A new survey from the American Society of Safety Engineers and Dräger confirms the need for additional education and training in the oil and gas industry about new guidelines that have been recommended for exposure to hydrogen sulfide (H2S).
“The 1ppm (parts per million) Hydrogen Sulfide Threshold: Are You Prepared?” survey uncovered that more than half (53 percent) of safety experts in the oil and gas industry are unaware of new standards set by the American Conference of Governmental Industrial Hygienists (ACGIH) that may help decrease deaths caused by the inhalation of H2S.
A colorless gas commonly referred to as sewer gas and stink damp, H2S remains the leading cause of death among gas inhalation-related deaths in the workplace. Hydrogen sulfide also possesses a unique property of causing olfactory fatigue [temporary anosmia] at concentrations above – depending on the individual – 50-100 ppm. The guidelines, which are not legal requirements, recently recommended by ACGIH for H2S limits include:
- Threshold limit value (TLV): 1 ppm
- Time-weighted average (TWA): 1.4 mg/m3
- Short-term exposure level (STEL): 5 ppm, 7.0mg/m3
Beyond establishing that there is a general lack of awareness surrounding the H2S guidelines, the survey also uncovered other notable observations including:
- The majority (76 percent) of safety professionals who know about the new standards reported no urgency to adopt them, despite the increased safety that can result.
- Companies reported using a variety of alarm levels: 39 percent using 10 ppm and 15 ppm; 35 percent using 5 ppm and 10 ppm; and 15 percent using 10 ppm and 20 ppm.
- Of those companies that have not adopted the new ACGIH guidance, only 24 percent have adjusted their H2S limits within the last three years. Moreover, only 34 percent anticipate adjusting their current H2S limits in the near future.
- Most safety engineers surveyed (64 percent) believe that it is important that instruments are able to detect below 1 ppm. However, only 41 percent believe that a 1 ppm H2S resolution can be seen with accuracy in personal monitoring instruments, and 74 percent are concerned that with the 1 ppm resolution there will be an increase in false readings.
- The majority (70 percent) of respondents think adopting the 1 ppm levels in their workplace would affect worker-protection costs.
- 92 percent of those companies surveyed use personal monitoring instruments as a part of their industrial hygiene program.
- 55 percent use an internal electronic/mechanical docking station to complete checks and record results; 31 percent manually calibrate the instruments via direct flow of calibration gas and record the results; and 14 percent use a third party to conduct calibrations and a manual application of gas for bump tests.
- When survey participants were asked if they were aware of the concerns with using pentane as the only gas source for calibration of catalytic sensors in gas monitoring instruments, a little more than half (53 percent) were unaware of the concerns or that this practice is recommended. 47 percent were aware that methane should be used for periodic testing as well.
Comments from participants also indicated there is significant interest in the issue of H2S safety and health and this is the first step in identifying methods and technologies to assist in preventing injuries and fatalities resulting from H2S exposure.
Unlocking Potential for Safer Work Environments
While the new H2S limits are recommendations and carry no legal obligations at this time, the message is clear. There is a strong belief by agencies, such as ACGIH, that these exposure levels will create a safer work environment. Therefore, it is likely that there will be a wider acceptance and implementation among industrial hygienists and safety professionals as more data becomes available.
Forward-thinking companies will be preparing for the evolution of these standards by considering steps that support these lower limits before they become mandatory. The potential benefits – both in terms of worker safety and cost savings – are significant.