• Materials and Construction – Any materials used to make the product that will come into contact with the skin must be non-staining and not likely to cause allergic reaction, skin irritation, or other adverse effects on health. The ear defenders must be free from sharp edges to be considered safe for use, and cleaning and disinfection methods specified should not cause damage or impairment to the hearing protection.
• Size and Adjustability – This is tested to ensure that ear defenders are suitable for the range of head sizes designated by the manufacturer. With EN 352-1 compliant products you should expect an adequate fit.
• Cup Rotation – Hearing protectors are measured to assess whether the rotation of the cups is sufficient. There must be enough rotation for wearers to adjust the device to achieve the best fit.
• Headband Force – There should be no excessive force on the wearer’s head.
• Cushion Pressure – There should be no excessive pressure on the wearer’s head.
• Resistance to damage when dropped – For this test, the ear protection product is dropped from a specified height onto a solid steel plate.
• Change in Headband Force – After the tests above have been completed, headbands are subjected to flexing for 1,000 cycles, before being conditioned in a water bath at 50^oC for 24 hours. Once complete the headband force is measured a second time. A maximum deviation between the 2 measurements determines whether is passes.
• Resistance to Leakage – This is specifically for ear muffs with fluid-filled cushions. A vertical load of 28±1 newtons is applied to the cushion for 15 minutes and any leakage caused will constitute a test failure.
• Ignitability – A steel rod heated to around 650^oC is applied to the hearing protection device. If any part ignites or continues to glow after the removal of the rod then the device will fail the ignition test.
• Minimum Attenuation – The minimum attenuation value must be recorded for EN 352-1 compliant ear defenders. This is the lowest sound pressure level perceivable by the ear f 16 human test subjects with and without the hearing protection worn. It is then possible to calculate the performance of the model from these values.

Ear plugs are tested for many of the properties outlined in EN 352-1, including;

• Sizing and adjustability
• Materials and construction
• Resistance to damage when dropped
• Ignitability
• Minimum attenuation

There are some small differences – Custom moulded ear plugs are not tested for sizing and adjustability, and with reusable ear plugs, the method of cleaning and disinfection specified is assessed to ensure it causes no significant alteration to the acoustic performance or to the material and construction properties.

EN 352-3 products are test to all of the properties in EN 352-1, as well as specific testing methods for helmet mounted ear defenders.