PETROLIA — A chemical spill at Indspec nearly a year ago was caused by human error, but a number of safeguards were not in place, said a new report released today.

There are four lessons from a chemical spill, according to a report released by the U.S. Chemical Safety and Hazard Investigation Board.

Companies that handle dangerous chemicals should be vigilant in documenting changes in the facility, should see that operations include safeguards, should have work practices mirror operating practices, and should have safety reviews that include accurate information.

The board is a federal agency that reviews incidents and makes recommendations but does not issue fines or citations. It began its investigation after the Oct. 11 spill that caused the evacuation of residents in a 2-mile radius.

Indspec found, and today's report confirms, the spill was caused when a storage tank overflowed with the chemical oleum, also called fuming sulfuric acid. Indspec uses oleum to make resorcinol, a product used in tires.

The report said a worker was transferring oleum to the tanks. To speed up the process, the worker started transferring to two tanks at the same time, but only one had automatic shutoffs that would prevent a spill.