Smoke alarms aren't a fit-and-forget device. They have a working life, not an indefinite one.
Why alarms age out
Dust and residue build-up inside the sensing chamber over the years is the commonly cited reason smoke alarms lose sensitivity with age, even when a unit still passes a basic test-button check. This is why every My Safe Home check records the age of every alarm on the property, not just whether it beeps.
The standard
Smoke alarms sold and installed in Australia must comply with AS 3786, the Australian Standard specifying requirements, test methods and performance criteria for smoke alarms. The current edition is AS 3786:2023, but AS 3786:2014 remains the version referenced in tenancy legislation across most states as of this writing.
Where a 10-year replacement is the actual law
This varies by state, and it's worth knowing the difference between a legal requirement and general good practice:
- Western Australia: smoke alarms must be replaced every 10 years; hard-wired units by a licensed electrical contractor.
- Northern Territory: smoke alarms must be replaced at 10 years old regardless of type.
- Queensland: alarms manufactured more than 10 years ago, or that fail when tested, must be replaced with compliant photoelectric alarms.
- Other states we researched (Victoria included) don't have a confirmed blanket 10-year replacement law on the books. That doesn't mean an old alarm is fine to leave in place - your specific state's rules may set other conditions, and age-related sensitivity loss is a real, well-understood failure mode regardless of what the law requires. See our compliance guides for what actually applies where your property is.
What we do about it
Every My Safe Home smoke alarm check includes age and condition recording for every alarm on the property, so ageing alarms get flagged and replaced before they become a problem, not after. See our smoke alarm safety checks page or book a check.