The benzopyrrole volatiles indole and skatole actually have a mothball type smell, and therefore probably do not contribute greatly to the characteristic smell of flatus.
This organization was established in response to severe manpower shortages and was not similar in any respect to the contemporary reserve or mothball fleet.
In late 2012 the 540 employees were given redundancies notices, and the pit owned announced it was to mothball the colliery due to dangerous underground conditions.