On Friday, January 30, 2015 at 6:54:53 PM UTC, harry wrote:

There's a goverment website on the topic.
http://www.hse.gov.uk/ASBESTOS/essentials/index.htm#a1

I recently asked building control for advice about cutting
a hole in what might be asbestos cement for a ventilator.
They were very helpful - and suggested looking at the HSE
website. This recommended spraying the area to be cut
with shaving foam to catch any fibres that might be
released during drilling, then clean up carefully afterwards.

All very sensible and straightforward.

John