium

Cadmium is a byproduct of the mining and smelting of lead and zinc and is number 7 on ATSDR's "Top 20 list." It is used in nickel-cadmium batteries, PVC plastics, and paint pigments. It can be found in soils because insecticides, fungicides, sludge, and commercial fertilizers that use cadmium are used in agriculture. Cadmium may be found in reservoirs containing shellfish. Cigarettes also contain cadmium. Lesser-known sources of exposure are dental alloys, electroplating, motor oil, and exhaust. Inhalation accounts for 15-50% of absorption through the respiratory system; 2-7% of ingested cadmium is absorbed in the gastrointestinal system. Target organs are the liver, placenta, kidneys, lungs, brain, and bones (Roberts 1999; ATSDR ToxFAQs for Cadmium).


Iron

Discussion of iron toxicity in this protocol is limited to ingested or environmental exposure. Iron overload disease (hemochromatosis), an inherited disorder, is discussed in a separate protocol. Iron does not appear on the ATSDR's "Top 20 List," but it is a heavy metal of concern, particularly because ingesting dietary iron supplements may acutely poison young children (e.g., as few as five to nine 30-mg iron tablets for a 30-lb child).

Ingestion accounts for most of the toxic effects of iron because iron is absorbed rapidly in the gastrointestinal tract. The corrosive nature of iron seems to further increase the absorption. Most overdoses appear to be the result of children mistaking red-coated ferrous sulfate tablets or adult multivitamin preparations for candy. (Fatalities from overdoses have decreased significantly with the introduction of child-proof packaging. In recent years, blister packaging and the requirement that containers with 250 mg or more of iron have child-proof bottle caps have helped reduce accidental ingestion and overdose of iron tablets by children.) Other sources of iron are drinking water, iron pipes, and cookware. Target organs are the liver, cardiovascular system, and kidneys (Roberts 1999).

Aluminum

Although aluminum is not a heavy metal (specific gravity of 2.55-2.80), it makes up about 8% of the surface of the earth and is the third most abundant element (ATSDR ToxFAQs for Aluminum). It is readily available for human ingestion through the use of food additives, antacids, buffered aspirin, astringents, nasal sprays, and antiperspirants; from drinking water; from automobile exhaust and tobacco smoke; and from using aluminum foil, aluminum cookware, cans, ceramics, and fireworks (ATSDR ToxFAQs for Aluminum).

Studies began to emerge about 20 years ago suggesting that aluminum might have a possible connection with developing Alzheimer's disease when researchers found what they considered to be significant amounts of aluminum in the brain tissue of Alzheimer's patients. Although aluminum was also found in the brain tissue of people who did not have Alzheimer's disease, recommendations to avoid sources of aluminum received widespread public attention. As a result, many organizations and individuals reached a level of concern that prompted them to dispose of all their aluminum cookware and storage containers and to become wary of other possible sources of aluminum, such as soda cans, personal care products, and even their drinking water (Anon. 1993).

However, the World Health Organization (WHO 1998) concluded that, although there were studies that demonstrate a positive relationship between aluminum in drinking water and Alzheimer's disease, the WHO had reservations about a causal relationship because the studies did not account for total aluminum intake from all possible sources. Although there is no conclusive evidence for or against aluminum as a primary cause for Alzheimer's disease, most researchers agree that it is an important factor in the dementia component and most certainly deserves continuing research efforts. Therefore, at this time, reducing exposure to aluminum is a personal decision. Workers in the automobile manufacturing industry also have concerns about long-term exposure to aluminum (contained in metal working fluids) in the workplace and the development of degenerative muscular conditions and cancer (Brown 1998; Bardin et al. 2000). The ATSDR has compiled a ToxFAQs for Aluminum to answer the most frequently asked health questions about aluminum. Target organs for aluminum are the central nervous system, kidney, and digestive system.

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 can 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 can be found on the Shipyard Employment e-Tool.

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 can be found on OSHA's Ergonomics Safety and Health 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 Confined Spaces Safety and Health Topics Page, or in the Shipyard e-tools.

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 e-Tool, 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 e-Tool 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 Heat Stress Safety and Health Topics Page.

Environment

Look through this information to know about the environmental impact of our products.

Save Money protecting the environment

Do you know how much money could you save with the adequate media abrasive and waste management, look through profitability, lead based paints considerations.

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