1990 ARCO explosion

An explosion at the ARCO Chemical (ACC) Channelview, Texas petrochemical plant killed 17 people and injured five others on July 5, 1990. It was one of the deadliest industrial disasters in the history of the Greater Houston area.

The land along the Houston Ship Channel is a heavily industrialized area, with numerous oil refineries. In the late 1980s and early 1990s, several large industrial disasters occurred in the area, with the largest being the Phillips disaster of 1989, a refinery explosion that resulted in 23 deaths and over 100 injuries. In the community of Channelview, ACC operated a petrochemical plant that was the world's largest producer of the fuel additive methyl tert-butyl ether. On July 5, 1990, employees at the plant were working on restarting a compressor for a 900,000 US gal (3.4-million L) wastewater storage tank at the facility. The tank held wastewater that contained hydrocarbons until it could be deposited in a disposal well. Because the hydrocarbons in the tank could vaporize, the tank had an oxygen analyzer that kept track of the oxygen concentration in the tank and had a nitrogen sweep system to keep the gas inert. However, unbeknownst to the employees, the oxygen analyzer had malfunctioned and as a result, the oxygen level in the tank was at a dangerous level. While restarting the compressor, the gas ignited and caused a large explosion. The explosion completely destroyed the tank and some of the surrounding facility infrastructure, affecting an area the size of a city block.

Following the accident, the Occupational Safety and Health Administration (OSHA) fined ACC about $3.48 million for over 300 violations of the Occupational Safety and Health Act, the largest OSHA fine at the time. Additionally, the company agreed to safety changes at its other three plants in the United States. Damages were estimated to total $100 million; however, ACC spent only $36 million in repairs and upgrades at the Channelview plant including $20 million on safety redundancies.