Air Quality Testing
The Critical Importance of Compressed Air Quality Testing in the UK
Compressed air systems are prone to contamination at every stage from intake filtration to point-of-use delivery. Without regular testing, organisations risk non-compliance with stringent UK health and safety legislation, potentially incurring fines or operational shutdowns.
Legal Requirements Under UK Regulations
In the United Kingdom, the Control of Substances Hazardous to Health (COSHH) Regulations 2002 mandate that employers assess and control risks from hazardous substances, including those in breathing air supplied via compressors. Guidance from the Health and Safety Executive (HSE) in document HSG39 emphasises the need for thorough risk assessments, particularly for respiratory protective equipment (RPE).
For breathing air specifically, BS EN 12021:2014 sets the benchmark, requiring contaminants to remain below one-tenth of the workplace exposure limits (WELs) for an eight-hour period. The HSE’s HSG53 further advises testing frequencies based on risk typically every three to six months for high-hazard environments like petrochemicals or diving operations. Failure to comply can result in enforcement notices or prosecutions under the Health and Safety at Work etc. Act 1974.
Beyond breathing air, process air in food and pharmaceutical sectors must align with HACCP (Hazard Analysis and Critical Control Points) principles, as outlined by the Food Standards Agency (FSA). External link: HSE COSHH Essentials.
The table below illustrates the maximum permissible limits of contaminants found in the air as specified in BS EN 12021:1999
BS EN 12021:1999
21% +/- 1%
Why Test? The Hidden Risks of Contaminated Air
Impure compressed air can compromise product integrity, accelerate machinery wear, and endanger workers. Common consequences include:
- Product Contamination: Oil aerosols tainting foodstuffs, leading to recalls (e.g., a 2023 FSA-reported incident in a Midlands bakery).
- Health Impacts: Inhalation of moisture-laden air fosters microbial growth, exacerbating respiratory issues.
- Financial Losses: Downtime from filter blockages or compressor failures, with UK manufacturers estimating annual costs exceeding £500 million (source: British Compressed Air Society).
Regular testing not only averts these issues but also optimises energy efficiency by identifying inefficiencies early. Internal link: Explore our compressor maintenance services.
Understanding Contaminants in Compressed Air Systems
Compressed air purity is measured against three primary contaminant categories, as defined by ISO 8573-1:2010. Our testing employs calibrated, UKAS-accredited equipment to quantify levels precisely.
Key Contaminants and Their Sources
- Solid Particulates: Dust, rust, or wear debris from pipes and valves. Sources include ambient intake air and system corrosion.
- Water (Vapour and Liquid): Generated during compression; excessive levels cause corrosion and bacterial proliferation.
- Oil (Aerosol, Liquid, and Vapour): From lubricants in oil-flooded compressors or atmospheric hydrocarbons.
- Gases and Microorganisms: Trace carbon monoxide, dioxide, or viable bacteria, critical for breathing applications.
A table summarising acceptable limits under BS EN 12021 for breathing air (adapted for clarity):
| Contaminant | Maximum Limit (per m³) | Notes |
|---|---|---|
| Dust & Particulates | 10 mg | Filtered to <5 µm |
| Water | 25 mg | Dew point ≤ -40°C |
| Oil (Total) | 0.1 mg | Includes aerosol and vapour |
| Carbon Monoxide | 20 ppm | <1/10 of 8-hour WEL |
| Carbon Dioxide | 500 ppm | <1/10 of 8-hour WEL |
| Oxygen | 19.5–23.5% | Balance of air composition |
Below is a detailed table of ISO 8573-1:2010 classes:
| Purity Class | Particles (per m³) | Water: Pressure Dew Point (°C) | Oil Content (mg/m³) | ||
|---|---|---|---|---|---|
| 0.1–0.5 µm | 0.5–1 µm | 1–5 µm | |||
| Class 0 | Shall not exceed Class 1 | – | – | Shall not exceed Class 1 | Shall not exceed Class 1 |
| Class 1 | ≤20,000 | ≤400 | ≤10 | ≤ -70 | ≤0.01 |
| Class 2 | ≤400,000 | ≤6,000 | ≤100 | ≤ -40 | ≤0.1 |
| Class 3 | – | ≤90,000 | ≤1,000 | ≤ -20 | ≤1 |
| Class 4 | – | – | ≤10,000 | ≤ 3 | ≤5 |
| Class 5 | – | – | – | ≤ 7 | – |
| Class 6–9 | Not specified | – | – | ≤10–60 | – |
*Note: Microorganisms (ISO 8573-7) require separate viable/non-viable counts, often <100 CFU/m³ for Class 1.
ISO 8573: The Global Standard for Compressed Air Purity
While UK regulations provide a framework, ISO 8573 offers the international gold standard for assessing and classifying compressed air quality. Updated in 2010 (with ongoing reviews as of 2025), it divides testing into nine parts, focusing on ISO 8573-1 for overall purity classes.
ISO 8573 Purity Classes Explained
Purity is graded from Class 0 (most stringent, user-defined) to Class 9 (least pure). Tanair recommends Class 1 or better for sensitive UK industries.
External link: ISO 8573 Overview.
Our services classify your system against these benchmarks, providing a detailed report with recommendations for filtration upgrades.
Our Compressed Air Quality Testing Process
Tanair’s approach is methodical, ensuring accurate, repeatable results compliant with UKAS standards. We conduct tests at the point of use, simulating real operational conditions.
Initial Site Survey
Assess system layout, usage, and risk factors (1–2 hours).
Sampling Collection
Use ISO-compliant samplers for particulates (laser counters), moisture (hygrometers), and oil (impactors/PID sensors).
Laboratory Analysis
Off-site verification for gases and microbes, with results in 7–10 days.
Data Logging
Continuous monitoring for dew point and pressure over 24–48 hours.
Reporting and Certification
Custom report with ISO class assignment, plus a compliance certificate.
For breathing air, we adhere strictly to BS EN 12021 protocols, testing quarterly as per HSE guidance. Frequencies vary: annually for low-risk process air; monthly for critical breathing systems.
Advanced Tools and Certifications
We utilise TÜV SÜD-calibrated instruments, including:
- Laser particle counters (0.1–5.0 µm resolution).
- Oil vapour analysers (detection limit 0.003 mg/m³).
- Microbial samplers for CFU enumeration.
All tests are traceable to national standards, bolstering your audit readiness.
Benefits of Partnering with Tanair for Air Quality Testing
Choosing Compressed Air Systems UK means accessing UK-based expertise with nationwide coverage. Our clients realise:
- Regulatory Assurance: Full COSHH and ISO 8573 compliance documentation.
- Cost Savings: Early detection reduces energy waste by up to 20%.
- Tailored Solutions: Bespoke audits for sectors like automotive or electronics.
- Rapid Response: Same-week scheduling in the South East.
Frequently Asked Questions
How often should I test my compressed air?
Under HSE HSG53, base frequency on risk every 3 months for breathing air, annually for process air.
Does Tanair offer breathing air certification?
Yes, fully aligned with BS EN 12021 and COSHH.
Ready to Ensure Pure, Compliant Air?
Contact Compressed Air Systems UK Today
Do not compromise on safety or quality. Schedule your compressed air quality testing with Compressed Air Systems UK now. Call 01217533330, email orders@tanaircompressors.com, or complete our quick enquiry form.