Again and again we are faced with questions about how we as a crew can protect ourselves against contaminated cabin air. The following article gives an overview of possible pollutants and suitable protective measures.
Contaminated with what?
In principle, pollutants in different forms can occur as aerosols, gases or vapours. Aerosols are particles such as dust, fibres, smoke or microorganisms (viruses, bacteria, fungi or similar). Gases or vapours are produced when solid or liquid substances reach their specific boiling point and change to the gaseous state.
This can result in e.g. engine oil, hydraulic fluid, de-icing agents etc. in the form of aerosols or gases. Accordingly, a combination filter is required which can adequately filter both particles and gases.
The following pollutants are frequently associated with contaminated cabin air:
- 2-Butanone/Methylethylketone (MEK)
- N-Heptane
- Benzene
- Tributylphosphate
- Trikresylphosphate
- 2-Methylpentane
- N-Hexane
- N-Octane
- N-Decane
- 2-Heptanone
- 2-Butoxyethanol
- Toluene
The list does not claim to be exhaustive, as not all pollutants that cause such symptoms in flight crews and passengers are clearly known yet.
What respirator is suitable for protection?
The following respirators filter a wide range of known pollutants:
- 3M 4279C Half mask protection level ABEK1P3 (price approx. 33 EURO, as of 09.2019)
- Dräger X-plore 3300 Half mask set incl. ABEK1 Hg P3 filter (price approx. 31 EURO, as of 09.2019)
The masks of 3M and Dräger have protection level ABEK1P3. The exact meaning of this level is explained in detail in this Dräger document (in German, page 5ff). Furthermore, Dräger's website can be used to search specifically for certain pollutants, including the pollutants already listed abov
Why only a half mask respirator?
Although eye irritation may occur, we consider the protection of the lungs to be the most important, as most pollutants are absorbed through the lungs. A full face mask, which also protects the eyes, is unsuitable for transport in the flight kit due to its size and mass.
Practicability
With the 3M mask, the filter is already pre-assembled so that it only has to be removed from the packaging and is ready for immediate use. At Dräger, the filters are packed separately, which makes it necessary to assemble them before use.
Owning life
According to the German statutory accident insurance (DGUV), filtering half masks with exhalation valve can be worn for up to 120 minutes before a 30-minute break is required. This value can be reduced by temperatures of more than 28 degrees Celsius and a relative humidity of more than 78 percent. Please refer to DGUV regulation 112-190 (in German, page 147ff) for details on the use of breathing apparatus.
How long can the filter/respirator be used?
Basically applies:
- The end of the service life of gas filters or combination filters used against gases is indicated by odour, taste or irritation upon inhalation.1
- The end of the service life of particulate filters or combination filters used against particles is indicated by an increase in respiratory resistance (inhalation resistance).2
It is recommended to dispose of the used respirator after an incident or to change the filters to make sure that it is fully functional for the next use.