This presentation will trace the history of process safety management from prior to the implementation of the OSHA PSM regulation to the current status of the Safety Critical Variable and Safety Critical Equipment programs in Lyondell. Safety Critical Variables and Safety Critical Equipment are risk based management systems that allow for extraordinary operations and reliability management vigilance.

A variable is considered Safety Critical if it's deviation is associated with a certain high level of risk. For each Safety Critical Variable, operating limits, consequences of deviation, and pre-established operator actions are identified. An equipment safeguard is considered Safety Critical if it's disablement can result in a certain high risk. For Safety Critical Equipment, requirements are established for in service verification, functional testing, inspection, maintenance, disablement, and bypassing.

Both of these programs were established as a result of the 1990 Channelview explosion of a 900,000 gallon wastewater tank which resulted in 17 fatalities.