Personal Protective Equipment for Respiratory and Hearing Protection in Occupational Health and Safety and Their Compliance Tests

Personal protective equipment (PPE) ranks last in the hierarchical approach to risk assessment. While PPE is perceived as providing worker protection when worn, improper use or incorrect selection means PPE fails to deliver expected protection.

To prevent such risks, fit testing becomes essential. In developed countries like the United States, occupational health and safety requirements make fit testing mandatory and serve two purposes. The first is to determine whether the selected PPE is anatomically suitable for the individual. The second purpose is to verify that the selected PPE is being worn by the worker in accordance with instructions. Fit testing for respiratory and hearing protection has been developed and technologically advanced to facilitate easier understanding and interpretation by both the worker and the test operator. Fit testing was first made mandatory nationwide in the United States through OSHA regulation 1910.134. The United Kingdom followed the American example and made fit testing mandatory nationwide through HSE protocol 282/28, which drew from OSHA 1910.134. When the United States and United Kingdom enacted their initial legislation on fit testing, they established the requirement that merely wearing personal protective equipment is insufficient—employers must test whether PPE fits workers properly and maintain records of these tests. The regulations require that fit tests be repeated annually, serving both as a reminder to workers and as documented proof that practical training in the proper use of personal protective equipment has been conducted through fit testing. Following the United States and United Kingdom, New Zealand made fit testing mandatory through standard AS/NZS 1715:2009, while France requires fit testing for workers who will handle asbestos. In countries where fit testing is mandatory or recommended, fit tests are generally conducted before the worker begins employment and are recorded. During recording, the name of the test operator, the worker's name, date, the fit test method applied, which personal protective equipment was used, and the test result must be documented, with the report signed in wet ink. Fit testing may be conducted for new employees, workers returning from extended absence, those who have suffered workplace injuries, those reaching periodic training dates, those changing PPE, and those with complaints or concerns about PPE. Although Turkey has no directive, standard, or regulation concerning fit testing, companies originating from the United Kingdom and United States in particular conduct fit testing according to their internal procedures.

Respiratory fit testing is conducted to identify particles escaping through the gap between the mask and the face. Respiratory fit testing must be performed particularly on negative-pressure masks such as dust/particle masks and reusable masks. Fit testing is recommended for the following reasons:

• Due to anatomical differences among individuals, no single mask fits every person's face equally well. • For reusable masks, fit testing can be applied to determine which mask size is appropriate for the individual's face. • When mask user manuals are examined, they typically state that bearded and mustachioed persons should not use the masks. Fit testing can be applied to demonstrate how beards and mustaches reduce mask protection levels. • Fit testing can be applied to demonstrate how protection levels are affected when masks are not worn as specified in the user manual. Respiratory fit testing can be performed using two different methods. The first is qualitative, the second is quantitative fit testing. Qualitative fit testing is a subjective method. It depends on the worker's taste threshold. There are two solutions—sweet and bitter—which are aerosolized and converted to aerosol form. In quantitative fit testing, objective interpretation is possible using electronic equipment. In this method, a special probe is attached to the mask. By means of this probe, the device counts particles present in the air inside and outside the mask numerically and calculates their ratio. This ratio is called the "fit factor." Each mask type has a separate fit factor value. By checking this value against the list, the report indicates whether the individual passed the test. Using similar logic, hearing protection fit testing can also be performed. In some individuals, even the canal structure of the right and left ears can differ. The main problem with earplugs is that individuals generally do not know the dimensions of their ear canals, and errors are commonly made in the proper insertion of earplugs. For this reason, hearing protection fit testing plays a very important role.

Hearing protection fit testing is a test method performed with electronic equipment, providing the worker with specially-probed earplugs. A microphone is placed in the specially-probed earplug, and another microphone outside measures sound.

Noise at 7 different frequencies is transmitted using the device, and software displays the amount of noise reduction achieved separately for the right and left ear on the screen. Based on these results, the suitability of the protective equipment is verified by considering the worker's insertion method and/or ear canal structure along with the noise level in the work environment. According to the results of a hearing protection fit testing study conducted in the United States, 70% of workers achieved proper protection on the first test, while 17% of workers achieved the correct result upon retesting with retraining. An 11% group had to attempt fitting with a new earplug. A 1.5% group was informed that their ear canal structure was incompatible with earplugs, and that they should use earmuffs as their hearing protective equipment. Mirey Bonfil Technical Coordinator Occupational Safety Department 3M Türkiye