The Ottawa Catholic District School Board was recently fi ned $275,000 for a violation of the Occupational Health and Safety Act relating to an explosion in a school classroom that killed a student who was participating in a class project. The Ottawa Catholic District School Board was charged by the Ministry of Labour (MOL) in January 2012, for failing as an employer to comply with s. 25(2)(a) of the OHSA. The school board ultimately pled guilty to failing, as an employer, to provide information, instruction and supervision to the student’s teacher concerning safe work practices and recognition of the hazards associated with the class project. Two additional charges against the school board were dropped.

On May 26, 2011, students in a Mother Teresa High School classroom were making barbeques out of steel barrels. As a student was cutting a barrel with a hand grinder, the barrel exploded. The student was killed. An MOL investigation found that the barrel the student was using had been washed out with a fl ammable cleaner. The barrel had been stored with its caps closed prior to the class project. This allowed flammable cleaning vapours to accumulate inside the barrel. When the student was cutting the barrel, a spark from the grinder ignited the vapours, causing the explosion. The investigation also found that the school board did not have adequate review and assessment procedures in place to ensure hot work on drums or containers could be carried out safely.

Hot work on containers, including welding, grinding and cutting, is a very hazardous operation. Legislation, including the Ontario Regulations for Industrial Establishments, Fire Code and other nationally recognized codes and standards, contain provisions for hot work, welding and cutting. Section 78 of the Regulations for Industrial Establishments require “that where repairs or alterations are to be made on a drum, tank, pipeline or other container, [it] shall be…drained and cleaned or otherwise rendered free from any explosive, flammable or harmful substance.”

For any hot work such as welding or cutting on a container that may have contained fl ammable or combustible material, the following minimum precautions must be taken:

  • The container’s internal layout must be determined to make sure that fittings such as baffles will not interfere with cleaning or purging.
  • The container must be drained and cleaned using appropriate methods.
  • To determine whether draining and cleaning has made the container safe, its interior must be tested with a combustible gas detector both before hot work begins and periodically during the work.

Some containers cannot be drained and cleaned well enough to make them safe. Such containers may be made safe by purging and inerting with an inert gas, but only if these precautions are taken:

  • Recognized procedures and proper equipment must be used.
  • The oxygen level inside the container must be monitored with an oxygen analyzer and maintained at essentially zero for the duration of the work.
  • Workers must be made aware of the limitations of the inerting process.

Workers should never assume a container is clean or safe and should always make sure that it is made safe and that its safety is verifi ed by testing before any hot work begins. Not following this rule, as was the case in this tragic incident, is likely to cause serious injury or worse.

This conviction and others like it related to incidents involving students, means that schools and school boards must be diligent in developing comprehensive health and safety programs; training workers, including teachers, to identify and report hazards; and eliminating identifi able hazards.