What's in a room spray?

The label often just says 'parfum', but that word covers a mixture of dozens of substances. A study of 25 scented products measured 133 different volatile organic compounds, an average of 17 per product. Of these, only ethanol was listed on a product label.

Does it have a scent?

It has a light, fresh mint-menthol note, added so you can tell when you've sprayed. The ingredients on the label: Aqua, Bacillus Ferment, Perfume. It doesn't leave a heavy smell in the room.

Does it help with bad odours too?

Yes. Bad odours are produced by microorganisms that feed on residue. The probiotics in Air Biotics use up these microorganisms' food sources, helping to reduce how much odour forms. Room sprays, on the other hand, just add a new scent on top of the smell.

Indoor air · 5 min read · 3 October 2026

What do room sprays add to indoor air?

Three studies on the volatile compounds released by scented products, what the label leaves out, and how fragrance affects other people.

C₁₀H₁₆

Limonene

In short

1133 different volatile compounds were measured in 25 scented products; only one was listed on a label.
2In a representative survey, more than a third of people reported problems from scented products.
3Masking a bad smell with perfume means adding a second load to the air.

One spray, dozens of compounds

The label on a room spray usually says 'parfum' or 'fragrance'. That single word covers a mixture of dozens of substances. A study in the US measured the emissions from 25 scented products, made up of air fresheners, laundry products and cleaning products. In total, 133 different volatile organic compounds were found, an average of 17 per product.

24 of these compounds were classified as toxic or hazardous under US regulations, and every product contained at least one of them. Of the 133 compounds, only ethanol was listed on a product label. Emissions from products labelled 'natural' or 'green' were not markedly different from the others.

It keeps changing in the air

Terpenes such as limonene in air fresheners react with ozone present in indoor air. This reaction can produce secondary pollutants such as formaldehyde, as well as ultrafine particles. In other words, as long as a sprayed scent stays in the air, it keeps turning into other substances.

A scent you like may bother someone else

In a survey of 1,136 adults representative of the US population, 34.7% of participants said they experienced problems such as migraines or breathing difficulties when exposed to scented products. 20.2% said that when they entered a workplace where air freshener had been sprayed, they left as quickly as possible.

If there's a baby, a family member with asthma or someone sensitive to scents at home, these figures matter even more.

What can you do?

A bad smell has a source: grease that has soaked into the curtains, urine in the litter tray, a damp filter. The lasting solution is to find that source.

01First find where the smell is coming from: fabric, drain, filter or damp?
02Clean or wash the source; fabrics are the surfaces that hold on to smells the most.
03Air the room, and lower the humidity if it's high.
04If you use a product, choose one that isn't heavily perfumed and has no propellant.

Questions

What's in a room spray?: The label often just says 'parfum', but that word covers a mixture of dozens of substances. A study of 25 scented products measured 133 different volatile organic compounds, an average of 17 per product. Of these, only ethanol was listed on a product label.
Does air freshener turn into other substances in the air?: Yes. Terpenes such as limonene react with ozone in indoor air; this reaction can produce secondary pollutants such as formaldehyde, as well as ultrafine particles.
Does it have a scent?: It has a light, fresh mint-menthol note, added so you can tell when you've sprayed. The ingredients on the label: Aqua, Bacillus Ferment, Perfume. It doesn't leave a heavy smell in the room.
Does it help with bad odours too?: Yes. Bad odours are produced by microorganisms that feed on residue. The probiotics in Air Biotics use up these microorganisms' food sources, helping to reduce how much odour forms. Room sprays, on the other hand, just add a new scent on top of the smell.

Sources

All literature →

01
Fragranced consumer products: Chemicals emitted, ingredients unlisted
Steinemann AC, MacGregor IC, Gordon SM et al. (2011). Environmental Impact Assessment Review 31(3): 328-333
doi:10.1016/j.eiar.2010.08.002
Finding · Laboratory study25 fragranced products, including air fresheners, cleaning and laundry products, were measured giving off 133 different volatile organic compounds, an average of 17 per product. 24 of them were classed as toxic or hazardous under US law. Of the 133 compounds, only ethanol was listed on any label. Emissions from products labelled 'green' were not clearly different from the others.
02
Cleaning products and air fresheners: exposure to primary and secondary air pollutants
Nazaroff WW, Weschler CJ (2004). Atmospheric Environment 38(18): 2841-2865
hero.epa.gov/hero/index.cfm/reference/details/reference_id/57058
Finding · ReviewTerpenes in cleaning products and air fresheners can react quickly with ozone in indoor air to form secondary pollutants such as formaldehyde.
03
Fragranced consumer products: exposures and effects from emissions
Steinemann A (2016). Air Quality, Atmosphere & Health 9(8): 861-866
doi:10.1007/s11869-016-0442-z
Finding · SurveyIn a survey of 1,136 adults representative of the US, 34.7% of participants reported health problems such as migraines and breathing difficulties when exposed to fragranced products. 20.2% said that if they entered a workplace sprayed with air freshener, they left as quickly as possible.
04
The use of household cleaning sprays and adult asthma: an international longitudinal study
Zock JP, Plana E, Jarvis D et al. (2007). American Journal of Respiratory and Critical Care Medicine 176(8)
pubmed.ncbi.nlm.nih.gov/?term=Zock+2007+household+cleaning+sprays+adult+asthma
Finding · Cohort studyMore than 3,500 adults in 10 countries were followed. Among those who used cleaning sprays at least 4 days a week, the risk of doctor-diagnosed asthma was 2.11 times higher. The risk was greatest with glass, furniture and air freshener sprays.

These studies were not carried out with Air Biotics. What we say about the product is limited to what is written on its packaging; Air Biotics is not a disinfectant.

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