Only you can protect your lungs.

Breathing comes naturally, it is something we do every second of every day. In fact, respiration is a vital trait we share with almost every living organism on the planet. Our lungs breathe in air and in turn fuels our body with the oxygen we need to survive. Our lungs perform like clockwork, an intricate well-oiled machine breathing in 8,000 - 9,000 litres of air each day that is required to oxygenate in the vicinity of 9,000 litres of blood that is pumped through the heart daily. At times we take our breathing and our respiratory health for granted, but the lungs are delicate vital organs that are vulnerable to airborne infection and a range of illnesses if not taken care of.

Respirator filters don't last forever...the importance of filter change.

In today’s industrialised society, there are many situations where workers need protection from airborne contaminants and the use of personal respiratory protection is essential. There are a variety of respiratory protection products available for various types and levels of exposure to airborne contaminants, and advice on their selection and use in Australia & New Zealand can be found in the following standard: AS/NZS 1715 “Selection, use and maintenance of respiratory protective devices”. The most broadly used are disposable and reusable air-purifying respirators that are powered by the wearer’s own breathing cycle and use a filter to remove contaminants from the inhaled air.

Disposable respirators, as the name states, are throw away items and therefore maintenance free. Reusable respirators, on the other hand, whether a half face or full face model do require some maintenance. Of particular importance in the maintenance regime are the filters. The filters don't last forever – and the most common questions from users are:

• How long will my filter last?
• Why do I need to replace the filters?
• When do I replace the filters?

These are all very valid questions and concerns, and although the answers aren’t always straightforward, the following information can be used as a guide to determine safe answers.

What types of filters are there?

Filters are available in a variety of options for both half and full facepiece respirators to protect against the multitude of airborne hazards such as particulates, gases, fumes and vapours. The correct filter to use depends on the hazards present in your work environment and the level of protection required. Examples of reusable respirator filter types and their applications are outlined below.

Particulate Filters
Protect only against particles i.e. dust, mists and fumes, aerosols, smoke, mould, bacteria and so on.

Gas & Vapour Cartridge Filters
Protect only against gases and vapours. There are different kinds of cartridge filters for different kinds of gases and vapours.

Combination Filters
Protect against particles, gases and vapours. Different combination particulate/cartridge filters are used depending on the type of gas or vapour present in the air.

How long will filters last?

Provided they are stored unopened in their original packaging, filters will be usable up to the expiry date indicated on the filter or the packaging. Once removed from their packaging, however, gas & vapour cartridges potentially can be used up to a maximum of 6 months, at which point they should be replaced, irrespective of the amount of use, as recommended by Australian/New Zealand Standard AS/NZS 1715. Once opened and in use, the service life of the filter varies as it depends on a number of factors, including; the quality and capacity of the filter, what it is filtering, type of filter and frequency of use - it does not have a fixed life-span as every work environment is different and it will vary according to the conditions of exposure.

Knowing how long a filter will last also requires users to have knowledge of their processes and workplace conditions. Determination of specific exposure information will allow firstly, selection of the most suitable product and secondly, creation of a relevant filter change schedule to provide workers with the information required to ensure they change their filters appropriately. This approach, aligned with good training and correct use of the product will help workers achieve the prescribed levels of respiratory protection and a safer workplace.

When not in use, it is important that your respirator and filters are kept clean and dry, and away from oil, sunlight and contaminated atmospheres to avoid deterioration. A storage container or bag that can be sealed, can be utilised for this purpose.

Why do I need to replace my filters regularly?

Once you are aware that filters don't last forever, it's easy to understand the importance of a filter change routine. If not changed regularly, undue physical burden will be placed on the worker and particulate filters and/or gas & vapour cartridges may not be providing any protection after they have reached their capacity. It's as simple as that. You are placing yourself at risk for serious lung diseases that may dramatically affect your quality of life, and in some cases, even death.

Particulate filters get clogged up and become harder to breathe through. Gas and vapour cartridge filters start to let contaminant through once their sorbents become saturated, this is called breakthrough. It's important that the selection of filters is carried out by a competent person with full knowledge of the respiratory hazards in the workplace.

When do I replace my filters?

Particulate Filters

Particulate filters rely on a number of capture mechanisms to trap particles within the filter media. As particulate filters load up with the contaminant, they may actually become a better filter, however, they also become harder to breathe through. AS/NZS 1716 uses a classification system to identify the different types of particulates these filters will capture e.g. P1, P2, P3.

Replace the particulate filters (there may be one or two) when:

• It becomes difficult to breathe comfortably (this timing will vary from individual to individual)
• The filter becomes unhygienic/dirty or physical damage occurs

Gas & Vapour Cartridge Filters

Gas and vapour cartridge filters rely on sorbent material to “soak up” the gas and vapour molecules. Typically the sorbent is carbon grain, which has been specifically treated. Depending on the chemical treatment of the carbon surface, this material will absorb different types of gases or vapours. AS/NZS 1716 uses a code/colour classification system to identify the different types of contaminants these treated carbon grains will capture, refer to the table below (also shows the colour for Particle filters).

The service life (i.e. how long it will last) of any gas and vapour cartridge filter is affected by many factors, some being: concentration and identity of contaminants, breathing rates, humidity levels, ventilation, temperature, carbon exposure time, etc.

Replace gas & vapour cartridge filters:

• When the expiry date stamped on the sealed packet has elapsed
• Once opened, the maximum use time is 6 months (even if not used). The carbon will absorb contaminants from the general environment
• When contaminant can be detected by smell or taste
• Or in accordance with your established filter change schedule

Combination Filters

As combination filters are products that combine a particulate filter with a gas & vapour filter, each of these components will fill up in use at a rate dependent on the exposures occurring during their operation and should be treated in the same manner as the particulate and gas & vapour filters mentioned above. The particulate filter component will fill at some point as described above and will then need changing. If it is a fixed part of the combination filter, the whole product needs to be changed. For the gas & vapour component, this also will fill at a rate according to the exposures and should be changed according to the conditions specified above.

Note: There are many gases and vapours used in industry where a gas & vapour cartridge will not be able to capture and hold the contaminant in question. In these instances, the use of air supplied respiratory equipment would be required. Be sure to confirm you have the correct respiratory protection for the contaminants you are working with.

Helping to protect your way of life.

At 3M we understand the importance of respiratory protection and are dedicated to improving worker safety, everyone should be able to work in an environment free from harm. The primary objective of any respiratory protection program is to prevent exposure to air contaminated with harmful dusts, fogs, fumes, mists, gases, smokes, vapours, or sprays, and in turn, prevent occupational illness. We have a wide range of reusable respirators and filter cartridges that can help protect against hazardous chemicals and particulates. We can also help you with your selection process, our free 3M™ Select and Service Life Software can help make selecting the appropriate respirators faster and easier. Just enter contaminants and their concentrations and the software analyses the data and profiles a record of your choices. The software can also help you estimate the service life of 3M™ Respirator Cartridges.

The information provided above is intended as a guide to assist you with 3M™ Cartridges and Filters used with your 3M™ Half or Full Facepiece Reusable Respirators. For additional information or specific advice to assist you with 3M Respiratory Products, e.g. choosing a respirator, fit testing, and when to change your particulate and gas & vapour cartridges, contact a 3M Safety Specialist or visit the 3M Centre for Respiratory Protection where you can explore step-by-step tools to ensure your respiratory protection is comprehensive and effective.