Thermal spraying and health risks

Remarkably little has been written about the health risks of thermal spraying, especially when compared to the health risks of welding. However, a French article by Hériaud-Kraemer et al. Appeared in 2003 in which the health risks associated with thermal spraying were listed.

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Health risks

Employees who work in such processes may encounter the following risks at work.

ExposureSpecific riskFabricsPossible effect
Exposure to gases and vaporsCombustion products of gas from flame sprayingCO2 carbon dioxide, CO carbon monoxideChoking
 Reaction products of the process with the ambient air and residues of the propellant gasDO NOTx nitrous fumes, O3 Ozone, Ar Argon, H.2 hydrogen, He helium, and N2 nitrogenIrritation to the respiratory tract, choking
 Vapors from the material being sprayed moltenMetals such as chrome, nickel, zincMetal fume fever
Exposure to dust and fine particlesDust particles that are released during the process have different sizes and can therefore end up in different places in the lung.Nickel, Cobalt, Copper, Aluminum, Chrome and Chrome 6Chronic lung damage, partly carcinogenic
Exposure to noiseWhen spraying, high noise levels are reached well above 85 dB (A) Noise hearing
Exposure to non-ionizing radiationA wide range of radiation is generated when spraying, ranging from infrared to ultraviolet eye injury from UV or infrared radiation, skin irritation
Exposure to heatThe tip of the spray gun and the plume are very hot, especially when spraying plasma Burns
Electrical risksEspecially with electrical spraying Electrical injury, electrocution
Explosion dangerUnstable powders, reaction with the surrounding atmosphere, presence of an ignition point 
Self-ignition of powderParticularly a risk with metals, depending on the size and shape of the particles 
AccidentsRisk from handling heavy loads and handling robots 

Metal particles

The molten materials used can present various risks, including those of the following metals:

MetalHealth effect
ChromeCarcinogenic, especially for lung
CobaltLung damage 'cobalt lung'
CopperMetal fume fever1
Ironsiderose2
ManganeseLung damage, neurotoxic
NikkelCarcinogenic, especially for lung
ZincMetal fume fever

1 Metal fume fever is an acute illness (toxic inhalation fever) that resembles the flu. Symptoms usually begin a few hours after exposure with a general feeling of malaise, thirst, dry cough, sweat on the forehead, muscle pain, pain in the extremities and fever. The complaints can be accompanied by chest pain and tightness or a tight feeling. The complaints also disappear spontaneously within 24-48 hours.
2 Lung disease caused by inhaling iron or iron oxide dust particles.

Diseases

Potential health consequences of thermal spraying in general are mainly due to inhalation of gas, vapors or dust. This can lead to acute respiratory problems such as pulmonary edema, chemical pneumonia, RADS, metal fume fever or to chronic respiratory problems such as chronic bronchitis or bronchiolitis. But there is not much literature on health complaints among employees who use thermal spraying.

In 2003, an employee in the United States died after two days of thermal spraying with nickel and chromium. There was no proper ventilation and respiratory protection was insufficient. This worker developed progressive symptoms of coughing, shortness of breath and fatigue and died a short time later. Pathological examination revealed that the lungs were severely damaged by inhalation of the metals. (Washington State Department of Labor and Industries, 2005).

Sources

https://nl.wikipedia.org/wiki/Thermisch_spuiten

Antonini, JM, McKinney, WG, Lee, EG, & Afshari, AA (2020). Review of the physicochemical properties and associated health effects of aerosols generated during thermal spray coating processesToxicology and Industrial Health, 0748233720977975. (abstract only)

Hériaud-Kraemer, H., Montavon, G., Coddet, C., Hertert, S., & Robin, H. (2003). Harmful risks for workers in thermal spraying: a review completed by a survey in a French companyJournal of thermal spray technology12

Washington State Department of Labor and Industries (2005) How to Protect Workers While Thermal Metal Spraying, by Safety & Health Assessment & Research for Prevention (Report # 69-3-2005). Tumwater, WA: Washington State Department of Labor, February 2005.

Read also

What is thermal spraying?

Thermal spraying and exposure