HEPA air purifiers in Australia

A HEPA air purifier is a portable appliance that uses a fan to draw room air through a high-efficiency particulate air (HEPA) filter. This page describes what HEPA means, how "true HEPA" and "HEPA-type" labels differ, how room size and clean air delivery rate (CADR) work, filter replacement, pre-filters and activated carbon, why official bodies caution about devices that produce ozone, noise and energy, what Australian health and environment agencies say about portable air cleaners during bushfire smoke, and what consumer law and the Therapeutic Goods Administration (TGA) say about claims, with links to official sources.

This is a free, non-commercial reference page. It is general information about appliances, official guidance and regulation, not health advice, and it does not describe what air purifiers do for any part of the body or any condition. It does not review or recommend any product, brand or retailer. If you have a health condition or concern, talk to a GP or another registered health practitioner, and follow official advice during smoke events. This page is not affiliated with any business or government body, and listing is not an endorsement. Check current details with the official websites linked below.

The guide

What HEPA means, how purifiers are sized and maintained, ozone and ionisers, noise and energy, official bushfire smoke advice, and the rules on claims.

What HEPA means

HEPA stands for high-efficiency particulate air. One formal definition is the US Department of Energy's technical standard DOE-STD-3020-2015, Specification for HEPA Filters Used by DOE Contractors, which describes a HEPA filter as "a throwaway, extended-medium, dry type filter with a rigid casing enclosing the full depth of the pleats" and states that it "shall exhibit a minimum efficiency of 99.97% when tested with an aerosol of 0.3 micrometer diameter." That standard was written for filters used by US Department of Energy contractors, not for household appliances, but it is the source of the figure most often quoted for HEPA.

"True HEPA" and "HEPA-type" labels

Retail packaging uses several similar phrases, such as "HEPA", "true HEPA", "HEPA-type" and "HEPA-style". No Australian regulator's definition of these phrases was found for this page. EPA Victoria's smoke fact sheet refers to using "a portable indoor air cleaner equipped with a True HEPA (high-efficiency particulate air) filter". A phrase such as "HEPA-type" does not by itself tell you what efficiency a filter has been tested to. The practical test is to ask the seller which standard the filter was tested against and what result it achieved, and to get that in writing.

How a portable air purifier is built

A typical portable unit contains a fan, a filter stack and controls such as fan speed settings and a timer. The filter stack may include a coarse pre-filter, a HEPA or other particle filter, and sometimes an activated carbon layer. The US Environmental Protection Agency (US EPA) says portable air cleaners "are designed to filter the air in a single room or area", whereas furnace or HVAC filters "are designed to filter air throughout a home".

CADR: clean air delivery rate

CADR is a rating of how much filtered air a unit delivers. The US EPA's Guide to Air Cleaners in the Home says "The higher the CADR, the more particles the air cleaner will remove and the larger the area it can serve", and that "Portable air cleaners often achieve a high CADR by using a high-efficiency particulate air (HEPA) filter." The guide gives example particle types for portable cleaners, describing tobacco smoke as representing "the smallest particles", with dust and pollen as larger ones. CADR figures on overseas packaging are often in imperial units, so check the units before comparing models.

Room size and ceiling height

The US EPA advises multiplying the length and width of the room to get its floor area, and notes "The CADRs are calculated based on an 8-foot ceiling" (about 2.4 metres); for higher ceilings it suggests a unit sized for a larger area. EPA Victoria says portable air cleaners "are more effective in rooms smaller than the maximum room size specified by the manufacturer", that "Rooms with high ceilings may require a larger unit than their floor size would suggest", and to "Consider using multiple air cleaners if the only suitable room is larger than the maximum size for a single unit." On placement, EPA Victoria advises to "Operate the portable air cleaner in a well-sealed room with the doors and windows closed" and "away from objects that may restrict air flow."

Filter replacement

The US EPA says "All filters need regular replacement", to "Replace filters according to manufacturer's recommendations", and that "If a filter is dirty and overloaded, it won't work well." It notes that manufacturers "typically recommend replacement every 60 to 90 days", but the interval for any given unit is set by its manufacturer. EPA Victoria adds: "Take care when removing and disposing of the used filter so you don't breathe in trapped particles." Before buying, check the price and local availability of replacement filters, since they are an ongoing cost.

Pre-filters and activated carbon

A pre-filter is a coarse outer layer that catches larger debris before it reaches the main filter; some are washable and some are replaced. A HEPA filter is a particle filter and is not designed to remove gases. For gases, the US EPA says to "choose a portable air cleaner with an activated carbon filter or other filter designed to remove gases", and that "Activated carbon filters can be effective, provided that there is a large amount of material used in the filter." It also notes there is no widely used performance rating for gas-removal filters, and that research has not yet shown other technologies such as plasma, photocatalytic oxidation or UV light to be effective for removing gases.

Ozone generators and ionisers

Some devices sold as air cleaners produce ozone, either intentionally or as a by-product. The US EPA's guide says "Avoid portable air cleaners and furnace/HVAC filters that intentionally produce ozone" and "Ozone is a lung irritant", and warns that air cleaners containing electrostatic precipitators, ionizers or UV lights without adequate lamp coatings have the potential to emit ozone. Its page on ozone generators states that "NO agency of the federal government has approved these devices for use in occupied spaces", that ozone "does not remove particles (e.g., dust and pollen) from the air", and that "EPA does not certify air cleaning devices." In California, the Air Resources Board requires covered indoor air cleaners, including ionizers and electrostatic precipitators, to "produce an emission concentration less than 0.050 parts per million (ppm) of ozone"; that is a Californian rule, not an Australian one. In Australia, NSW Health, Air Quality NSW and the Australian Government's bushfire smoke fact sheet all state that "Humidifiers, negative ion generators and odour absorbers do not remove fine particles in bushfire smoke", and EPA Victoria says they "do not reduce indoor air pollution." If a unit has an ioniser function, ask whether it can be switched off.

Noise and energy

The US EPA says "Noise levels depend in part on the fan speed setting" and, for reference, that "a noise rating around 50 decibels (dB) is roughly the operating noise of a modern refrigerator." A unit sized well above the room can often be run at a lower, quieter fan speed. On energy, the US EPA explains that its ENERGY STAR label means a unit "meets strict energy efficiency guidelines set by EPA" and that "The label does not refer to its air-cleaning effectiveness in any way." ENERGY STAR is a US program; for running cost in Australia, check the unit's rated power in watts at each fan speed.

Bushfire smoke: official Australian advice

Australian agencies include portable air cleaners within wider smoke advice. NSW Health says "consider using an air purifier with a high efficiency particle air (HEPA) filter to remove smoke from your indoor air." The Australian Government fact sheet (December 2020) says "Air purifiers with a high efficiency particle air (HEPA) filter can reduce the number of fine particles indoors" and "To work well, seal the room and match the air purifier to the size of the room it is in." EPA Victoria advises to "use a portable air cleaner with a HEPA filter if you have access to one" and to "Switch air-conditioners to recirculate or reuse air." SA Health advises to "Stay indoors as much as possible", closing windows, doors and vents, and to switch off evaporative systems in smoky air. Always follow current official advice for your area during a smoke event.

What air cleaners cannot do

The US EPA says "Portable air cleaners and HVAC filters can reduce indoor air pollution" but "they cannot remove all pollutants from the air", and that the most effective ways to improve indoor air are to reduce or remove the sources of pollutants and to ventilate with clean outdoor air, with filtration described as "an effective supplement to source control and ventilation." Air Quality NSW also advises avoiding indoor sources of air pollution such as cigarettes, vapes, candles and incense sticks during smoke events.

Claims, consumer law and the TGA

The ACCC says "Claims should be true, accurate and based on reasonable grounds" and "A business must be able to prove a claim of a product having a particular quality or benefit", including claims that a product is therapeutic. Consumer guarantees under the Australian Consumer Law "apply automatically" and a warranty "does not limit or replace these rights." Separately, the TGA says medical devices can be any product "intended by the supplier to be used for a therapeutic purpose in or on human beings", and that "Unless exempt or excluded, all medical devices must be included in the Australian Register of Therapeutic Goods (ARTG)" to be legally supplied. An air purifier promoted for a therapeutic purpose may therefore fall under TGA rules; if a seller makes such claims, ask for the ARTG number and check it on the TGA's ARTG search.

Directory

Official sources on bushfire smoke and portable air cleaners, air cleaner technology, consumer law and therapeutic goods, instead of a list of brands or retailers. Each entry was checked against its own official website.

What is listed. Only government bodies and official agencies whose page could be fetched and checked are included, and each link goes to that body's own page. United States references are included because no equivalent Australian technical guide to household air cleaners was found. The list is not complete and is in no particular order. No retailers or brands are listed.

Not an endorsement. Listing is not a recommendation. This page is not affiliated with any organisation below and does not review, rank or recommend air purifiers, filters or sellers.

Inclusion in this directory is not an endorsement. Links are to official websites as published at the time of checking.

Questions to ask before buying

Plain questions worth putting to a seller, and checking against the specification sheet and written terms, before you buy an air purifier.

What standard was the filter tested to, and what was the result?

Words like "HEPA-type" or "true HEPA" are labels. Ask which test standard applies and for the tested efficiency and particle size, in writing.

What is the CADR, and what room size and ceiling height is it rated for?

Check the units (overseas figures are often in cubic feet per minute and square feet) and compare the rated room size with your room, allowing for high ceilings.

Does the unit intentionally produce ozone, or have an ioniser, and can that be switched off?

The US EPA advises avoiding air cleaners that intentionally produce ozone, and Australian agencies state that negative ion generators do not remove fine particles in bushfire smoke.

How often do filters need replacing, what do they cost and who stocks them in Australia?

All filters need regular replacement. Check the manufacturer's interval, the replacement price and whether filters are readily available locally.

Is there an activated carbon layer, and how much carbon does it contain?

A HEPA filter is a particle filter. The US EPA says carbon filters can be effective for gases provided a large amount of material is used.

How loud is it at each fan speed, and how many watts does it draw?

Noise depends on fan speed. Ask for the decibel rating and power draw at low and high settings, since a purifier may run for long periods.

What claims does the seller make, and can they back them up?

Claims must be able to be proven. If a unit is promoted for a therapeutic purpose, ask for its ARTG number and check it on the TGA's ARTG search.

What do the written terms say about warranty, returns and servicing?

Get the warranty and returns terms in writing. Consumer guarantees under the Australian Consumer Law apply automatically and a warranty does not replace them.

About this page

hepaairpurifier.com.au is a free, non-commercial reference page published by Radiant Life Distributors Pty Ltd, Adelaide. It is general information about appliances, official guidance and regulation, not health advice, and it makes no claims about what air purifiers do for health. It does not review or recommend any product, brand or retailer, and it is not affiliated with, or endorsed by, any organisation listed; listing is not an endorsement. Information was checked against official websites in October 2026; guidance and regulation change, so confirm current details with the organisations linked above and follow current official advice during smoke events.