Protecting workers from solid particle hazards

Solid particles are commonly referred to as “dust”. Why is this material harmful to humans?

SM: Exposure to various dust types, including Polychlorinated biphenyls (PCB) dust, mineral and chemical particles, and powder coatings, can lead to health issues, including skin irritation, respiratory diseases, cancers, and even death.

From an occupational health perspective, dust is categorised based on its physical and chemical properties that determine its potential health impact. There are three categories: inhalable dust, thoracic dust, and respirable dust. Inhalable dust refers to larger-sized particles, most of which will be filtered out in the nose and throat. Thoracic dust refers to the smaller-sized dust particles that can reach the lungs. Finally, respirable dust is small enough to be inhaled deeply, penetrating the gas-exchange region of the lungs.

What are the most common sources of harmful dusts?

Common sources of harmful dusts include industrial processes like manufacturing, construction, mining, and quarrying. Activities like grinding, cutting, drilling, and sanding can generate dust and other harmful particles. Additionally, agriculture, woodworking, vehicle exhaust, and household dust can contribute to dust exposure.

Are dust hazards easy to identify?

It depends. While some dust is visible, it can also be microscopic. Accurately measuring airborne particle concentrations requires specialised equipment and expertise. Variability in exposure over time and across different tasks adds to the challenge for HSE managers.

How many workers are affected by workplace respiratory diseases?

Nearly 3 million people globally die each year due to work-related causes, according to the International Labour Organization (ILO)¹. Of these, a large portion are attributed to workplace respiratory diseases, which, along with circulatory diseases and malignant neoplasms, are counted among the top three causes of work-related deaths². Echoing this sentiment, the World Health Organization reports that workplace exposure to air pollution including particulate matter, gases, and fumes were found responsible for 450,000 deaths³.

The EU-OSHA Workers’ Exposure Survey (WES) on cancer risk factors in Europe is working to address the lack of data surrounding this threat. Initial findings suggest that there is an increased risk for workers in micro or small-sized workplaces compared to medium-sized or large workplaces and for those working over 50 hours a week⁴.

What role does protective clothing play in preventing dust exposure?

It’s of paramount importance in preventing particles such as asbestos and polychlorinated biphenyls (PCBs) from entering the human body, particularly through skin contact. However, HSE managers need to make the right PPE choices, or workers may become more exposed to solid particles. Reusable workwear, for example, can inadvertently spread hazardous solid particles, exacerbating exposure risks during removal.

What special properties should HSE managers look for when selecting protective clothing for protection against dust hazards?

Standard protective overalls are ineffective against solid particle hazards as they are made from woven materials that allow dust particles to pass easily through the holes. Garments made from special, non-woven materials with advanced barrier properties are necessary to provide superior protection against even the smallest airborne particles. For example, DuPont Tyvek material is a non-woven fabric of spun polyethylene fibers. It offers superior protection against airborne particles as small as 1-2 μm.

Garments should also have good tear and abrasion resistance and a smooth surface to prevent particles from adhering to the material. Antistatic treatments can help in this regard. Look for garments that have taped seams and protective flaps over the zippers and fasteners, which offer added protection from particle penetration. Check that there is a good elasticated seal at the wrists and ankles and that the garment is fully compatible with other PPE such as masks, goggles, and gloves.

Are there any regulations governing protective clothing choices?

Yes. Regulation (EU) 2016/425 mandates the use of Category III Type 5 protective clothing for protection against solid airborne particles. These garments, such as chemical protective coveralls, must meet EN ISO 13982-1 standards and pass a penetration cabin test to ensure they effectively prevent dust penetration. The test involves exposing the garment to a controlled dust cloud and measuring the amount of dust that penetrates the material. To pass the test, the garment must achieve specific inward leakage limits.

HSE managers must identify complex hazards, accurately quantify exposure levels, and familiarize themselves with the specific barrier properties required. It's important to stress that while Type 5 protective clothing offers a minimum level of protection against solid particles, it's not completely impervious. To achieve the best protection for their application, HSE managers should consider the specific penetration rates of garments. This information should be stated on the manufacturer’s product sheet.

Finally, what additional steps can HSE managers take to further safeguard workers from solid particle hazards?

Educating workers about the risks of invisible hazards can be challenging, especially for those working with seemingly benign substances, such as flour dust. Ensuring workers understand the risks and follow safety protocols is equally as important as selecting the right level of protective garment.

Taking a holistic approach by regularly reinforcing safety messages and providing comprehensive training, with a focus on correct donning and doffing procedures, can significantly reduce the risk of exposure to hazardous substances.

Collaborating with reputable PPE manufacturers like DuPont, which offer training resources, can help to further strengthen worker education, and promote best practices in personal protection.

Steve Marnach is EMEA training manager and specialist critical environments at DuPont Personal Protection. For more information, visit www.dupont.com

DuPont has published an E-Guide to assist HSE managers in understanding, assessing, and mitigating solid particle risks, and to provide guidance on selecting appropriate protective garments for workers. The E-Guide can be downloaded here:  

References
1 https://www.ilo.org/resource/news/nearly-3-million-people-die-work-related-accidents-and-diseases
2  https://www.ilo.org/resource/news/nearly-3-million-people-die-work-related-accidents-and-diseases 
3 https://www.who.int/news/item/17-09-2021-who-ilo-almost-2-million-people-die-from-work-related-causes-each-year
4  https://osha.europa.eu/en/publications/occupational-cancer-risk-factors-europe-first-findings-workers-exposure-survey