Automotive Workshop Pit I would suggest you consider the broader terms of the legislation.
(1) A duty imposed on a person by or under this Act requires the person—
(a) to eliminate risks to health and safety, so far as is reasonably practicable; and
(b) if it is not reasonably practicable to eliminate risks to health and safety, to minimise those risks so far as is reasonably practicable.
The standard (I have only seen the free bits) considers explosive atmospheres. There are going to be other risks that you need to manage. A occupational hygienist would be a good person to start with looking at what the hazards are. They can give you direction on how to manage the hazards.
Some examples of possible hazards are carbon monoxide, formaldehyde, black carbon/diesel particulate, noise, lack of oxygen.