Fire & Rescue NSW

Navigation

Smoke alarm questions and answers

Sunday, 1 May 2016 marks the 10-year anniversary of the introduction of NSW legislation to ensure all homes have at least one working smoke alarm per floor. As smoke alarms can be affected by dust, insects, humidity and age, they need to be replaced at least every 10 years. Importantly, technology has moved on over the past 10 years.

Fire & Rescue NSW is encouraging NSW residents to ReAlarm their homes during May, replacing old, outdated smoke alarms that rely on regular 9V batteries with newer photoelectric smoke alarms that rely on 10-year lithium batteries. Photoelectric smoke alarms have fewer false activations and are more effective at detecting the types of fires that are most likely to result in a home fire death - smouldering fires.

When and why was the smoke alarm legislation introduced?

On 1 May 2006, the NSW Government introduced new legislation following a series of fatal house fires.

This legislation mandated that all residential dwellings in NSW must have at least one working smoke alarm installed on each level of the home. This includes; owner occupied and rental properties, relocatable homes, caravans and campervans or any other residential building where people sleep. Nationally, smoke alarms must comply with Australian Standard 3786 (AS3786), which should be clearly marked on the packaging.

What’s the difference between photoelectric and ionisation alarms?

Fire & Rescue NSW strongly recommends photoelectric smoke alarms. The preference is for hard-wired photoelectric smoke alarms that are interconnected with other alarms within the home. Hard-wired interconnected smoke alarms must be installed by a certified electrician. However photoelectric smoke alarms with 10-year lithium batteries are also very effective.

Photoelectric alarms are more advanced and are widely regarded as being superior to ionisation alarms in most circumstances. They can respond faster than other alarms to most fire types and are less likely to cause false alarms. Photoelectric alarms are particularly effective at detecting smouldering fires, which provides the earliest possible warning of a small developing fire.

Ionisation smoke alarms ‘feel’ the smoke. Technically, ionisation smoke alarms contain a small amount of radioactive material between two electrically charged plates, which ionises the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the current and activating the alarm.

Photoelectric alarms ‘see’ the smoke particles. Technically, photoelectric alarms use a light source and a light sensor. When the smoke enters the alarm’s sensing chamber the light sensor detects a change in the light pattern, triggering the alarm.

Photoelectric smoke alarms:      

  • Rely on newer technology
  • Result in fewer annoying false alarms
  • Picks up more types of fires

Ionisation smoke alarms

  • Rely on older technology
  • Result in more annoying false alarms
  • Are less reliable

Why do we recommend photoelectric smoke alarms? (why does my smoke alarm go off all the time like when cooking dinner)

Studies have shown that photoelectric alarms are more effective at detecting the types of fires that are most likely to result in a home fire death: smouldering fires. Photoelectric smoke alarms are also less likely than ionisation alarms to go off when people are cooking, or using the shower, which prompts many people to disable them.

What do people need to look for on packaging when buying a photoelectric smoke alarm?

FRNSW recommends people look for a smoke alarm that is clearly marked ‘photoelectric’ on the package. Some smoke alarms indicate which area of the home they’re designed for. You can be sure you have a photoelectric and not ionisation as ionisation alarms have a yellow radioactive sticker.

FRNSW’s preference is for residents to have hard-wired photoelectric smoke alarms that are interconnected throughout the home. But, as a minimum, FRNSW recommends photoelectric alarms that rely on 10-year lithium batteries rather than normal 9V batteries which need to be replaced at least once a year. Ten-year lithium batteries last as long as the smoke alarm so you don’t need to worry about replacing them every year – you simply replace the entire smoke alarm unit once every 10 years.

How do people know what alarm they have and how old it is?

If you are unsure of how old your alarm is and whether or not it’s photoelectric or ionisation, the best option would be to replace your smoke alarm.

Ionisation alarms should have a yellow sticker indicating radioactive material. Photoelectric alarms do not have these stickers. There should be a date of manufacture somewhere on the back of the alarm but it is not legislated as to where it would be.

To assist in identifying the age of smoke alarms the AS3786 standard requires a serial number or batch number, e.g. 2406 may mean that the product was manufactured in the 24th week of 2006. Some manufacturers place the date of manufacture on the smoke alarm and some now place the expiry date on the smoke alarm. The batch numbers or dates are usually on the base of the smoke alarm near the battery compartment.

If you have a newer ionisation alarm, you can leave it up but FRNSW recommends adding a photoelectric alarm.

Where should smoke alarms be positioned?

There are minimum requirements needed to meet the Building Legislation Amendment (Smoke Alarms) Act 2005, however Fire & Rescue NSW recommends you aim for a higher level of protection with alarms installed in bedrooms, hallways and lounge rooms.

Under the Act, different types of premises require smoke alarms to be installed in various locations. For residential dwellings, a smoke alarm should be installed on each level of the home. The alarm should be on the ceiling between the kitchen and sleeping areas, close enough to be heard from the bedrooms.

A common mistake is that smoke alarms are installed too close to the kitchen or bathroom. FRNSW would recommend positioning alarms closer to bedrooms and access routes in and out of the home.

How should residents maintain their smoke alarms (testing / batteries etc)?

Fire & Rescue NSW recommends the following maintenance:

Every month: Smoke alarms should be tested (by pressing the test button) to ensure the battery and the alarm work.

Every six months: Smoke alarms should be cleaned with a vacuum cleaner. This will remove any dust or particles that could prevent the smoke alarm from working properly.

Once a year: If your smoke alarm has a regular 9V battery (lead or alkaline), you should replace the battery. A good way to remember is to change it is whenever you change the clocks for the end of Daylight Saving. If your smoke alarm uses a lithium battery, it is inbuilt into the alarm and cannot be replaced. The entire unit will need replacing every 10 years.

Every 10 years: Replace your smoke alarm. Smoke alarms do not last forever and the sensitivity in all smoke alarms will reduce over time. All types of smoke alarms should be removed, replaced and disposed of at least every 10 years.

Why, on the 10th anniversary of the legislation, do people need to replace their alarms?

According to Fire & Rescue NSW (FRNSW) data, 56 per cent of fatal home fires between 2000 and 2014 occurred in homes where no smoke alarms were present. A working smoke alarm provides a critical early warning giving you and your family time to escape. It can take three minutes for a fire to take hold and takes only two quick breaths of thick, black smoke to render someone unconscious.

Smoke alarms need to be replaced at least every 10 years, so it is important, on the 10th anniversary, that NSW residents ReAlarm their homes by replacing their outdated smoke alarms.

It’s also important to recognise that a lot has changed over the past 10 years. Technology has come a long way with newer photoelectric alarms that result in fewer false alarms and are more likely to detect the most deadly kind of home fires – smouldering fires.

We also know that homes today are more likely to be filled with quick-burning, modern furnishings. This means fires can progress to a fatal ‘flashover’ (become fully involved by fire) in as little as three minutes, compared with the 1970s, when it took up to 20 minutes. Newer technology in photoelectric smoke alarms is more sensitive to the dense smoke given off by foam-filled furnishings or overheated PVC wiring.

We also know that older ionisation alarms can be affected by cooking and steam. Annoying false alarms lead residents to ‘deactivate’ their working smoke alarm – a potentially deadly move. This May, on the 10th anniversary of the introduction of smoke alarm legislation in NSW, ReAlarm your home by replacing your smoke alarms.

What if I’m hard of hearing or I can’t change my smoke alarm myself?

There are a number of different types of smoke alarms available: photoelectric, ionisation, carbon monoxide (note: carbon monoxide alarms are not smoke alarms and do not satisfy the legislation, they may only be used in addition to smoke alarms for increased warning), alarms for the deaf and hearing impaired, alarms with emergency lights, and special models for kitchens and relocatable homes. All of these smoke alarms differ in how they detect smoke and/or alert people. FRNSW runs the Smoke Alarm Battery Replacement (SABRE) program to help at-risk communities, especially the elderly, install and maintain their smoke alarms. For more information about SABRE, click here.

FRNSW also works with the Deaf Society of NSW on the Smoke Alarm Subsidy Scheme for the deaf and hearing impaired. Through the society, special smoke alarms are subsidised for those who are deaf, deafblind or hard of hearing. For more information about these smoke alarms click here.

If I get a new smoke alarm do I still need to change my battery every year?

If you replace your existing smoke alarm with a lithium-powered 10-year photoelectric smoke alarm then you don’t need to change the battery – you simply replace the entire smoke alarm unit once every 10 years.

How do I dispose of old ionisation smoke alarms?

You can safely throw out up to 10 ionisation smoke alarms in your household waste garbage bin. If you need to dispose of more than 10 smoke alarms, see the statement below.

FRNSW Statement to Local Government Councils on the Safe Disposal of Ionisation Smoke Alarms, as per NSW EPA Guidance

FRNSW has been informed the following by the NSW EPA Radiation Team Manager, Mr. Len Potapof:

Up to 10 ionisation smoke alarms can be disposed of in household waste

If there are more than 10 ionisation smoke alarms to be disposed of at one time they should be taken to a local Community Recycling Centre

Consideration must be given to cumulative effect such that if 10 smoke alarms are to be disposed of daily in the same household waste, it would be preferable to dispose of them at a local Community Recycling Centre

Community Recycling Centres (CRCs) have been established in partnership between local governments and the EPA to dispose of bulk waste materials, including ionisation smoke alarms.

The EPA website offers advice on smoke alarms and their appropriate disposal, with reference that small numbers can be taken to CRCs, and to contact the EPA with questions about large numbers. The manager of the Radiation Team advised FRNSW by phone that larger numbers can be taken to CRCs. Public advice is available here

Information surrounding CRCs is available here

A list of CRCs is available here