Ozone (O₃) in the yard and garden
High risk for your yardOzone is a WHO and EPA criteria air pollutant; EPA estimates 4,500+ premature US deaths per year attributable to ground-level ozone at current concentrations. EPA has not classified ozone as a human carcinogen; the primary hazard is respiratory and cardiovascular injury. Mechanism: ozone is a powerful oxidant that reacts with polyunsaturated fatty acids and proteins in airway lining fluid, generating secondary toxic products (lipid ozonation products, hydrogen peroxide, hydroxyaldehydes) that trigger neurogenic inflammation, airway hyperresponsiveness, and systemic effects. EPA NAAQS: 70 ppb (8-hour), revised 2015. Short-term exposures at 0.06–0.10 ppm cause measurable lung function decrements (FEV₁ reductions) in healthy adults performing moderate exercise.
What is ozone (o₃)?
The IUPAC name is ozone.
Also known as: ozone, Triatomic oxygen, Ozon, Ozone heavy work.
- IUPAC name
- ozone
- CAS number
- 10028-15-6
- Molecular formula
- O3
- Molecular weight
- 47.998 g/mol
- SMILES
- [O-][O+]=O
- PubChem CID
- 24823
Risk for people, pets,
High riskOzone is a WHO and EPA criteria air pollutant; EPA estimates 4,500+ premature US deaths per year attributable to ground-level ozone at current concentrations. EPA has not classified ozone as a human carcinogen; the primary hazard is respiratory and cardiovascular injury. Mechanism: ozone is a powerful oxidant that reacts with polyunsaturated fatty acids and proteins in airway lining fluid, generating secondary toxic products (lipid ozonation products, hydrogen peroxide, hydroxyaldehydes) that trigger neurogenic inflammation, airway hyperresponsiveness, and systemic effects. EPA NAAQS: 70 ppb (8-hour), revised 2015. Short-term exposures at 0.06–0.10 ppm cause measurable lung function decrements (FEV₁ reductions) in healthy adults performing moderate exercise.
Regulatory consensus
7 regulatory and scientific bodies have classified Ozone (O₃). The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| WHO | — | criteria air pollutant | Ozone is designated as a WHO criteria air pollutant |
| US EPA | — | criteria air pollutant | Ozone is designated as an EPA criteria air pollutant |
| US EPA | — | not classified as a human carcinogen | EPA has not classified ozone as a human carcinogen; primary hazard is respiratory and cardiovascular injury |
| US EPA | 2015 | NAAQS: 70 ppb (8-hour) | National Ambient Air Quality Standards, revised 2015 |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 8 positive / 7 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 8 positive / 7 negative reports) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Category 2A-2B (score: high) |
Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.
Where your yard encounter ozone (o₃)
- Outdoor Air — Vehicle exhaust, Industrial emissions, Power plant discharge
- Indoor Air — Combustion byproducts, Office buildings, Parking garages
Safer alternatives
Lower-risk approaches that achieve a similar outcome to Ozone (O₃):
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Physical/mechanical pest control (IPM)
Trade-offs: More labor-intensive. May not be sufficient for severe infestations.Relative cost: 1.2-2×
Frequently asked questions
Is ozone (o₃) safe for your yard?
Ozone is a WHO and EPA criteria air pollutant; EPA estimates 4,500+ premature US deaths per year attributable to ground-level ozone at current concentrations. EPA has not classified ozone as a human carcinogen; the primary hazard is respiratory and cardiovascular injury. Mechanism: ozone is a powerful oxidant that reacts with polyunsaturated fatty acids and proteins in airway lining fluid, generating secondary toxic products (lipid ozonation products, hydrogen peroxide, hydroxyaldehydes) that trigger neurogenic inflammation, airway hyperresponsiveness, and systemic effects. EPA NAAQS: 70 ppb (8-hour), revised 2015. Short-term exposures at 0.06–0.10 ppm cause measurable lung function decrements (FEV₁ reductions) in healthy adults performing moderate exercise.
What products contain ozone (o₃)?
Ozone (O₃) appears in: Vehicle exhaust (Outdoor air); Industrial emissions (Outdoor air); Combustion byproducts (Indoor air); Office buildings (Indoor air).
Why do regulators disagree about ozone (o₃)?
Ozone (O₃) has been classified by 7 agencies including WHO, US EPA, US EPA, US EPA, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.
See Ozone (O₃) in the outdoor app
Look up products containing ozone (o₃), compare to alternatives, and explore the full data record.
Open in outdoor View raw API dataSources (3)
- US EPA National Ambient Air Quality Standards for Ozone — 2015 Final Rule (2015) — regulatory
- WHO Air Quality Guidelines for Ozone (Global Update 2021) (2021) — regulatory
- ATSDR Minimal Risk Levels for Ozone (2012) — report
Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →