Work in confined spaces usually requires authorisation under a Permit to Work process – please verify this with your host before commencing any work in confined spaces.
A confined space is a place which is substantially enclosed (though not always entirely), and where serious injury can occur from hazardous substances or conditions within the space or nearby (e.g. lack of oxygen due to the presence of argon).
Confined spaces are defined as being any place which presents a foreseeable risk of harm to any person in that place because of its enclosed nature caused by either;