Originally created in 1994, ANSI/ASSP Z390.1, Accepted Practices for Hydrogen Sulfide Training Programs, was developed to establish appropriate hydrogen sulfide (H2S) safety training for those working in the oil and gas industry.
The need for such a standard arose from the fact that hydrogen sulfide is one of the primary hazards associated with oil and gas operations. Without proper training on what to do when encountering the gas, human exposure to hydrogen sulfide can have serious health consequences and even lead to death, emphasizing the importance of the ANSI/ASSP Z390.1 standard.
Although the original intent of the standard was to address hazards associated with oil and gas, over time the Z390.1 committee recognized that petrochemical plants, paper mills, research laboratories, municipal sewer systems and others have hydrogen sulfide hazards as well. This led the committee to publish a 2017 revision (ANSI/ASSP Z390.1-2017) of the standard, which incorporates information to accommodate the needs of other industries. In addition, changes were made to update references to technology, as well as editorial cleanup and reorganization to make the standard more user-friendly.
The most significant change in the revised version is an update to the time-weighted average threshold limit values (TLV-TWA). The American Conference of Governmental Industrial Hygienists (ACGIH) has changed is established TLV-TWA from 10 ppm to 1 ppm. Since the standard’s previous version anticipated training based on the 10 ppm measurement level, Z390.1 was revised accordingly.
ANSI/ASSP Z390.1-2017 provides the flexibility for instructors or instructing organizations to use their own judgment to determine the appropriate action levels based on state, federal and local regulations, consensus standards and local safety assessments. This allows individuals and organizations to assess the safe action level depending on the work setting. Furthermore, the revision states that workers should only be trained on material that is applicable to their potential exposure.
One way in which the revised standard is more stringent is in the area of visitor safety training. In the past, when VIPs visited certain locations with potential hydrogen sulfide hazards, they would receive a 15-minute presentation on hydrogen sulfide safety, then be allowed on to the drill floor. ANSI/ASSP Z390.1-2017 does not approve of this practice. Instead, the Z390.1 committee advises anyone visiting a site with potential hydrogen sulfide hazards to take a full four-hour class prior to their visit.
In addition, it is recommended that anyone working in a location where a hydrogen sulfide hazard has been identified be trained to an established minimum standard. Z390.1-2017 establishes four hours of training, which includes discussion of properties and characteristics of hydrogen sulfide, gas detection, respiratory protection and contingency plans.