1. Details and Introduction
EN 12021:2014 is a European Standard that specifies the requirements for the quality of compressed gas used in respiratory protective devices. It ensures the safety and quality of breathing air for various applications, including self-contained breathing apparatus (SCBA), airline systems, and escape devices. The standard aims to minimize health risks by setting strict limits on contaminants such as carbon monoxide, carbon dioxide, oil, and humidity, and ensuring the air is free from odour and taste.
Key points:
- Purpose: To ensure the quality of compressed air for breathing apparatus meets safety standards and protects human health.
- Scope: Applies to compressed air used in surface and underwater applications, including synthetic air and gas mixtures like Nitrox, Heliox, and Trimix.
- Regulatory Context: Employers must comply with standards like COSHH (Control of Substances Hazardous to Health) in the UK to ensure compliance.
2. Applicable Products
EN 12021 applies to a wide range of products and systems that use compressed air for breathing, including:
- Self-contained breathing apparatus (SCBA): Used in fire fighting, industrial settings, and diving.
- Airline breathing systems: Supplied through hoses or tubes for industrial or emergency use.
- Escape devices: Emergency breathing equipment for hazardous environments.
- Synthetic air systems: Systems producing air mixtures for specialized applications.
- Gas mixtures: Includes Nitrox (oxygen-enriched air), Heliox (oxygen-helium mixtures), and Trimix (oxygen-helium-nitrogen mixtures).
3. Test Methods and Parameter Values
EN 12021 specifies the permissible levels of contaminants and other parameters to ensure air quality. Below are the key test parameters and their maximum allowable values:
| Parameter | Maximum Permissible Value | Notes |
|---|---|---|
| Oxygen | (21 ± 1)% by volume (dry air) | Ensures breathable air quality. |
| Carbon Monoxide | ≤ 5 ml/m³ | Prevents toxic exposure. |
| Carbon Dioxide | ≤ 500 ml/m³ | Limits respiratory irritation. |
| Oil | ≤ 0.5 mg/m³ | Prevents lung damage from oil droplets. |
| Water Content | ≤ 50 mg/m³ at 40–200 bar; ≤ 35 mg/m³ above 200 bar | Prevents condensation and freezing. |
| Dew Point | ≥ 5°C below ambient temperature or ≤ -11°C if unknown | Prevents moisture-related issues. |
| Odour/Taste | Free from unsatisfactory odour or taste | Ensures user comfort and safety. |
4. Notes
- Compliance Requirements: Employers must ensure regular testing and maintenance of compressed air systems to meet EN 12021 standards. A risk assessment is required to determine the frequency of testing, typically every 3 months.
- Health Risks: Failure to comply can lead to serious health issues such as carbon monoxide poisoning, industrial asthma, or COPD.
- Testing Frequency: The frequency of testing depends on the system’s usage, ambient conditions, filtration efficiency, and maintenance schedules.
- Additional Standards: EN 12021 also references other international standards like the Pharmacopée Européenne and DIN EN ISO for broader compliance.
