Employees on your farm may be exposed to a wide variety of respiratory hazards such as vapors, moulds, dust and gases. It is important to consider what respiratory hazards may be present on your dairy and then determine what controls will offer the best protection to your employees.
Some of the most common examples of respiratory hazards include gases such as hydrogen sulphide, methane, ammonia and carbon dioxide, which are produced from decomposing manure and can be present in high concentration in manure storage areas. Areas with limited or deficient oxygen levels are another hazard.
Examples may include manure storage areas, silos, grain bins or underground pump areas. Toxic fumes or vapors from hazardous chemicals such as formaldehyde – used for footbaths – and other chemicals that may be used for cleaning, treating animals, equipment maintenance and controlling pests are a danger to those nearby. Dust from lime or other hazardous products and mould spores produced by microorganisms which grow in baled hay, stored grain or silage are also respiratory safety concerns.
There are often three options to consider when determining the best controls for respiratory hazards.
- The elimination or substitution of the hazardous substance. An example of this is using a less toxic chemical for cleaning.
- Using engineering controls to reduce the exposure. Mechanical ventilation is a great example of this type of control.
- Personal protective equipment (PPE) such as a personal respirator. Using PPE may be an important part of controlling respiratory hazards on your dairy, but it is important to understand the limitations of PPE and ensure they are used properly when needed.
By being aware of the potential hazards and using recommended personal protective equipment (PPE) for each hazard, producers can reduce their risk of developing health conditions.
Ventilation
The purpose of most ventilation is to provide fresh air, control heat and moisture, and to remove odours, gases and other respiratory hazards. Ventilation should work to distribute fresh air evenly throughout the barn and prevent contaminates from building or remaining in specific areas.
Throughout your workplace, you may rely on natural ventilation, mechanical ventilation or a combination of both. Natural ventilation relies on the natural forces of wind to function properly; unfortunately, the effectiveness of natural ventilation can vary throughout the year and there is a risk of “dead spots” where air is not circulating sufficiently.
Mechanical ventilation systems can range in complexity – and are most often made up of fans that move the air and inlets that allow fresh air to be brought into the area. Large ceiling fans may also be part of your ventilation system and may help to move air throughout the work area.
Local exhaust and ventilation systems may also be used for specific tasks such as welding or equipment maintenance.
Whatever type of ventilation system is used, you must evaluate the area to determine if the ventilation is adequately reducing the respiratory hazards that may be present.
Respiratory protection
Respirators can be used to prevent individuals from inhaling airborne contaminates. Respirators should be used if other hazard control methods aren’t practical or possible. They are not the first choice because they do not eliminate the hazard and can be unreliable if not fitted, worn and maintained properly.
When choosing the type of respiration device to be used in your workplace, you must first determine the type of hazard and measure the exposure. Refer to the Safety Data Sheet for any chemicals or other substances used. Types of hazards typically fall into three basic categories, including particulate contaminants such as dust and fumes, gases/vapors and oxygen-deficient atmosphere.
The most common respirators used on a dairy farm include half-face respirators or full-face respirators with either filters or cartridges or a combination of both. One of the most important parts of selecting the right respirator is to ensure you are using the right filter or cartridge for the substances present. Keep in mind, when you are using a half-face respirator, you may also be required to wear goggles if there is a risk of eye injury from the exposure. Again, check the SDS for more information.
Respirator fit
Respirators can only work effectively if they fit correctly. A respirator that does not fit appropriately may allow contaminants to be inhaled. The user must adjust the facepiece and the straps for a good seal between the respirator and your face. If your exposure exceeds the allowable limit, a fit test must be completed by a qualified person following the standards set out in CSA Standard.
Each time you use a respirator, you must complete positive and negative pressure seal check, which is a quick check performed by the wearer. This helps confirm the respirator is properly seated to the face.
Negative pressure seal test
- Block the filter inlets with the palms of your hands. Gently inhale and hold for five to 10 seconds.
- The mask should collapse slightly but not allow air into the facepiece.
- If the facepiece remains collapsed, there are no leaks.
- If there’s a leak, readjust the straps and check again for proper fit.
Positive pressure seal check
1. Block the exhaust valve with your hand. Hold your hand on the valve and gently exhale for five to 10 seconds.
2. The mask should expand outward slightly, but it should not allow air to escape.
3. If the facepiece remains expanded, there are no leaks.
4. If there’s a leak, readjust the straps and check again for proper fit.
Inspections, maintenance and storage
To ensure your respirator will work properly, you must do a quick inspection before each use. Look for defects, cracking and areas that are wearing out. If parts are damaged or deteriorated, they must be replaced before the respirator is used again.
Check the facepiece, straps, buckles and valves. Ensure the correct cartridge, canister or filter is used and ensure they are clean and not clogged. Replace filters and cartridges as needed or as per expiry date.
To clean the respirator, remove the cartridges and filters, immerse the facepiece in warm water with a mild detergent, clean with soft brush or sponge, rinse in warm water, then air dry.
Store in a clean area away from dust, chemicals, sunlight, heat, extreme cold, excessive moisture, tools and equipment. Respirators must be placed in plastic bags or airtight containers when not in use.
