VOC Basics: What They Are and How to Reduce Them Indoors

Volatile organic compounds, often called VOCs, are gases released by many everyday materials and activities indoors. You cannot always see them, but you may notice their odour or experience poor indoor air quality concerns when ventilation is limited or sources are concentrated.

Understanding where VOCs come from is the first step in managing them. In homes, offices, workshops and plant rooms, the best approach is usually a mix of ventilation, source control and the right filtration strategy for the space.

What VOCs are

VOCs are organic chemicals that evaporate easily at room temperature. Indoors, they can build up when fresh air exchange is low, especially after painting, cleaning, installing new furnishings, or storing solvents and fuels in enclosed areas.

Common indoor VOC sources can include:

• •Paints, stains, varnishes and adhesives
• •Cleaning products and disinfectants
• •New carpets, vinyl flooring, furniture and cabinetry
• •Fuel, exhaust and equipment emissions
• •Printing, copying and some maintenance activities
• •Personal care products and air fresheners

It is worth noting that VOCs are not all the same. Different compounds behave differently, and the way you manage them depends on the source, the room use and the ventilation available.

Where VOCs come from indoors

Many indoor VOCs come from materials used in construction, fit-out or routine maintenance. For homeowners, that might mean a freshly painted bedroom, new cabinetry in the kitchen or a garage that shares air with the house. For facility managers, it may involve commercial cleaners, production processes, office furniture or stored chemicals.

Common places to check

• •Storage rooms where solvents, fuels or cleaning chemicals are kept
• •Print rooms, workshops and maintenance areas
• •Recently renovated offices, classrooms or retail spaces
• •Basements, plant rooms and enclosed service areas
• •Garages and attached sheds that may leak odours into occupied spaces

If odours are noticeable, it is sensible to look for the source rather than only treating the air. In many cases, the material giving off the VOCs will continue to do so until it is removed, sealed, isolated or allowed to off-gas under controlled conditions.

How ventilation helps

Ventilation is one of the most effective ways to lower indoor VOC concentration. By bringing in outdoor air and exhausting contaminated indoor air, the system helps dilute airborne gases and odours.

For commercial buildings, ventilation should be considered alongside the relevant design intent and site requirements. AS 1668.2:2024 is commonly referenced for ventilation in Australia, but the final arrangement should be confirmed with the mechanical services engineer or building owner.

Practical ventilation steps include:

• •Increasing outdoor air supply where the system allows
• •Running exhaust fans in bathrooms, kitchens, workshops and chemical storage areas
• •Keeping doors closed to contain strong odour sources where appropriate
• •Purging a space after painting, cleaning or other high-emission work
• •Checking that supply and exhaust paths are not blocked

Ventilation does not remove every VOC source, but it can make a noticeable difference when used correctly and consistently.

Source control is usually the first priority

If a material is releasing VOCs, the most direct way to reduce exposure is to control the source. That might mean choosing lower-emission products, storing chemicals properly or isolating a process from occupied areas.

Source control ideas for different sites:

• •Select products with lower odour and emissions where suitable for the application
• •Keep lids sealed on solvents, adhesives and cleaning chemicals
• •Store chemicals in a ventilated, designated area away from general occupancy
• •Isolate renovation work from occupied spaces where possible
• •Allow new materials to air out before installation if the manufacturer recommends it
• •Maintain equipment so incomplete combustion or process emissions are not worsened by poor upkeep

For homeowners, good habits during renovations can make a big difference. Open windows where practical, keep internal doors shut to unfinished rooms and follow the product instructions on curing or ventilation.

For commercial sites, source control is often a matter of procedure as much as product choice. That can include storage practices, housekeeping, procurement policies and how maintenance tasks are scheduled.

Where filtration fits in

Filtration is useful, but it is important to understand what it can and cannot do. Standard particulate filters are designed to capture particles such as dust, lint, pollen and some other airborne matter. They do not remove every gaseous contaminant on their own.

When VOCs are the concern, activated carbon or other gas-phase media may be used in the right system to adsorb certain gases and odours. The effectiveness depends on the media type, media loading, airflow, contact time and the specific chemicals present.

That means filtration should be chosen for the job:

• •Particulate filters help with dust and visible debris in the air stream
• •Gas-phase filters are used where VOCs or odours are part of the problem
• •Some systems use both, especially in offices, healthcare settings, education facilities and specialist commercial spaces

If you are unsure what your system needs, it is best to assess the source, the airflow path and the filter arrangement before changing products. A filter upgrade that works well for dust may not be enough for gaseous contaminants.

You can also review our products to see the range available, or use how to measure an air filter if you need the correct size for a replacement.

Matching the solution to the space

A small home office, a retail tenancy and a manufacturing area will not need the same approach. The right answer depends on occupancy, ventilation capacity, system design and what is generating the VOCs.

For homeowners

• •Identify the source first, such as paint, new furniture or stored chemicals
• •Ventilate the space as much as practical during and after emission-heavy tasks
• •Use the product instructions for curing, airing out or safe use
• •Check whether your air conditioning or ducted system has a filter stage suited to the problem

For facility managers and contractors

• •Review whether the source can be reduced, isolated or relocated
• •Confirm the ventilation arrangement with the mechanical services engineer where needed
• •Consider whether the existing filtration stage is only for particles or whether gas-phase media is also required
• •Monitor pressure drop where gauges are fitted so filters are not left in service beyond what the system requires
• •Follow the filter and equipment manufacturer instructions for inspection and replacement decisions

Inspection frequency depends on the system, site conditions and dust load, so there is no one-size-fits-all schedule. If the filter is serviceable, regular checks are still important because loading can vary widely between sites.

Practical next steps

If you are dealing with indoor odours or suspected VOC build-up, start with three questions: what is the source, how is the space ventilated, and what does the existing filter system actually do? Once those are clear, it becomes much easier to choose a sensible fix.

A few practical habits can help across most sites:

• •Reduce or isolate emission sources wherever possible
• •Increase ventilation when conditions allow
• •Use the right filter type for the contaminants present
• •Inspect the system regularly and respond to pressure drop readings where available
• •Replace or service components according to the manufacturer instructions

Some filters are designed to be washable - check the product instructions before cleaning or reusing them.

Talk to Total Air Filtration

Total Air Filtration is a family-owned air filter manufacturer and supplier in Hillcrest, Brisbane QLD, and we can help you choose or make the right filters for your application. Call 07 3800 3448 or request a quote, and if you need ongoing support, see filter servicing or commercial filter servicing.