For those of you who know me, I am not one to fear-monger. I tend to be more positive in terms of educating businesses and workers about the value of safety and trying to arm everyoene with information and tools that you need to have a safe working environmet for everyone. Even when I know there is a serious threat on the horizon, I am not one to promote safety out of fear – I am one to inform about how to handle a threat if and when it become imminent in your workplace.
With the preface, I am taking a few minutes to provide you with information about a silent threat, one that is very prevalent in many settings and can be very dangerous and deadly if not handled in the right way.
[Image courtesy of Wikimedia Commons]Hydrogen sulfide canot be distinguished in the air from the oxygen, but unlike oxygen, it is not conducive to life – but rather the opposite. It is a gas that safety officers must be aware of, an ensure their workers are trained in detectimg it and protecting themselves from exposure.
Hydrogen Sulfide: Silent but Deadly
Hydrogen sulfide, with the chemical composition of H2S, is a clear gas that can cause great sickness at low-level exposure and death at high exposure either by amount or time. The good news about this gas is that it is not odorless; it reeks of rotten eggs, which makes it similar to the smell of a natural gas leak. So in that sense,in the absence of a gas monitor, you may be able to detect the presence of hydrogen sulfide in the room or enclosed space and hopefully have the wherewithal to get out quickly.
Hydrogen sulfide can be found naturally and in industrial settings. It is commonly found near refineries, oil and gas exploration facilities or drilling rigs, manure pits, bogs or swamps, hot springs, sewage treatment facilities and manholes, among others. If you or your workers are in a enclosed or semi-enclosed space around these natural or industrial areas, you should always have a working gas monitor available to track for the presence of this gas.
What’s the Big Deal about Hydrogen Sulfide?
What is the big deal with hydrogen sulfide, you ask? Well, the gas has sulfur in it, which already is something for which you should definitely be aware, as sulfur can cause a lot of problems to the human body. The hydrogen sulfide gas is flammable and corrosive, so it’s a double-whammy of fun for safety professionals.
Whether it is lengthy exposure to a small level of gas, or whether it is a very short exposure to intense concentration, it can all be very serious. The gas has been known to cause death in workers who are exposed to it in confidned and/or enclosed areas with or without ventilation.
According to NIOSH, the minimum level of concentration to be considered immediately dangerous to life and health is 100 parts per million. That translates into a .01% concentration of hydrogen sulfide gas, as a 1% concentration is10,000 parts per million. Near-instant death can occur with exposure to as little as a 0.1% concentration of the gas. This is why a monitor is so vitally important to have in any enclosed or confined space at a worksite.
Hydrogen Sulfide: What to Look For
Hydrogen sulfide is a hazard if inhaled, in contact with open flame and/or in contact with skin or eyes. If inhaled at very low levels (about 20 ppm) a worker could experience dizziness, headaches and a disagreeable stomach. After as little as 15 minutes of exposure at this low level, workers could have breathing pattern changes and perhaps some drowsiness. Death may occur at this level with as much as 48 hours of exposure. At a concentration of 500 ppm can bring about staggering and collapse and death could happen after as little as 30 minutes of exposure a this level. Near instant death could accur at a concentration of 1,000 ppm or more.
This gas getting on the skin or eyes can result in eye irritation at very low levels, sensitivity to light and scratches on the cornea of the eye at higher levels, and high levels can also cause suffocation of the body’s cells, similar to what happens with exposure to carbon monoxide or cyanide. Also, as the gas has corrosive qualities, pay attention to any equipment or facilities that are regularly exposed to the gas, as the gas will adversely react to steel, altering the integrity of the equipment and making it less safe to operate.
Hydrogen Sulfide: What to Do
Training and education is paramount in dealing with this gas, whether your workers will be exposed to it regularly or hardly at all. Everyone should at least have an awareness of the gas and how to use and read a gas monitor, and monitors should be placed in every enclosed or confined space where hydrogen sulfide may or will be present. Also, with any chance of exposure, workers should be trained and told to use PPEs with fresh oxygen, and should have their skin covered as much as reasonably possible. All confined or enclosed areas need to have proper ventilation, even vent fans if necessary to ensure that fresh air gets cycled into the space often. The level of training each worker or team will require will depend on the likelihood that the worker or team will be exposed to the gas, and for an extended period of time. Evacuation plans should always be addressed in these situations, and refreshers should be administered at least annually.
If you would like more information about hydrogen sulfide and how to best prepare your workforce for it, take a look at the April 2015 issue of Professional Safety magazine and the article, “Hydrogen Sulfide Awareness” by Greg Gerganoff.