No room in the workplace shall be so overcrowded as to cause risk to the health or safety of persons at work in it.

Without prejudice to the generality of paragraph 1, the number of persons employed at atime in any workroom shall not be such that the amount of cubic space allowed for each is less than 11 cubic metres.

In calculating for the purposes of this Part of this Schedule the amount of cubic space in any room no space more than 4.2 metres from the floor shall be taken into account and, where a room contains a gallery, the gallery shall be treated for the purposes of this Schedule as if it were partitioned off from the remainder of the room and formed a separate room.