Hawai‘i Emergency Management Agency

The following information will help you decide on which type of respiratory protection to use, but other factors, such as the cost and availability of the protective products, may also need to be taken into account.

When you wear respiratory protection, the effectiveness depends particularly on two factors:

1) how effective the mask or material is at filtering particles (stopping the ash from passing through the material);

2) the fit of the mask or material to the face (preventing particles from entering around the edges).

• The most effective respiratory protection for adults is to wear a well-fitting, industry-certified facemask such as an N95 mask (also called P2, FFP2 or DS2 in different parts of the world). The certification will be printed on the mask. Such masks are usually disposable.
  • These are highly-efficient at filtering ash and are also usually designed to fit adult faces well, but may be too big for children.
  • Due to their tight fit, they may feel uncomfortable.
  • Using highly-effective masks can make breathing harder; if you have existing respiratory or cardiovascular disease, talk to a health professional about whether such masks are suitable for you.
  • These masks come in many different shapes and sizes. Some fold out into a mask shape and some have a ready-made cup-shape. Some have a valve on the front to improve comfort by letting hot, humid air out. All of these masks will be highly-effective at filtering ash, if worn properly.
• Some non-certified facemasks state that they are designed to filter ‘PM_2.5’ (small particles less than 2.5 micrometres in diameter), which is likely to be the most harmful fraction of the ash.
  • These are probably highly-efficient at filtering ash but are often not designed to fit well to the face and so may not be very effective.
• A standard, pleated surgical mask will be good at filtering ash as long as it fits well to the face. If it does not, it will provide less protection than an industry-certified facemask.
• Simple healthcare masks (rectangular, non-pleated) do not filter ash well and also do not have ways to make a good seal to the face.
• Hard-cup (also called nuisance-dust), ‘fashion’ and scooter masks are less effective at filtering ash compared to industry-certified and surgical masks, and may not fit well to the face.
• Cloth materials (e.g., bandanas, t-shirts, veils, handkerchiefs) worn over the nose and mouth are less effective at filtering ash than most masks, so will offer less protection and they also tend not to fit well.
  • Increasing the number of layers of cloth improves the ability to filter ash but will still be less effective at filtering ash than most facemasks.
• Wetting materials does not improve the ability of masks or cloth to filter volcanic ash.

For more  information, visit www.ivhhn.org/ash-protection