Health risks from smoke and ash - HE2909

Public Health Information Sheet

Smoke can be a health hazard. Fine particles in soot and ash can irritate lungs and skin. Soot and ash can settle on surfaces around your home and garden for several days after the fire has been extinguished. Fire retardants and foam from firefighting may also be present.

Smoke and ash inhalation can be dangerous

Smoke may irritate your eyes, nose, throat and airways. Symptoms can include runny or sore eyes, dry or sore throat, sore nose, cough, tightness of chest or difficulty breathing. Most people’s symptoms disappear soon after their smoke exposure ends, causing no long-term health problems.

If you are in an area where you can see or smell smoke or have received an emergency alert, you should:

• Follow the advice of emergency services and leave the area if this is required.
• If you are safe to stay in the area, remain indoors and shut your windows and doors.
• Turn off your air conditioning or switch to ‘recirculate’.
• Keep pets inside with clean water, food and bedding.
• Some people are more at risk from smoke and ash inhalation such as
  • Elderly or pregnant people
  • Babies and young children
  • Those with heart or lung conditions like asthma or heart disease.

These people should stay indoors until the smoke has cleared. They should avoid any clean-up of ash and soot around the home if possible.

Breathing in fine particles of ash or soot can worsen pre-existing medical conditions such as asthma and heart disease. Please continue to take any medications for these conditions.

If you experience shortness of breath, wheezing, asthma or chest pain please see your doctor immediately or call 111. For health advice you can also contact Healthline for free anytime on 0800 611 116 

Ash and soot can contaminate water and food

If your drinking water comes from tanks

• If you are not on Council water supply, you will need to check your roof and rainwater storage tanks for ash, debris, fire retardants or foam.
• You should disconnect the downpipe to the water tanks if you see any evidence or there is risk of ash, debris, retardants or foam, or there is a risk of any of these. They will contaminate your water supply. For people needing assistance, contact whānau, neighbours, volunteers or your local Civil Defence.
• If you find ash in your water tank or the water has an unusual taste, odour or appearance (possibly a sign of retardants or foam) don’t use the water for drinking, food preparation, cleaning teeth, washing or for pets.
• Disinfecting or boiling the water will not remove ash, retardants or foam.
• Water runoff after fires might contaminate streams, rivers, lakes and groundwater supplies. If your water comes from one of these sources, arrange for it to be tested.
• Use bottled water or saved water as an alternative safe supply.
• Do not reconnect the downpipe until a good flush of rain has cleaned the roof or it has been hosed down.
• Contaminated water can be used to flush toilets and water gardens.

Food Safety

• Wash fruit and vegetables from your garden with safe drinking water before cooking or eating raw. Do not use rainwater from a tank.

Cleaning up

If your home has been affected by smoke, take steps to clean up ash and soot safely.

• Wear a N95 or P2 mask if you have one (from a hardware or health and safety shop), otherwise a surgical mask.
• Wear gloves, a long-sleeved shirt and long pants to avoid skin contact.
• Wash your hands regularly, particularly after clean-up and before eating.
• Children should NOT be involved in any clean up.
• If your home has been heavily contaminated with ash, soot or smoke, consider using a professional cleaner. Check your insurance policy covers smoke damage and clean-up by contacting your insurance company.

Cleaning up ash inside your home

• Wash hard surfaces, toys, food preparation areas, pet food and water bowls and any cooking utensils left out, using hot water and detergent.
• Wipe any visible soot or dust (e.g. on windowsills) using a damp cloth or mop with detergent.
• Vacuum clean carpets and upholstery, preferably using a vacuum cleaner with a HEPA filter.
• Clean air conditioning unit filters or ventilation systems or ask your property manager to do this.  
• Clothing exposed to smoke in the house or on the washing line should be washed.

Cleaning up ash outside your home

• Hose down ash and debris from your roof, exterior walls and outdoor surfaces.
• Remove large pieces of debris with gloves, ensuring the debris is cool before placing it in the bin.
• Clean filters and covers of outdoor pools.

Fire retardants and foams

Firefighting retardants and foams may be used to fight the fire. These do not present a significant risk to health and will break down with rain. They may leave a pink or soapy substance around the area of the fire.

For more information

• Restoring your property | Fire and Emergency New Zealand – Fire and Emergency NZ
• How to make water safe to drink under a boil water notice | Taumata Arowai – Taumata Arowai