The changes to the standard allow these particular divers the opportunity to use nitrox breathing gas under specified conditions, thereby making a decompression chamber near the dive site unnecessary. The changes impact recreational divers who rely on self-contained underwater breathing apparatus (SCUBA) and dive at depths of 130 feet or less. The revision does not change requirements for other types of commercial divers.
"These changes allow the diving industry to practice innovative diving methods and procedures that help prevent diving accidents such as decompression sickness and embolism," said OSHA Administrator John Henshaw. "Employers of recreational diving instructors and guides covered by this revision can extend their diving operations and focus even more on the safety and health of their workers."
In nitrox diving, a mixture of oxygen and nitrogen gases replaces compressed air as the breathing gas. The partial pressure of nitrogen (a gas that causes decompression sickness) in the gas mixture is lower than it is in compressed air, and that lower pressure allows the diver to remain longer at specified depths than conventional SCUBA divers who breathe compressed air at those depths, and to do so without increasing their risk of decompression sickness.
OSHA based the revision on a variance granted to Florida-based Dixie Divers Inc. in 1999. That variance exempted Dixie from OSHA's decompression-chamber requirements for recreational diving instructors and diving guides, under similar conditions.
