iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Protect yourself by treating ash and vog as different hazards. Volcanic ash is abrasive particulate matter: stay indoors during ashfall, close openings, and use a NIOSH-approved N95 (or equivalent) for unavoidable outdoor exposure and cleanup. Vog contains volcanic gases, including sulfur dioxide (SO₂), that an N95, cloth mask, or ordinary particle filter does not remove. During vog, follow local air-quality alerts, reduce outdoor activity, keep doors and windows closed when advised, and use indoor recirculation.
Conditions can change quickly. Check your local emergency-management, public-health, volcano-observatory, and air-quality alerts before deciding whether to shelter, leave, drive, clean, or use tap or catchment water.
First decide whether you are dealing with ash, vog, or both
The protective action depends on what is in the air. Ash is made of tiny fragments of volcanic rock and glass. It can irritate the eyes, nose, throat, and lungs, contaminate surfaces and water, reduce visibility, damage machinery, and become heavy when it accumulates on a roof. Vog (volcanic smog) is air pollution produced when volcanic gases react with moisture and sunlight. Sulfur dioxide (SO₂) is a key concern, along with fine particles and other gases that vary by eruption and weather.
| Hazard | Main concern | What helps | What does not solve it |
|---|---|---|---|
| Volcanic ash | Breathing abrasive particles; eye and skin irritation; contamination; roof and equipment loading | Indoor shelter, closed openings, a properly fitted NIOSH-approved N95 or equivalent particulate respirator, goggles, damp cleanup, and clean filters | A loose cloth covering or nuisance dust mask offers much less protection; a particle respirator does not remove volcanic gases |
| Vog and SO₂ | Gas irritation and respiratory aggravation, especially for sensitive people | Reduce outdoor exposure, stay indoors when advised, close windows and doors, set air conditioning to recirculate, keep medicines accessible, and follow current local alerts | An N95, cloth mask, HEPA filter, or ordinary particle air cleaner should not be presented as SO₂ protection |
| Ash-contaminated water | Unsafe or untested drinking water and blocked or damaged catchment equipment | Use another drinking-water source until testing and local advice clear the supply; disconnect rainwater downpipes during ashfall | Do not assume visible settling or household filtration makes contaminated water safe |
The safest way to eliminate significant exposure to volcanic particulates, vog, or gases such as SO₂ is to leave the affected area when authorities advise that option. Hawaiʻi Department of Health guidance uses that wording for significant exposure; evacuation decisions must follow the instructions for your location.
#1 Best Overall
- NIOSH Approved : (NIOSH Approval Number: TC-84A-9276) - NIOSH Approved N95 respirator mask certified for at least 95% filtration efficiency against particulate aerosols free of oil.
- Credible Manufacturer : Manufactured by Shanghai Yunqing Industrial Co., Ltd., a NIOSH approved manufacturer of N95 respirator mask. The mask is listed on the NIOSH website as an approved N95 mask.
- Standard Head Loops : This is a NIOSH approved N95 mask that straps must go behind head instead of the ears to offer better protection. The straps are firmly attached and made of very comfortable cotton materials, more comfortable to wear for long periods of time.
- New Upgraded Material : The active filter layer of these N95 masks is composed of dual ultra-high grade electrostatically charged meltblown polypropylene. Our N95 respirators far exceeds NIOSH filtration requirements, filters at least 95% non-oil based airborne particles with less than 60pa breathing resistance. Skin-friendly non-woven inner layer gives you the most comfortable wearing experience.
- Adjustable Nose Clip : Moldable nose clip with anti-fog cushioning foam provides better seal and reduced fog on eyewear. With plastic covered metal nose clip, it is not easily broken and can be used many times.
What to do when ash is falling
1. Check official alerts before changing your plan
Read the latest instructions from local emergency management and public-health agencies. An eruption can produce changing wind direction, ash concentration, road closures, evacuation orders, and advice about water or shelter. Do not substitute a general internet forecast for a local alert. If an order says to evacuate, leave by the designated route rather than trying to make an indoor shelter last indefinitely.
2. Shelter indoors and seal the obvious openings
- Go inside when possible and keep windows and exterior doors closed.
- Close fireplace and woodstove dampers so ash cannot enter through the flue.
- Shut doors to garages, porches, and other semi-open areas where ash is accumulating.
- Turn off fans, heating, and air-conditioning equipment that draws outside air, unless local emergency guidance or a life-safety need requires another setting.
- Close outdoor-air dampers and use a recirculation setting on equipment that supports it.
Follow the equipment manual and local emergency guidance: disabling ventilation can create a competing hazard in some homes, and heat, smoke, carbon monoxide, or other emergencies take priority. Replace disposable furnace filters frequently during ash events, or clean permanent filters as the manufacturer specifies. A loaded filter can restrict airflow and may allow more particles to bypass or enter through leaks.
3. Do not assume indoor shelter is safe forever in heavy ashfall
Ash is dense and can become much heavier when wet. Accumulation can overload roofs, damage gutters, block vents and air intakes, and make a building difficult to ventilate. Watch local instructions about roof loading and structural safety. If authorities identify a roof or air-intake hazard, follow their direction to leave or obtain professional assistance. Do not climb onto a roof simply to inspect it during an active ashfall.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Repair Windows errors before they cause bigger problems3Scan for outdated or missing drivers - takes under a minute4. Protect eyes and skin
Wear long sleeves, long trousers, gloves, and sturdy footwear when outside or cleaning. Goggles that seal reasonably around the eyes provide better protection than ordinary glasses against blowing ash. Avoid rubbing ash-covered eyes; rinse with clean water and seek medical advice if pain, light sensitivity, or vision changes continue.
Rank #2
- NIOSH APPROVED: For at least 95 percent filtration efficiency against certain non-oil based particles
- COMPATIBLE: With a variety of protective eyewear and hearing protection
- ADJUSTABLE NOSECLIP: Reduces potential for eyewear fogging and helps provide a custom and secure seal
- TWO-STRAP DESIGN: With welded dual point attachement that helps provide a secure fit
- APPLICATIONS: Gringing, sanding, sweeping, bagging, and other dusty operations. Metalworking, chemical processing, construction, and metal processing
5. Avoid driving in dense ash
Heavy ash can cut visibility, become airborne behind vehicles, clog filters, damage engines, and cause a vehicle to stall. Avoid driving unless it is necessary or authorities direct you to travel. If you must drive, keep windows closed, turn off outside-air ventilation, use headlights as required by local law, and drive slowly. Do not run an air conditioner in a mode that pulls outside air into the cabin.
How to choose and use a respirator
Use a certified particulate respirator for ash
CDC advises wearing a NIOSH-approved N95 respirator (also called an air-purifying respirator) outdoors or while cleaning ash that has entered a home. An equivalent particulate respirator may be appropriate where local authorities recognize that certification. Check the package for the approval marking and model information; do not assume that a mask described only as “dust,” “comfort,” or “nuisance” protection meets the same standard.
A respirator works only when it seals to the face. Follow the manufacturer’s donning and user-seal-check instructions every time. Facial hair, glasses, movement, sweat, and an incorrect size can create leaks. Replace a disposable respirator when it is dirty, damaged, difficult to breathe through, or no longer seals. Do not share a used respirator.
Know the limits
N95-type respirators filter particles, not toxic gases or vapors. They do not protect against SO₂ in vog. A cloth mask, scarf, surgical mask, or nuisance dust mask offers less reliable particulate protection and should not be described as gas protection. Hawaiʻi Department of Health guidance specifically warns that particulate masks do not protect against SO₂ or other volcanic gases.
Rank #3
- 20-pack NIOSH Approved N95 Respirator Mask - (NIOSH Approval Number: TC-84A-9315) - N95 mask certified for protection against 95% of non-oil based particles 0.3microns or larger. Size Medium/Large. Elastic bands go over the head, not over the ears.
- MADE IN USA – Manufactured by BNX Converting LLC in Houston TX, a NIOSH/CDC Approved and FDA Registered (Registration # 3017489417) manufacturer of N95 mask respirators.
- Superior Protection & Breathability - BNX’s 5-layer filtration technology provides maximum protection, comfort and breathability. The active filter layer of these N95 masks is composed of ultra-high grade electrostatically charged meltblown polypropylene. Extremely breathable up to 50%+ more breathable than NIOSH minimum requirement.
- Latex Free Enhanced Comfort and Secure Fit - Features latex free and amazingly soft and durable headband straps as well as an adjustable metal nose piece to ensure a tight yet comfortable seal. Please follow all recommended fitting instructions and guidelines to ensure proper fit and protective seal. Flat fold design allows for convenient storage prior to use. Improved 3D design provides room for your mouth to move when you speak and greater compatibility with and reduced fog on eyewear.
- BNX Quality Promise & Applications - BNX is committed to delivering the highest quality American made safety products using the latest automated manufacturing processes and technology and the strictest quality standards. Our N95 respirator masks are ideal for use by industries such as: Commercial Buildings, Construction, Food Processing & Safety, Retail, Manufacturing, Infrastructure, Education, Oil & Gas, Transportation, and mor
People who should avoid ash cleanup
Anyone with asthma, chronic obstructive pulmonary disease (COPD), emphysema, or another lung condition should avoid cleanup when possible. If cleanup cannot be avoided, ask a medical professional or local public-health agency for individualized advice before starting. Children, older adults, pregnant people, and anyone with heart or lung disease may also need a more conservative exposure plan based on local health instructions.
How to clean ash without putting it back in the air
Prepare before disturbing settled ash
- Check that local authorities have declared cleanup safe and that no evacuation or roof warning overrides the task.
- Wear a properly fitted NIOSH-approved N95 or equivalent particulate respirator, goggles, gloves, long clothing, and sturdy shoes or boots.
- Keep people with respiratory conditions, children, and pets away from the work area.
- Turn off equipment that could draw ash through the home, and protect clean indoor areas from contaminated clothing and tools.
Dampen, collect, and contain
- Lightly dampen settled ash before sweeping or collecting it. Do not saturate a roof or structure if added weight could create a hazard.
- Use methods that minimize dust, such as damp wiping and careful collection. Avoid dry sweeping, compressed air, and leaf blowers, which can resuspend ash.
- Bag or otherwise contain collected ash according to local waste instructions. Do not wash large quantities into drains, gutters, septic systems, or stormwater channels.
- Remove outer clothing and footwear before entering clean areas, and wash hands and exposed skin after the task.
- Clean or replace furnace and ventilation filters as specified for the equipment and the local event.
Be especially cautious on roofs
Roof ash is heavy and slippery. A fall risk is added to the loading risk, and wetting a large deposit can increase its weight. Avoid roof cleanup unless it is necessary, local officials say it is appropriate, and you have the training, fall protection, and structural information to do it safely. A hard hat is appropriate for roof work, but it does not make an unsafe roof safe. Use a qualified professional when the deposit, slope, height, or building condition exceeds your capability.
How to reduce vog exposure indoors
Change behavior when alerts show elevated vog
- Reduce outdoor exercise, errands, and other nonessential activity, particularly during periods when local monitoring reports poor air quality.
- Stay indoors and close windows and doors when public-health guidance recommends it.
- Set air conditioners and vehicle climate systems to recirculate instead of drawing outdoor air.
- Keep prescribed respiratory medicines and a written action plan accessible. Do not delay prescribed treatment while trying a household air-cleaning device.
- Contact a medical provider if symptoms develop or worsen. Seek urgent help for severe breathing difficulty, chest pain, confusion, blue lips, or other emergency symptoms.
Symptoms can include irritation of the eyes, nose, throat, and airways, coughing, wheezing, shortness of breath, chest tightness, headache, or worsening of an existing respiratory condition. The response to a given vog episode depends on concentration, wind, time outdoors, and personal health. Use the current local health alert rather than a fixed “safe” duration from another region.
Recommended Free Tools
What an air cleaner can and cannot do
A portable air cleaner designed for particles can reduce indoor particulate matter when it is correctly sized, operated, and maintained. It does not automatically remove SO₂ or other volcanic gases. A HEPA filter is a particle filter; do not claim that it removes volcanic gas. Gas removal requires product-specific evidence, an appropriate sorbent or other technology, adequate airflow, and maintenance under the actual conditions. If a manufacturer does not provide credible data for SO₂, treat the device as particle-only.
Rank #4
- NIOSH-APPROVED N95 for at least 95 percent filtration efficiency against certain non-oil-based particles and aerosols
- 3M COOL FLOW EXHALATION VALVE helps direct exhaled air downward and allows for easy breathing
- UP TO 50% EASIER BREATHING. Compared to non-valved 3M 8200 Testing
- ADVANCED FILTER MEDIA for easy breathing
- ADJUSTABLE M-NOSECLIP helps provide a custom and secure seal
Close doors and windows first: an air cleaner cannot compensate for a continuous supply of polluted outdoor air. Keep the unit’s intake and exhaust unobstructed, replace filters on schedule, and avoid ozone-generating devices in occupied spaces. No household air cleaner makes an evacuation order unnecessary.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Protect drinking water and rainwater catchment
Visible ash in a water supply
If ash is in drinking water, use another source, such as bottled water, until the supply has been tested and the water provider or public-health authority says it is safe. This applies to drinking, cooking, making infant formula, brushing teeth, and preparing ice. Do not rely on appearance, taste, boiling, or a standard household filter as proof that ash-affected water is safe.
Rainwater tanks and roof catchment
- Disconnect or divert downpipes feeding rainwater tanks while ash is falling, following local instructions for the system.
- Prevent fresh ash from entering tanks and keep tank openings covered where the system design allows.
- Ask the local water authority or public-health agency how to inspect, clean, sample, and reconnect the system.
- Do not use untreated catchment water for drinking or food preparation until testing and local guidance clear it.
Hawaiʻi Department of Health’s vog guidance adds a location-specific concern: acidic catchment water in vog-prone areas can leach metals such as lead, copper, and zinc from roofing and plumbing materials. That department generally does not recommend catchment water for drinking or food preparation for health and safety reasons. This is Hawaiʻi-specific advice, not a universal rule for every jurisdiction; follow your own water supplier and public-health authority.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Municipal water is a different question
A regulated municipal supply may have different protections and testing from a private roof-catchment system. Follow boil-water notices, “do not drink” notices, and utility updates exactly. If ash has entered household plumbing or a private well, ask the responsible authority which tests are needed before resuming use.
Best Value
- NIOSH-APPROVED N95 for at least 95 percent filtration efficiency against certain non-oil-based particles and aerosols
- USE FOR: Sanding, drywall cutting, sweeping, sawing, woodworking, fiberglass insulating, yard work, grinding and dusting
- 3M ADVANCED ELECTROSTATIC MEDIA enhances the capture of airborne particles and allows for easy breathing
- 3M COOL FLOW VALVE helps release warm, exhaled breath from inside the respirator
- UP TO 50% EASIER BREATHING Compared to 3M 8200
Household equipment and preparedness checklist
Prepare these items before an eruption if your area is at risk:
- NIOSH-approved N95 or equivalent particulate respirators in several sizes, stored sealed and dry.
- Goggles, disposable or washable gloves, long-sleeved clothing, sturdy footwear, and cleaning supplies that support damp methods.
- Replacement furnace or HVAC filters that match the equipment, plus the manufacturer’s filter-change instructions.
- Clean drinking water or a way to obtain it if ash affects the supply.
- Prescribed medicines, a written respiratory action plan, and reliable ways to receive local alerts.
- Plastic bags or covered containers for contaminated clothing and collected ash, used according to local disposal rules.
Before an event, identify which doors and windows seal well, learn how to close outside-air dampers, find the HVAC recirculation control, and know where the main fans and air-conditioning controls are. Confirm whether your roof, attic vents, and rainwater system need professional inspection after ashfall.
When to leave, call for help, or seek medical care
Leave when authorities direct you
Evacuate for an official order, an unsafe roof or building, blocked ventilation or air intakes, advancing lava or fire, or any condition local responders identify as life-threatening. Take medicines, identification, essential water, and respiratory protection if time permits; do not remain to finish cleaning or collect belongings.
Get medical advice for persistent or worsening symptoms
Move to cleaner air and contact a healthcare professional for ongoing cough, wheezing, breathing difficulty, chest tightness, unusual fatigue, or symptoms that are worsening or interfering with normal activity. People with asthma or other chronic lung disease should follow their personal action plan and seek help sooner if relief medicine is not working as directed. Emergency symptoms require emergency services, not a stronger mask or air cleaner.
Quick Recap
Common mistakes to avoid
- Using an N95 as a gas mask: it filters particles, not SO₂ or other volcanic gases.
- Keeping outside-air ventilation running: fans, air conditioners, and open dampers can draw ash or vog indoors.
- Dry sweeping ash: it can create a new airborne exposure; dampen settled ash first.
- Climbing onto a loaded roof: ash is heavy and slippery, and a respirator does not prevent a fall or structural collapse.
- Driving normally in heavy ash: visibility loss and engine or filter damage can strand you.
- Assuming a HEPA purifier removes SO₂: particle filtration and gas removal are different functions.
- Drinking from an affected catchment tank: visible ash and vog-related acidity require local testing and water-health advice.
- Ignoring updated alerts: wind, eruption intensity, and safe routes can change within hours.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
