Read part 1 here.
Exposure to high levels of dust in cement production can potentially cause nose and throat irritation, while long-term exposure to dust containing crystalline silica can lead to lung disease (silicosis).
It takes a number of years of daily exposure before there is a risk of developing silicosis and it is typically seen in workers from industries where there is a significant exposure (e.g. quarries). One of the health risks from working in the quarry industry is that of exposure to this fine dust, which is found in almost all kinds of rock, sands, clays, shale and gravel, but products such as concrete and mortar also contain crystalline silica.
Silica is a natural substance found in most rocks, sand and clay and in products such as bricks and concrete. In the workplace these materials create dust when they are cut that may be fine enough to inhale and possibly lead to health issues.
Long-term exposure to silica dust is one of the most common occupational diseases and leads to conditions such as silicosis, chronic obstructive pulmonary disease (COPD) and lung cancer. In the most severe cases, developing silicosis as a result of breathing in silica dust can be disabling or even fatal. There are a number of actions an employer should carry out in order to keep workers safe. These include:
- Removing the risk by engineering it out of the process, if possible.
- Ensuring ventilation and/or extraction systems are put in place to clean or filter the air.
- If staff are working in a potentially hazardous environment, providing appropriate personal protective equipment such as respirators.
- Instructing and training employees in the proper use of the equipment and ensuring any face masks, half masks or dust masks fit correctly.
Lee Fenton, Industrial Sector Sales Manager at leading UK safety company, Arco, said: “In the UK, any industry where workers may be exposed to silica is subject to the Control of Substances Hazardous to Health Regulations 2002 (COSHH), which require the health risk to be properly assessed and then measures introduced to either prevent or control exposure to this risk. The results of the COSHH assessment will set out the ways in which the risk can be controlled and how they should be monitored, supervised and maintained.”
“PPE should always be used as a last resort, when other control techniques such as dust suppression or exhaust ventilation, cannot reduce the exposure sufficiently,” continued Williams. “It’s important to select the correct respiratory protection. As a minimum, the respiratory protection you use should provide an assigned protection factor (APF) of 20 for particulates. The specification for the type of respiratory protection needed will depend on the level of protection required by the risk assessment and the suitability for the task. For those exposed to silica dust over long periods (typically over 3 – 4 hours) or those carrying out physically demanding activities, a powered respirator system may be suitable. Its battery powered fan unit combines with a choice of headtop and filter to provide complete protection. For those exposed to silica dust for only short durations then a re-usable, half-mask solution, combined with a P3 filter will provide a safe and cost-effective solution.”
One of the most effective ways of protecting workers is through the use of disposable coveralls.
DuPont, a world leader in market-driven innovation and technological solutions, has supplied Europe with protective coveralls for the past 20 years. The company has recently added the Tyvek® Classic Xpert coverall to its catalogue, which has a superior level of protection in the Type 5, 6 categories. All protective coveralls for this industry, including Tyvek® coveralls, are tested using 0.6 µm of dust to ensure those exposed to cement will be adequately protected. The test has revealed that the Tyvek® coverall offers a 99.2% holdout to the dust challenge. When comparing this to the size of cement dust (3 – 100 µm) the coverall provides a considerable level of protection.
PPE can be rendered ineffective if incorrect donning and doffing procedures are used.
Ian Samson, Chemical and Thermal Consultant for DuPont EMEA, commented: “The Tyvek® Classic Xpert coverall will protect the skin against the abrasive and irritant particles of cement dust; however it will be rendered ineffective if incorrect donning and doffing procedures are used. A recent example of this is when workers on a large construction firm began experiencing irritation and burns in the groin area, despite wearing the correct coveralls. Through investigation it became apparent that the workers in question were not taking footwear off when putting on their coveralls. By not following the correct donning and doffing procedures, cement dust was being deposited inside the coverall and reacting against the skin as the worker began to sweat. Recognising this common problem, we have redesigned the Tykek® Classic Xpert coverall packaging to display simple pictograms that illustrate the correct donning and doffing procedures and offer tailored training to educate wearers. By following these simple steps, users can be assured of the performance of the garment.”
Another occupational health hazard that the cement industry frequently encounters is the buildup of static energy, which when released can cause sparking and explosions. Companies must ensure that all equipment is earthed to avoid the buildup of static energy and this extends to personal protective clothing. Tyvek® coveralls are treated with an antistatic agent both inside and out and will aid with the dissipation of static charges as long as the coverall is worn with other appropriate PPE that is earthed.
For examples of best practice see CSI’s ‘Health and Safety in the Cement Industry – Examples of Good Practice,’ which can be found at www.wbcsdcement.org.
This is an abridged version of the full article, which appeared in World Cement’s May 2014. Subscribers can view the full article by logging in.
Read the article online at: https://www.worldcement.com/europe-cis/28042014/safety_in_the_cement_and_concrete_industry_part_2_94/