Asbestos in Gas Masks Q&A 

Why did they put asbestos in gas mask filters?

It has been speculated that the inclusion of asbestos in gas mask filters was in response to the need to combat the warfare agent arsine. Later, the filter carbon was impregnated with silver to neutralize the arsenic agents. Another speculation is that it was added as a particle filter due to how fine asbestos fibres are (however it was later replaced by esparto grass).


What is arsine?

Arsine is a highly toxic and flammable gas made up of 1 arsenic atom and 2 hydrogen atoms (AsH3).

Arsine is more deadly than any poisonous gas used during the First World War.


When was asbestos first put in gas mask filters?

It is unknown but has been speculated to be around the late 1920’s to early 1930’s.


When did they stop putting asbestos in gas mask filters?

It is unknown due to different countries stopped at different times, however, it has been speculated that the large majority of countries using the carcinogen had stopped by the late 1970’s.


What filters contain asbestos?

It is difficult to tell due to there is not much information, however it has been speculated that most of the filters from the Second World War contain asbestos.


If I shake my filter and can hear charcoal than it means my filter does not contain asbestos?

No, filters that contain asbestos still contain charcoal.


What filters are safe to use?

It is best to check the expiration date, or look for the manufacturing date and do not use filters older than 10 years.