Working safely inside — Confined Spaces Practice

Sample questions

1. 01L101 lists isolation as part of the safe system of work for a confined space. Which two kinds of isolation does it describe?

   • AFrom substances getting in, and from equipment inside
   • BFrom the mains supply, and from any standby generator
   • CFrom the public, and from other trades on the same site
   • DFrom daylight, and from noise in the surrounding area

   Why: L101 lists two separate elements: isolation from gases, liquids and other flowing materials that could get in from connected plant, and isolation from mechanical and electrical equipment that could operate or be operated while someone is inside. Isolating the mains and a standby feed is only part of the second element, and it says nothing about what could flow in through pipes and ducts.

2. 02A circuit feeding a pump in a chamber has been made dead for the work. What does regulation 13 of the Electricity at Work Regulations 1989 require next?

   • AA sign on the pump stating the date the circuit was switched off
   • BA written permit to work signed by the person who owns the pump
   • CA test of the pump motor insulation before anyone goes inside
   • DAdequate precautions so it cannot become charged during the work

   Why: Regulation 13 requires adequate precautions so that equipment made dead for the work cannot become charged while the work goes on, where danger could arise. Locks, keys and the check for stored energy are how this is met in practice. A sign records nothing about whether the supply can come back, and the regulation does not call for a permit or an insulation test.

3. 03A blank has been fitted in a gas line that runs into a vessel. According to HSE guidance, how is that isolation shown to have worked?

   • ABy noting the time it was fitted on the permit form
   • BBy checking the blank is painted a different colour
   • CBy asking the fitter to confirm it was tightened up
   • DBy testing for the substance the line could carry in

   Why: HSE guidance says the means of isolation must be tested by checking for the substance, to show it has worked. A fitter’s word, a colour or a time on a form records that something was done, not that it actually stopped the gas getting in.