As indicated in our last two posts, Carbon Monoxide (CO) is a concern for firefighters, but what can we really do about it? It is also worth noting that high concentrations of CO may not be present.
Most firefighters know and except that it is impossible to eliminate exposure to Carbon Monoxide unless you choose to self contained breathing apparatus (SCBA).
Wearing SCBA in a bushfire application is not considered to be ‘reasonably practicable’ so the next best thing is to reduce your exposure and make use of filtration products that will remove harmful particles and improve your comfort levels.
Fatigue management is an important part of the reduced exposure process by allowing time for your body to recover from lower levels of CO exposure.
Fire decomposes or breaks down materials. The composition of these decomposed products will vary depending on:
- The composition of the burning materials – this can be from many sources.
- The ventilation conditions – poor ventilation reduces the available oxygen and changes the makeup of thedecomposition products.
- The temperature of the fire.
- Burning produces particles as well as gases and vapours. The gases can often include irritant gases likehydrogen chloride and acrolein.
Smoke is defined in AS/NZS1715:2009 as being carbon or soot particles or tarry droplets less than 0.1 micrometre in size and suspended in air, which results from the incomplete combustion of carbonaceous materials such as wood, coal, oil or paper. Normally, the combustion process that produces smoke also produces gases.
Respirators for Bushfires
Only SCBA (Self Contained Breathing Apparatus) is suitable for all the possible contaminants that can be released by fires in all situations.
SCBA is normally considered unsuitable for bushfire fighting because:
- The air in the cylinders does not last long enough to effectively fight bushfires.
- The cylinders are too heavy for use in high temperatures for long periods with a heavy workload.
- Outfitting and training hundreds of volunteers with SCBA would be too costly and difficult to organise.
- Maintenance – supplying hundreds or thousands of air cylinders when staff workloads are stretched, and transport is difficult would be a logistics nightmare
Air Filtering Respirators for Bushfires
Respirators with filters will remove some but not all of the fire products from the air. There is no filter capable of filtering every substance. Some considerations when using air-filtering respirators for bush fire fighters include:
- Are you expecting high levels of carbon monoxide or oxygen deficient conditions? If so, only SCBA should be used.
- Are you expecting inhaled particulate contaminants only? If so, use of a P2 rated filter is recommended for thermally generated particles (AS/NZS1715).
- If comfort and reduction of irritation is the primary concern, there is a variety of disposable and reusable air filtering respirators. Each type has advantages and disadvantages in specific applications. By capturing the smoke particles and some of the off gases, irritation from smoke inhalation can be significantly reduced.
- One option is to use half facemask filters. An added layer of carbon can help absorb nuisance levels of organic vapours and acid gases.
- Using full face respirator filters will provide even higher levels of respiratory and eye protection. Class P3 particulate filters can be added for protection against some toxic or highly irritant particulates (when worn with a full face respirator).
There are many brands and products on the market that could be used to improve the safety and comfort of our firefighters.
One example is the Fair Air mask. Around 500 NSW RFS brigades have previously purchased Fair Air masks using their own funds.
The manufacturer of the Fair Air mask says that the Fair Air Mask is:
- Highly fire resistant (the only respirator certified to ISO 9151 and ISO 15025).
- Removes 100% of PM2.5 smoke particulates (P2s only remove about 94%).
- Easy to talk through.
- Works with beards and other facial hair.
- Can be put on quickly without removing helmet.
Sets for firefighters come with a spare filter for use while washing the other, and cost a fraction of any P3.
Designed by a former ACT volunteer firefighter, Mike Taylor, they are made in regional Victoria.
The key to managing exposure to carbon monoxide is to use SCBA when the situation calls for that level of protection, use filtrations systems as appropriate and ensure that you take some fatigue management time off (away from the fire) so that your body can recover.
If you are working on the fireground and you are getting a headache or not feeling well, remove yourself from the smoke as soon as possible.
If the use of a half face or full face filtration systems improve your comfort level, then those options should be afforded you.
The VFFA fully supports a review of respiratory protection options available to all firefighters. This must not be held back until after this fire season.