How do you protect yourself from volcanic ash?

Short answer. Stay indoors with doors and windows closed during ashfall ³⁷. If you must go out, wear a well-fitting, certified N95 mask (also sold as P2, FFP2 or DS2) ¹², sealed goggles and glasses instead of contact lenses ⁶⁷. Before ash arrives, disconnect downpipes and any rainwater tank ⁶. Do not try to clear your roof while ash is still falling ⁶. Follow local authorities on roof clean-up and drinking water.

Why is volcanic ash a health problem?

Volcanic ash differs from ordinary dust: it can scratch and abrade surfaces ⁷, and its texture can range "from coarse, like sand, to fine, like cement dust" ⁷. The finer the ash, the more likely it is to reach the lungs ⁷. Fresh ash can also carry acidic particles that irritate the lungs and eyes ⁷.

Iceland's health and civil protection authorities say ash is "not immediately harmful to health," but they advise everyone to breathe in as little of it as possible ⁷. People with respiratory or cardiovascular disease, children and older people may be particularly vulnerable ⁷. Within hours or days, people can get nasal and throat irritation, coughing, red and itchy eyes, corneal scratches, conjunctivitis and skin irritation ⁷.

The problem does not end when the eruption stops. Wind can lift settled ash back into the air ("resuspension"), and this can go on for weeks or months after the eruption has ended ⁷.

What should you do when ashfall is forecast?

The New Zealand and Icelandic authorities give very similar checklists ⁶⁷:

• Go home before it starts, if you can, so you are not driving or walking during ashfall ⁶.
• Seal the house: close all windows and doors, switch off heat pumps ⁶ and, where applicable, air conditioning and heating systems ⁷, and put damp towels at door thresholds ⁶⁷. USGS also suggests taping draughty windows ².
• Use one entrance only, so less ash is tracked indoors ⁶.
• Cover electronics with plastic wrap or sheeting, and leave the covers on until the indoor area is completely free of ash ⁶⁷.
• Disconnect drainpipes/downspouts from the gutters so drains do not clog. If you collect rainwater for your water supply, disconnect the tank ⁶.
• Bring pets inside and move livestock into closed shelters, with extra feed and clean drinking water ⁶.
• Cover vehicles, machinery and spa pools. Ash can corrode metal and scratch windscreens and paintwork ⁶.
• Stock bottled drinking water and food for several days, plus any medicines you and your pets need ⁷.

Which mask actually protects against volcanic ash?

For adults, IVHHN and USGS say the most effective protection is a well-fitting, industry-certified facemask such as an N95, which is also sold as P2, FFP2 or DS2 in different parts of the world ¹². The CDC specifies a NIOSH-approved N95 respirator for time outdoors and for indoor clean-up, and treats a simple nuisance dust mask as a last resort ⁸.

How well the mask fits matters as much as what it is rated. It should seal around your face so that you cannot feel air leaking in at the edges ¹. If one model will not seal, try another. Facial hair stops a mask from sealing properly ¹. Do not wear the mask while you sleep, because it usually will not stay sealed ¹. Disposable masks may be labelled for 8 hours of use, but USGS says you can keep wearing one until it clogs or becomes hard to breathe through ².

Cloth, bandanas and handkerchiefs filter less ash than most masks and tend to fit poorly. Adding layers of cloth improves filtration, but cloth still does worse than most facemasks ¹. Wetting a mask or a piece of cloth does not improve filtration ¹².

Iceland's guide grades dust masks by filtration class ⁷:

Children: masks are usually not designed for children's faces ¹. Keep children indoors in an ash-free room where possible. If a child does wear a mask, show them how to fit it and check that it does not make breathing difficult ¹. Iceland also advises that young children should not sleep outside in a pram while there is ash in the air ⁷.

How do you protect your eyes and skin?

Wear goggles that seal around the eyes, together with long sleeves and long trousers ²⁷. Anyone who needs vision correction should wear glasses rather than contact lenses. New Zealand says ash trapped behind a lens can scratch the eye ⁶, and USGS warns that contact lenses "will result in corneal abrasion" ³. Get Ready also lists sturdy footwear and gloves for time outdoors ⁶.

Is your drinking water safe after ashfall?

Agencies agree on what to do, but they describe the risk differently:

• USGS says water "is likely to become unpalatable due to discolouration or a metallic taste before it becomes a health hazard" ⁵. For household use, it advises letting ash settle and using the clear water. If there is a lot of ash in the supply, do not run the dishwasher or washing machine ³.
• Iceland's guide says small, open water tanks are particularly vulnerable to ashfall and that "even a small amount of ash can make water unsafe for drinking," because acidity can rise ⁷.
• New Zealand warns that water restrictions are likely after ashfall and asks people to use water very sparingly, including during clean-up ⁶.

The safest approach combines these: disconnect any rainwater tank before ash arrives ⁶, drink stored bottled water ⁷, and follow notices from your water utility and health authority ⁷.

Can volcanic ash collapse a roof?

It can, but USGS calls roof collapse "a very rare impact which requires very thick ashfalls (typically >100 mm)" ⁴. Some roofs are more vulnerable and may fail at around 100 mm or less ⁴. USGS says structural damage to engineered buildings with short-span roofs is unlikely below 300 mm ⁴. Rain matters: "wetted ash is up to twice as dense as dry ash," so the load on the roof rises with it ⁴. Gutters can also clog ⁷.

Phaenyx does not give guidance on calculating or reinforcing roofs. If you are worried about a building, ask your local authority or a structural engineer. For clean-up, official advice is:

• Do not clear the roof while ash is still falling ⁶.
• Plan roof clean-up carefully, because it is hazardous. Follow your national work-at-height safety guidance ⁶. Iceland advises safety harnesses, warns that ash makes roofs slippery, and notes that the roof could collapse under the added weight of the people cleaning it ⁷.
• Lightly wet ash before sweeping and avoid dry sweeping ⁶. Do not soak it, because it hardens into a solid mass ⁷. Do not dispose of ash into drains ⁶.

What official agencies recommend

The agencies differ in two places. Iceland accepts a P1 mask, while the US and international guidance names N95 as the standard ¹⁷⁸. And USGS describes ash in water as mostly a taste problem, while Iceland warns that even a small amount can make it unsafe ⁵⁷. Where the advice differs, follow your own country's authorities.

Frequently asked questions

Does a wet cloth over my face work better than a dry one?

No. IVHHN and USGS both say that wetting cloth or a mask does not improve its ability to filter volcanic ash ¹². A well-fitting certified N95/P2 mask gives the best protection. A cloth is only a fallback when you have no mask ¹⁶.

Should I drive during ashfall?

Avoid it. Get Ready says not to drive when there is ash on the road ⁶. Iceland notes that ash cuts visibility, hides road markings and makes roads slippery, and it advises driving only if absolutely necessary, slowly and with extra distance between vehicles ⁷. Keep emergency supplies in the car, because you could be stuck in it ⁶.

How long does the ash problem last?

Wind can lift settled ash back into the air for weeks or even months after an eruption ends ⁷. Keep masks and goggles for clean-up, and you may need to change air-conditioning and heating filters often for months afterwards ⁷.

What should go in an ashfall kit?

Get Ready lists certified P2 or N95 dust masks, goggles, plastic wrap or sheeting for electronics, a broom, a shovel, a vacuum cleaner with spare bags and filters, an air duster, and heavy-duty bags for ash ⁶. Iceland adds several days of bottled water and food, medicines, a battery radio and a flashlight with spare batteries ⁷.

Prepare your kit

The official lists above share a few items worth having before ash arrives: certified masks, sealed goggles, stored water and plastic sheeting ⁶⁷⁸. Your Phaenyx plan counts them for your household. Build your Phaenyx plan.

Sources

1. International Volcanic Health Hazard Network (IVHHN) — Protection from breathing ash — https://www.ivhhn.org/ash-protection (accessed 2026-10-20)
2. U.S. Geological Survey, Volcano Hazards Program — Impacts & Mitigation: Protecting Against Ash — https://volcanoes.usgs.gov/volcanic_ash/protecting_against_ash.html (accessed 2026-10-20)
3. U.S. Geological Survey, Volcano Hazards Program — Impacts & Mitigation: What to do during ashfall — https://volcanoes.usgs.gov/volcanic_ash/what_to_do_during_ashfall.html (accessed 2026-10-20)
4. U.S. Geological Survey, Volcano Hazards Program — Impacts & Mitigation: Roof Loading — https://volcanoes.usgs.gov/volcanic_ash/roof_loading.html (accessed 2026-10-20)
5. U.S. Geological Survey, Volcano Hazards Program — Impacts & Mitigation: Water Supply — https://volcanoes.usgs.gov/volcanic_ash/water_supply.html (accessed 2026-10-20)
6. Get Ready / National Emergency Management Agency, New Zealand — Volcanic activity (large-print edition) — https://getready.govt.nz/assets/Uploads/documents/alternate-formats/large-print/docx/11-volcanic-activity-lp-en-aug26.docx (accessed 2026-10-20)
7. Chief Epidemiologist and Department of Civil Protection (Almannavarnir), Iceland — Volcanic ash: health hazards. A guide for the public, 3rd edition, November 2023 — https://www.mast.is/static/files/baeklingar/volcanic-ash-health-hazards.-3rd-edition.-20.11.2023.pdf (accessed 2026-10-20)
8. U.S. Centers for Disease Control and Prevention (CDC) — Preparing for a Volcanic Eruption — https://www.cdc.gov/volcanoes/safety/index.html (accessed 2026-10-20)