NOISE ASSESSMENT AT WORK
Hearing protection
Can foam ear plugs be reused?
Hearing test completed with used and new foam ear plugs
Hygiene and performance issues with reusing foam ear plugs
“Thank you for the report. Very comprehensive with good, easy to understand information for us to make improvements
and changes where necessary”. QHSE Manager, Hull, 2022
Sometimes we see companies setting limits on how many pairs of foam earplugs people can use in a day. Financially, we can understand where they are coming from - if they have a plug costing around 20p per pair and have say 100 staff, that will be an annual bill of about £4,800 for ear plugs assuming one pair a day. If they throw them away at lunchtime and get a new pair that bill doubles to knocking-on £10,000, a not-inconsiderable change.
However, companies cannot do that. One issue is that the performance of foam plugs gets worse with reuse (see below). Another issue is hygiene. Ear plugs do not cause ear infections but dirty hands or dirty ear plugs will.
For an ear plug to be reused each person should have somewhere clean they can put the plug when it is removed. The plug should be deigned to be reused, and it should be capable of being washed.
If a company wishes to have people reuse plugs there are a lot of styles on the market which can do this, just look for reusable silicone ones and many can come with a little case to keep them in. They cost a little more upfront but usually work out cheaper overall by fewer pairs being used.
We tested the effectiveness of reused foam plugs
We did a comparison of two pairs of earplugs. Both plugs were exactly the same brand and model and both came out of the same pack so will be the same batch.
We tested using the same ASRA audiometer, in the same location, using the same person, with one test done immediately after the other. Both sets of plugs were inserted and given time to expand.
Higher up the chart means sounds were heard at a quieter volume so the plug was reducing the sound levels less effectively. Lower down means more effective noise reduction.
The pair which had been worn three times performed significantly worse than the brand new pair. The drop in effectiveness varied from 10 to 15dB for most frequencies, and 25dB at the lowest tones.
Unless the manufacturer specifically states hearing protection is designed to be reused and clean storage is provided then they are ‘use once’ only.
