Reducing Silica Exposure in Manufacturing
To prevent exposure to silica dust, you'll need more than a simple mask. Find out what controls you can put in place to keep your workers safe.
Whenever you touch a piece of quartz countertop, let sand run between your fingers, or brush your teeth, you come in contact with silica.
It's one of the most common elements in our physical environment, a chemical pairing of silicon and oxygen, known as silicon dioxide. From a health perspective, it has much in common with salt and with water: it contributes to your health, yet too much of it can be fatal.
The dangers of silica have to do with its physical makeup, especially as it's found in places like manufacturing plants. Silica can turn to dust that can enter the body through the lungs.
The Dangers of Silica
Although silica can be a beneficial food element and an antioxidant when ingested in the correct amounts, the effects of exposure to airborne silica can be dangerous. As microscopic particles of rock penetrate the internal organs, they can cause irritation and permanent damage, including:
- Lung cancer
- Impaired kidney functions
Silicosis, as the name implies, results directly from exposure to silica. It is characterized by inflammation, scarring, and the development of lesions in the lungs. While it might sound like a modern condition to those who aren't familiar with it, it has been around since the Ancient Greek and Roman eras – potters, masons, sculptors, and others who worked with stone all did their work while breathing air laden with silica dust.
The other illnesses are not directly caused by silica. Rather, lupus, arthritis, and kidney function impairment result from autoimmune diseases that are triggered or aggravated by the presence of silica dust in the body.
Common Sources of Exposure
For the average person, silica ingestion is minor – on par with pollen and other natural and human-made contaminants. Given that most of the Earth’s crust is composed of silica, it is part of our natural environment and our bodies are able to process it accordingly. Even people who take too much by mouth, for example by taking too many vitamins, will simply flush out the excess through urination.
There are, however, many trades and workplaces in the manufacturing sector where exposure to silica poses a significant risk. Most of these occur wherever stone or soil is impacted and creates dust, especially when quartz is present. It takes only a very small amount of airborne silica dust to be dangerous. Special care to reduce exposure needs to be taken with anyone who:
- Works with raw materials with a high quartz or stone content
- Manufactures high tech components that use silica as a base
- Engages in abrasive blasting
- Works with Portland cement
- Uses power tools (air hammer drills, saws, and grinders) on concrete and stone
- Works with asphalt, grout, concrete blocks, drywall, and even some types of paint
- Works with old materials like fire brick or insulation that might have degraded from a glassy to a crystalline state, through devitrification
The particles of respirable silica are 1/100th the size of a grain of sand, and they cannot be seen or smelled. Organizations like OSHA have established a permissible exposure limit (PEL) based on the amount of quartz detected in a sample of respirable dust, ranging from between 100 μg/m3 for pure quartz, to higher values when other particulates are also detectable. This requires sampling and detection tools and some calculation ability, and very often the difficulty in performing or understanding the calculations contributes to the danger.
It has also been suggested that the current minimum threshold is still too high and should be adjusted to 50 μg/m3. Safety professionals overseeing workers who are exposed to levels above that range are encouraged to protect their workers from exposure, even if the levels are considered permissible by OSHA standards.
Adequate protection and exposure prevention is essential. Since dust tends to travel very easily through the air from ground level through to ventilation systems and smokestacks, this applies not just to manufacturing workers. Employers should also take measures to prevent exposure to people in a wider radius, including residents and business owners within the area.
Mitigating Silica Exposure
Proper management of exposure risk has numerous levels.
Use of Respirators
Since breathing is the primary source of silica-based illnesses, face masks are sometimes assumed to provide sufficient protection. Silicosis experts, however, attest that paper masks are ineffective.
Similarly, respirators should only be used in conjunction with engineering and environmental controls, not as a primary tool. A job site must attain complete physical control of the environment, and if that is not sufficient to bring the particulate count to an acceptable level, then respirators, including sufficient training according to NIOSH standards, is obligatory.
To control the distribution of silica particulates, job sites must incorporate:
- Adequate ventilation
- Dust control through wet processes, such as water sprays and water delivery to cutting blades
- Use of enclosures to trap particulates in a confined area
- Vacuum collection systems that pull particulates directly away from the work surfaces and machinery
- Prohibition of activities that encourage dust, such as dry sweeping and driving vehicles quickly through high dust areas
Exposure risk can also be mitigated by using silica replacements in activities like sandblasting as well as manufacturing processes. A wide selection of alternatives, ranging from steel to organic products can be used as abrasives, adhesives, or components.
Finally, but equally importantly, there are administrative controls, which include:
- Developing and communicating an exposure control plan
- Enforcing awareness of operations that create crystalline silica exposures as well as preventative steps and practices
- Instituting hygiene restrictions, such as prohibiting food or drink in work areas, providing emergency shower facilities, eyewash stations, and change rooms with shower and vacuum facilities for complete changes and cleaning of clothing
- Discouraging automatic habits like brushing dust away from the body
- Discouraging the growth of mustaches and beards that reduce respirator effectiveness
- Discouraging smoking, which compounds lung damage and health risks
- Encouraging awareness and adherence to all health and safety regulations, as well as opportunities to report dangers and procedural failures
- Implementing exposure monitoring and health screening programs
- Ensuring employees’ physicians are provided with a copy of the Physician’s Alert for Silicosis for adequate treatment and avoidance of misdiagnoses
- Establishing stringent recordkeeping practices
The dangers posed by silica dust are severe and must not be ignored. Manufacturing workers, contractors, or managers who have concerns should turn to their local health and safety rep for guidance and enforcement.
More from AD Safety Network
- When should you consider using custom molded earplugs?
- At what height do falls become deadly?
- Who should be responsible for rescuing fallen workers?
- What kind of training do loading dock workers need?
- How often should I inspect a loading dock?
- How is wind chill calculated?
- What is the difference between occupational safety and process safety?
- Why should rubber insulating gloves be tested?
- What happens if I tie off at the foot level with a personal SRL?
- Why is testing with a NAIL4PET accredited lab important?
- What kind of face protection do I need when using a chainsaw?
- What is the permissible exposure limit (PEL) for silica?
- What is silica and why is it hazardous?
- What is 'Table 1' and why is it so important?
- Video Q&A - What is a safety policy?
- What kind of fire extinguisher is best for your work site?
- How do I choose the right respirator and mask for working with silica?
- Can I wear fall protection equipment over my rainwear or winter gear?
- When do I need a cage ladder?
- What types of gloves protect your hands from hazardous chemicals?
- How come I still got hurt while wearing flame-resistant clothing?
- What dangers do workers face when working outside in the winter?
- How do I win over my most reluctant employees?
- What kinds of jobs should use disposable safety gloves?
- Is it true that safety shouldn't be a top priority?
- When are employers allowed to conduct drug and alcohol tests on their employees?
- How can I get employees more involved in the risk assessment plan?
- What are some of the indirect costs of accidents?
- How often do fire extinguishers need to be inspected?
- What is the best way to store rubber safety gloves?
- How much voltage protection is needed for safety gloves used in electrical work?
- What is the difference between a safety valve and a release valve?
- When do workers have the right to refuse to work?
- What is the most overlooked item when designing Lockout/Tagout (LOTO) procedures?
- What are some of the misconceptions about heat stress and what should we do to address them?
- What tools should I tether when working at heights?
- What types of gas should I watch out for when working in a confined space?
- How do you create a culture of safety in your workplace?
- What is the difference between industrial safety and industrial hygiene?
- Is it important to get PPE assessments by trained professionals?
- What is a fault tree analysis?
- What kind of respirator cartridge should I use?
- What are the safety benefits of a whistleblower program?
- What type of safety record-keeping and recording should we be doing?
- What makes a hi-vis safety vest ANSI compliant?
- Why is it important to have air sampling done to determine my PELs?
- What is the life expectancy of fall protection equipment?
- What are hot work and cold work permits?
- What are some basic fall protection rules that each of my workers need to understand?
- How much clearance do I need to safely use a Leading Edge SRL?
- What is the difference between an acute hazard and a chronic hazard?
- What’s the difference between a bump test, a calibration check, and a full calibration?
- Is there any legislation regulating lone worker safety I should know about before hiring?
- What kind of fire extinguisher and accessories should be kept on hand on a factory floor?
- What can companies do to reduce their lost time injury frequency rates?
- Video Q&A - What's your safety network like?
- Video Q&A - What are the 3 levels of safety?
- Video Q&A - How do you treat a near miss?
- Does body weight affect falls differently?
- What ages are most affected by falls?
- Why do workers take risks?
- What Is the Difference Between OHSAS 18001 and 18002?
- What is the difference between lost time injury and medical treatment case?
- What is the difference between occupational health and safety and workplace health and safety?
- What is the difference between occupational health and occupational safety?
- What is the difference between a lost time injury and a disabling injury?