Fact Sheet - Health and safety issues related to volcanic ash
Based on historical eruptions both overseas and in New Zealand, short-term exposures to ash are not known to pose a significant health hazard. However, ash-filled air can cause short-term abrasion, inflammation and irritation injuries to eyes and to the respiratory system (nose, throat, lungs). Working in areas where ash is falling can also result in higher stress levels amongst staff.
The most commonly reported health effects within communities receiving light ash fall is broken limbs resulting from falls and slips (from ladders, roofs etc) during ash clean up. Vehicle accidents, resulting from poor visibility and slippery roads, are also common.
The following information provides guidance on how to protect workers operating in areas affected by ash fall:
Key information:
- Make dust masks or respiratory equipment available for all employees
- Safety glasses should be worn
- Contact lenses should be removed and eyeglasses worn in their place
- Keep skin protected by overalls with elasticated cuffs
- Portable washing stations should be available for hands and eyes
- Robust footwear with good grip should be worn
- Avoid driving if possible
- Clean and protect air filters in machinery
Respiratory health precautions
- Limit exposure to ash as much as possible for all employees.
- Obtain enough respiratory protective equipment to cover all employees. Dust masks should be chosen with the occupation of the people and the airborne dust concentration in mind. Heavy-duty ash removal work will require masks with greater protection
- Employees with chronic bronchitis, emphysema, asthma and cystic fibrosis should avoid any exposure to ash particles.
Eye health precautions
- Provide employees with eye protection that will exclude ash and dust (e.g. safety goggles)
- Ensure facilities are available for washing and cleaning the eye protection
- Make portable eye baths or eye wash facilities available
- Limit exposure to ash as much as possible for all employees
- Remove contact lenses
Skin health precautions
- Keep the skin protected from ash (overalls, gloves)
- Protective clothing with close-fitting, elasticated cuffs should be worn by employees required to work outside in areas of ash fall
- Portable hand washing facilities should be made available
Reducing slips, trips and falls
Ash will make surfaces slippery (especially when the ash is wet). Tripping and falling are likely to be the most common cause of injuries. Falls from ladders and roofs may be experienced if these are coated with ash (particularly wet ash)
- Keep walkways and public areas as free from ash as possible
- Provide portable lighting in areas of reduced visibility
- Ensure employees working outside have robust footwear with good grip
- Ensure appropriate safety precautions are used when working at height
Driving precautions
Reduced visibility and slippery roads will increase likelihood of vehicular and industrial accidents. Avoid driving if possible.
- If driving is necessary, drive slowly, use headlights on low beam, use ample windscreen fluid, and ensure a proper distance is maintained between vehicles
- Change oil, oil filters and air filters frequently (every 50-100 miles in heavy dust; every 500-1000 miles in light dust)
- Do not drive without an air filter. Install vent filters on outside air intakes in all vehicles that staff will be using in an ash environment, and run the heater blower on high. Blower will slightly pressurize inside of vehicle and keep dust from entering through body gaps or holes
- Clean air filters by back-flushing filter paper with compressed air (30 psi), blowing from inside (clean side) to outside (dirty side). Do not change the filters until you notice a loss of power to the engine, as a dirty filter is more effective than a clean one
Precautions for machinery
Ash has the potential to cause machinery to malfunction and perform unpredictably
- Mothball any equipment that is not needed
- Wrap or seal ash entry points on machinery (but beware of overheating)
- Clean and protect air filters
Precautions for ash removal and clean-up
- Be aware of any requirements your local authority may have for ash collection and disposal, and plan local clean up accordingly (e.g. move ash to designated pick-up points etc)
- Moisten thick ash deposits whenever possible and place in bags (to prevent its movement)
- Begin roof clean up as soon as is safely possible to avoid structural weakening
- Where possible, handle the ash in open, well-ventilated areas
- Cover loads of ash with tied down tarpaulins to stop it being spilled or blown out of skips, trucks, etc
For up to date information on the volcanic activity at Mt Tongariro, visit Civil Defence.

