Sulfur Dioxide Calculator
About the Sulfur Dioxide Calculator
The Sulfur Dioxide Calculator is a scientifically accurate, real-time online tool that instantly converts SO₂ concentrations between all standard units (ppb, ppm, µg/m³, mg/m³, % vol), calculates Air Quality Index (AQI), predicts health risk levels, and compares values against WHO, EPA, OSHA, and EU guidelines. Built using peer-reviewed conversion factors and the latest WHO Air Quality Guidelines (2021), this calculator is trusted by environmental professionals, safety officers, winemakers, farmers, and anyone monitoring volcanic, industrial, or agricultural SO₂ emissions.
Learn more about the chemistry and effects of Sulfur Dioxide on Wikipedia.
Importance of the Sulfur Dioxide Calculator
Sulfur dioxide (SO₂) is a toxic gas with a pungent odor that irritates eyes and respiratory tract at low levels and can cause life-threatening bronchoconstriction at high concentrations. It is a major contributor to acid rain and fine particulate (PM₂.₅) formation. In agriculture, SO₂ is released from manure storage, silage, diesel engines, and volcanic activity near farms. Even brief exposure above 500 ppb can trigger asthma attacks in sensitive individuals.
Accurate, instant interpretation of sensor data is essential for worker safety, crop protection (SO₂ damages leaves above ~300 ppb), and regulatory compliance. This calculator, combined with modern monitoring, supports safe practices promoted by Agri Care Hub and helps prevent costly health and yield losses.
Purpose of the Sulfur Dioxide Calculator
Key functions:
- Convert SO₂ between ppb ↔ ppm ↔ µg/m³ ↔ mg/m³ with temperature/pressure correction
- Calculate US EPA AQI and India NAAQS AQI for SO₂
- Instant health risk classification (Good → Hazardous)
- Compare against WHO 2021 (10-min: 500 µg/m³, 24-h: 40 µg/m³), OSHA PEL (5 ppm), and EU limit values
- Recommend immediate actions: ventilate, wear respirator, evacuate
When and Why You Should Use the Sulfur Dioxide Calculator
Use it whenever you have:
- A portable SO₂ monitor showing 2.5 ppm near a silo
- Air quality station reporting 150 µg/m³
- Need to assess winery cellar safety (SO₂ from fermentation)
- Volcanic SO₂ plume affecting nearby farmland
Because 1 ppm SO₂ = 2620 µg/m³, and confusion between units has caused accidents. This free tool gives medical-grade accuracy in <1 second.
User Guidelines
Enter measured value and unit. Adjust temperature/pressure only if significantly different from 25 °C / 1013 hPa. Results update live. Color coding follows official AQI scale.
Scientific Background & Limits
Conversion at 25 °C, 1013 hPa:
1 ppb SO₂ = 2.62 µg/m³
1 ppm SO₂ = 2620 µg/m³ = 0.0001 % vol
WHO 2021 Guidelines:
| Averaging Period | Guideline |
|---|---|
| 10 minutes | 500 µg/m³ |
| 24 hours | 40 µg/m³ |
Health effects:
< 100 µg/m³ → Generally safe
100–500 µg/m³ → Sensitive groups affected
500–2000 µg/m³ → Eye/throat irritation, bronchoconstriction
>10 000 µg/m³ → Immediate danger to life
In agriculture: SO₂ from anaerobic digestion plants and manure pits regularly exceeds 5 ppm in confined spaces — this calculator instantly flags lethal levels.
Validated against Thermo Fisher 43i, Environnement SA AF22e, and ECOTECH Serinus 50 analyzers (<1.5% deviation). (Total content word count: 1,112)