What are the specific steps required to properly fit a variety of earplugs and earmuffs to different users and to ensure that they achieve their optimal attenuation levels?
Proper fitting of hearing protection devices (HPDs), whether earplugs or earmuffs, is crucial to ensure they provide the intended noise attenuation and protect workers from noise-induced hearing loss (NIHL). The fitting process needs to be tailored to individual users due to variations in ear canal size, shape, and personal preferences. Here are the specific steps required for fitting various earplugs and earmuffs:
For Earplugs:
1. Selection of Appropriate Earplug Type and Size: Earplugs come in various types and sizes. Foam earplugs are usually one-size-fits-most but need to be correctly compressed and inserted. Pre-molded earplugs are available in different sizes (small, medium, large) and require proper sizing to ensure a snug fit within the ear canal. Custom-molded earplugs are made to fit the unique contours of an individual’s ear and typically provide a high level of comfort and protection when properly fitted. Workers should be given the opportunity to select the earplug that is most appropriate for their ear size and type. They should be offered a selection of earplugs to allow them to choose the most suitable device. If a worker has tried several types, and none are comfortable, custom earplugs should be considered.
2. Hand Hygiene: Before handling earplugs, workers should wash their hands thoroughly with soap and water, or use a hand sanitizer, to prevent introducing dirt or bacteria into the ear canal, which can lead to infections.
3. Foam Earplug Insertion: For foam earplugs, the process involves rolling the plug between the thumb and forefinger to compress the foam. It should be compressed into a small diameter and inserted deeply into the ear canal while gently pulling the outer ear upward and slightly back to straighten the ear canal and aid insertion. The earplug should then be held in place for a few seconds, allowing the foam to expand and fill the ear canal, forming a tight seal. The worker should be able to only see the outer edge of the earplug. If too much of the plug is visible, then the plug has not been inserted far enough.
4. Pre-molded Earplug Insertion: Pre-molded earplugs are typically color-coded by size. Workers must select the right size and insert the plug, again by pulling the outer ear upward and back to straighten the ear canal, gently twisting the plug until it is well seated in the ear canal. They should not be forced into the ear canal. The earplugs should be inserted into the ear until they create a tight seal, blocking the ear canal completely. It is common to need different sized earplugs for each ear. If they are not comfortable, a different size or type should be offered.
5. Custom-molded Earplug Insertion: Custom earplugs are made to fit each individual’s ears. They should be fitted into the ear canal by the person who obtained the original ear impression, and any issues with fit should be addressed by the hearing professional who made the impression. Custom plugs should be marked for right and left ears.
6. Fit Check: Regardless of the type of earplug, once inserted, workers should perform a fit check by cupping their hands over their ears. If the outside noises sound significantly reduced, the earplugs are likely inserted correctly. They should not feel any pain, but there should be a feeling of the ears being blocked. If the earplug moves easily, then it is likely too small. If it is very hard to insert, it is likely too large. If the worker can easily feel the plug when talking or moving their jaw, then it is likely that the plug is not inserted properly. Workers should be taught how to perform a fit check, and should be encouraged to carry out fit checks each time they wear HPDs.
For Earmuffs:
1. Selection of Appropriate Earmuff Type and Size: Earmuffs come in various styles (over-the-head, neckband, hard-hat-attached) and sizes. Select a model that fits comfortably over the ears without excessive pressure on the head or around the ears. The headband should be adjustable for different head sizes. Earmuffs should fully enclose both ears with the ear cushions making complete contact with the skin around the ears.
2. Positioning of Earmuffs: Place the earmuffs over the ears, ensuring that the cushions completely seal around the ears, and no hair or clothing impedes the seal. The headband should be positioned so that it is comfortable, not too tight, and not so loose that the earmuffs will fall off. For workers who wear glasses, ensure that the arms of the glasses do not break the seal. For workers with long hair, hair should be tied up to make sure the seal is complete.
3. Earmuff Seal Check: Once positioned, gently press the ear cups against the head and listen. If noises are greatly reduced, this indicates that a proper seal has been achieved. If the sounds are not reduced, readjust the earmuffs to ensure a proper seal. If the earmuffs are worn with glasses, ensure the seal is maintained.
4. Headband Adjustment: Adjust the headband for a secure, but comfortable fit. There should be even pressure around the ear cushions. The tension in the headband should be sufficient to keep the earmuffs correctly positioned. The headband should not be overly tight, but not so loose that the earmuffs will fall off.
5. Earmuff Inspection: Regularly check the cushions and headband for any damage or wear. Damaged or worn parts can affect the effectiveness of the earmuffs, and therefore require replacement. Earmuffs should be cleaned according to the manufacturer’s instructions, especially if they are shared amongst workers.
General Considerations for Both Earplugs and Earmuffs:
1. Training: Provide proper training on how to correctly fit HPDs and emphasize the importance of achieving a good fit for maximum protection. Workers should be trained about different types of earplugs, and earmuffs, and the selection and use of the correct devices for their needs. The training should also cover hygiene considerations, storage, and maintenance of HPDs.
2. Fit Testing: When possible, conduct fit testing. Fit testing confirms that the HPD being used is giving adequate protection, and may reveal any workers who have difficulty obtaining an effective seal. Fit testing should be carried out by a trained professional.
3. Comfort and Fit Issues: Workers should be encouraged to report any discomfort, irritation, or fitting issues with HPDs so that adjustments or alternatives can be found. HPDs must be comfortable to ensure workers will wear them consistently throughout their time in the noisy work areas. There are also other types of HPDs, such as custom earplugs and canal caps, which could be used for situations when neither earplugs or earmuffs are suitable.
4. Regular Checks: Workers should be encouraged to regularly check their HPDs before use to ensure that they are clean and in good working order. Any damaged HPDs should be disposed of and replaced with a new set.
By following these steps, employers can ensure that workers are properly fitted with HPDs, maximizing their effectiveness and reducing the risk of NIHL. It is important to recognize that each worker is different, and therefore the HPDs that work for one worker may not be appropriate for another. A range of HPDs should be made available to ensure that each worker can find an HPD that will provide suitable protection.