Michael is a seasoned construction worker that has been on many jobs for his company over the last seven years. Often, Michael is given the task of abrasive blasting, which uses compressed air or water to direct a high velocity stream of abrasive material (usually crystalline silica) to prepare surfaces for paint, or to clean surfaces for various reasons. When Michael blasts surfaces, he generally doesn’t wear respirators and often ends up inhaling some of the crystalline silica at the worksite.
Last week Michael went to see his doctor, Carol, for a periodic checkup and told her that he noticed he seems to feel like he has to work at breathing sometimes and it seems to be happening more frequently. Carol ran some tests and got back in touch with Michael the next day. Carol was saddened that she had to tell Michael he has accelerated silicosis. In simple terms, accelerated silicosis is a chronic disease in which the silica dust causes areas of swelling in the chest lymph nodes and lungs which causes difficulty breathing. Depending on the type of silicosis, a person may live many years or only a few months. Michael may suffer from complications such as lung infections, progressive massive fibrosis, and even respiratory failure. There are treatments for Michael that can help to ease his symptoms and address infections, but accelerated silicosis cannot be cured. Abrasive blasting has permanently impacted Michael’s life.
What could Michael and his employer have done to eliminate the hazards Michael was facing while blasting surfaces with abrasive materials? Before asking Michael to blast surfaces, Michael’s employer should have identified the hazards involved and taken the necessary action to eliminate the hazards. To do this Michael’s employer could have used the hierarchy of controls.
Simply put, the “hierarchy of controls” is a strategy the employer can use to eliminate or reduce the hazards their employees face in the workplace. ANSI Z10-2005, Occupational Health and Safety Management Systems, encourages employers to use the following five hazard control strategies.
The employer should determine whether abrasive blasting is even necessary. Can the employer get the same results using methods that are not potentially hazardous to their employees’ health?
- Can the employer substitute an abrasive blasting material that is less toxic, such as:
- plastic bead media;
- dry ice;
- sponge; or
- sodium bicarbonate (baking soda)?
- to reduce dust can the employer substitute abrasives that can be delivered with water (slurry)?
The employer, to the greatest extent feasible, should eliminate hazards or reduce their employee’s exposure to hazards by thoughtfully designing their work environment (tools, machinery, facility, etc…) and even the job itself.
Isolation and Containment
- isolate the workers from the blasting operation using curtain walls and barriers
- for smaller operations use blast cabinets or blast rooms
- for non-enclosed blasting operations use restricted areas
- do not let co-workers near the blaster
- capture dust using exhaust ventilation systems in containment structures.
The employer should adjust work schedules and design safe work practices into the employee’s job procedures.
- Do not use compressed air to clean as this will stir up dust in the air.
- Ensure tarps and other equipment on the worksite are cleaned and decontaminated.
- Blasting should be scheduled when the least number of workers are at the worksite.
- Try not to blast in windy conditions in order to reduce the spread of hazardous materials.
- To minimize the accumulation of toxic dusts use wet methods or HEPA filtered vacuuming to perform routine cleanup.
- Eating or drinking in blasting areas should be prohibited.
- Provide wash stations to ensure workers regularly wash their hands and face and before eating, or drinking.
- Before eating, or drinking workers should vacuum or remove contaminated work clothes.
- Provide accommodations for end-of-shift showers and change areas with separate accommodations for street clothes, protective clothing and equipment.
- Do not allow contaminated equipment and clothing in the clean-change area.
Personal Protective Equipment (PPE)
To shield the worker from rebounding abrasive, an abrasive-blasting respirator must cover the worker’s head, neck, and shoulders. Only respirators approved by NIOSH to provide protection from dusts produced during abrasive-blasting operations should be used by workers (Type CE NIOSH-certified blasting airline respirator with positive pressure blasting helmet).
Support personnel assisting with the cleanup and other related activities may need respiratory protection as well.
The employer should also provide the following PPE:
- hearing protection
- eye and face protection
- aprons (or coveralls) and leather gloves that protect to full forearm
- safety boots or shoes
Worker Training and Hazard Communication
Along with the hierarchy of controls it is always important for the employer to ensure their employees are trained properly and understand the hazards associated with each task they perform, including abrasive blasting.
- Provide training to abrasive blasters and support personnel on, how to use controls, blasting health and safety hazards, safe work practices, personal hygiene practices and the use of respirators and PPE.
- Manufacturers must ensure the safety data sheets (SDS) include the appropriate health hazard information concerning the blasting materials per OSHA’s Hazard Communication standard (29 CFR 1910.1200).
- Obtain and read the manufacturer’s SDS for health hazard information concerning the abrasive blasting material you are using.
OSHA, (2013), OSHA FactSheet, Protecting Workers from the Hazards of Abrasive Blasting Materials. Retrieved from https://www.osha.gov/Publications/OSHA3697.pdf
American Lung Association, (2014), Understanding Silicosis. Retrieved from http://www.lung.org/lung-disease/silicosis/understanding-silicosis.html