Which type of filter does my respirator need?

Industrial applications and environments are all full of hazards, whether it’s trips, falls, bumps, and burns, or less obvious and in the air we breathe. In all instances, we put measures in place to remove the hazard or we change how we interact with a task in order to keep ourselves safe. Unfortunately, sometimes there just isn’t a way of completely avoiding these hazards, and so PPE must be worn to mitigate the risk. When it comes to using respiratory protection, knowing the right type of filter or cartridge that you need is critical, and can be the difference between being compliant, and realistically, life and death. In this article, we step you through a quick guide of what you need to know, so you can make safer decisions at work.

Please note: Filter types, definitions, and terminology can vary region to region. For the purpose of this article, we have used NIOSH certification and terminology.

Types of Filters & Cartridges

Particulate Filters: These are the most common type of filters available and have been designed specifically to only filter particulate hazards, such as silica dust. A filter's efficiency and the types of particulate matter it can withstand is determined by the composition of the filter. Based on this, a filter will be assigned a letter and number rating, i.e. N95, which you may be most familiar with.

The higher the number, the greater the filter efficiency. Your application will determine which filter rating you require, and this is governed by the Occupational Safety & Health Administration (OSHA).

Nuisance Filters: Some applications, depending on the materials you’re working with, can create smells that you may want removed. Nuisance filters utilize a particulate filter, but have an additional thin layer of activated carbon, which covers the surface area of the filter. The carbon binds onto any smells as they enter, neutralizing them before they can be breathed in by the operator.

Pictured above are the P100 Nuisance Odor filters for the Elipse and Integra respirators, showing the P100 filter media on one side in white, and the carbon layer in black on the other side.

Organic Vapor (OV), Acid Gas (AG), & Multi-gas Cartridges: Like the nuisance filter, these filters utilize carbon to adsorb or absorb the contaminants in the air. The properties of the hazard will determine what type of carbon is used. Multi-gas cartridges provide the most protection against a greater range of hazards. It’s important to note also, that because the carbon is activated, it has both a limited shelf life and an exposure threshold. If you are using this type of protection, it is essential that the exposure levels are measured as this will determine cartridge changeout schedule.

Pictured above are the OV/AG and Multi-gas cartridges available for the PX5 PAPR. Although they look similar the color on the labels indicates the hazards that filter can protect against. For example, yellow on the label indicates protection against Organic Vapors & Acid Gases.

Please note: None of these filters/cartridges remove carbon monoxide or change oxygen levels. If you are working in oxygen deficient areas, it is regarded as immediately dangerous to life or health (IDLH) and you need to use a respirator appropriate for that environment.

It’s important to always monitor your air quality to understand what your exposures are, and to work with an industrial hygienist to determine the correct type of respirator needed for your application.