Let us now take a closer look at respiratory protection. The purpose of a respirator is to protect you from the inhalation of infectious aerosols – for example mycobacterium tuberculosis. A respirator should only be used if needed. First, you should always use good laboratory practices to not create any infectious aerosols. If that is not possible, try to contain the infectious aerosol using an engineering control, such as a biosafety cabinet. Respirators should be used for protection only when engineering controls cannot contain the hazard at the source. For example, when working with animals outside of containment or in the field. Follow the link shown (https://www.youtube.com/watch?v=6qkXV4kmp7c) to watch a video that will introduce you to respirators in health care settings.

Remember, surgical masks are not respirators. Surgical masks are simply a barrier to stop large droplets from exiting from or landing on the user. Some people get them confused and think that a surgical mask is giving them protection from infectious aerosols, when it’s not. Follow the link shown (https://www.youtube.com/watch?v=ovSLAuY8ib8) to watch a video that will show you the difference between a surgical mask and a respirator.

If you determine that you need respiratory protection, based upon your risk assessment, you have some options. Respirators come in wide variety of shapes, styles and provide varying degrees of protection against infectious aerosols. Your choices of respiratory protection are basically half mask paper or elastomeric, powered air purifying respirators, or full facepiece elastomeric respirators. Air supplied respirators are beyond the scope of this course and will not be discussed. Each style of respirator is used under different circumstance and provides a different assigned protection factor or APF. This is the degree to which the respirator will protect the user from the airborne contaminant. For example, a respirator that provides an APF of 5 will reduce the contamination in the air to one fifth the concentration of the contaminant. A half mask respirator gives you an APF of 5, a powered air purifying respirator has an APF of 25, while a full-face elastomeric respirator provides a protection factor to 50. To learn more, visit the OSHA website shown https://www.osha.gov/sites/default/files/publications/3352-APF-respirators.pdf.

The half-mask or half-face respirators are the most common and least expensive. Examples include the paper N95 or KN95 masks and the painters half face mask with cartridges. The N stands for non-oil resistant, while the 95 means it will filter out 95% of particles of a specific size. You can also get N99 and N100 filtering face masks. The paper filtering face piece respirator will not prevent odors or gases from being inhaled. If you need to protect against gases or vapors a half-face or full-face elastomeric respirator with the appropriate cartridge needs to be used. If the user cannot wear a half-face or full-face respirator because they have facial hair, then they will need to use a loose-fitting, powered air purifying respirator. If there a gases and irritating vapors in the air a full-face respirator with the appropriate cartridge should be used to protect the eyes. Follow the link shown (https://www.youtube.com/watch?v=u_Dovk_khLw) to watch a video that will show you more about respirator types.

All respirators work by filtering the air you breath in and removing most of the infectious aerosols. If the air you breath in goes around the filter, then no filtering or protection occurs. Therefore, if you choose a tight-fitting respirator, it must be tested to ensure no air leaks around the sides. This is called fit testing and should be done in a prescribed manner with test equipment. Follow the link shown (https://www.youtube.com/watch?v=D38BjgUdL5U) to watch a video about respirator fit testing. If respirators are needed, there should be a comprehensive written respiratory protection program. A medical evaluation for the people using them is also required, because respirators put an extra strain on pulmonary function. Follow the link shown (https://www.youtube.com/watch?v=0PAuHfdVimk) to watch a video about medical evaluation for respirator users. If you are using a tight-fitting respirator, fit testing, and training on how to use it must also be provided Respirators also need maintenance and care on a regular basis in order to function correctly. Follow the link shown (https://www.youtube.com/watch?v=CnF05owDxTI) to watch a video that will show you more about respirator use and maintenance. Everybody should be made aware of the limitations when it comes to wearing respirators at the workplace. In the US there are a lot of regulations regarding respirator use. Do you know what regulations are in place in your country regarding respirator use?

In the next lesson we will look at the proper donning and doffing procedure for PPE.