H2S Gas Monitors
Our single gas H2S monitors are designed to help keep workers safe in hazardous environments by alerting them when the level of hydrogen sulfide reaches the high or low alarm set point. Shop our wide selection of gas detectors and be sure that you will get the best gas detection when using your H2S monitor. You can also purchase other reliable single-gas monitors and multi-gas monitors at PK Safety.
What do H2S monitors detect?
H2S gas monitors are designed to detect hydrogen sulfide (H2S), which is a colorless gas. It also goes by the name sewer gas, swamp gas, stink damp, or sour damp due to its potent rotten smell. Hydrogen sulfide is generated in a range of different industries, including: mining, oil and gas refining, tanning, paper processing, rayon manufacturing, food processing plants, landfills and breweries. The gas can also be found naturally in sewers, manure pits, well water, oil and gas wells, and other confined spaces. It is heavier than air, which causes it to sink to the bottom of these enclosures.
Exposure to hydrogen sulfide is considered extremely dangerous. It is considered highly flammable, explosive, and toxic. Symptoms include eye irritation, headaches, unconsciousness, and even death. The severity of these injuries depends on the length of exposure and how much is in the atmosphere. However, it can be dangerous even at low concentrations.
It remains one of the leading causes of workplace gas inhalation deaths in the U.S. That's why every team should use a hydrogen sulfide gas detector when working in these spaces.
What does a hydrogen sulfide monitor do?
A hydrogen sulfide monitor is designed to detect the presence of H2S in the atmosphere. It comes with an electrochemical sensor that will go off when H2S levels pass certain thresholds, including one high alarm set point and one low point. On some models, users can adjust these thresholds in the settings. When the sensor goes off, it alerts the crew that the air is unsafe to breathe. They can either evacuate the area, provide additional ventilation, or wear protective gear to avoid breathing in the gas.
The monitor measures hydrogen sulfide in parts-per-billion (ppb) or parts-per-million (ppm). The device records the level of H2S in the air when the gas comes in contact with the sensor, which produces an electrochemical reaction. This creates a small electrical current that produces a reading on the sensor.
Users will adjust the settings based on the permissible exposure limits (PEL) of the environment in question. PEL is the maximum amount of a chemical that a worker may be exposed to according to the latest regulations set by the Occupational Safety and Health Administration (OSHA).
The PEL for H2S gases are as follows:
- General Industry Ceiling Limit: 20 ppm
- General Industry Peak Limit: 50 ppm (up to 10 minutes if no other exposure during shift)
- Construction 8-hour Limit: 10 ppm
- Shipyard 8-hour limit: 10 ppm
Where should H2S monitors be placed?
H2S gas monitors should always be worn in the breathing zone, which refers to the nine-inch area around the person's nose and mouth. Many workers will clip the monitor to their hard hat, lapel, or collar. This ensures that the monitor is analyzing the same air the person is breathing, so they will know whether they are in danger. Workers should also make sure the sensor on the device isn't being obstructed by their clothing or equipment.
If the gas monitor is not kept in the breathing zone, it may record inaccurate levels of hydrogen sulfide than the person is actually breathing, considering the gas usually sinks to the bottom of the atmosphere.
It's best to wear portable H2S gas detectors in confined spaces that fit easily onto the person's clothing. Many models come with clips that attach to clothing. It shouldn't sink to the ground or get in the person's way when they're trying to focus on the task at hand. Choose a gas monitor that weighs just a few ounces or less to keep it in the proper position.
If the worker feels that the gas monitor is obstructing their field of view or getting in their way, they may decide not to wear it all together, which puts the entire team at risk of exposure. This equipment should give workers peace of mind, not make it harder to do their jobs.
How can H2S be detected?
Teams should take proper precautions to ensure that workers are not exposed to hydrogen sulfide on the job. It starts with a safety evaluation of the worksite in question. Teams should assess their risk before entering the space. Workers should always have an exit strategy in place in case they need to leave the area in an emergency. If the team suspects that H2S could be in the air or the area doesn't have proper ventilation, everyone should wear a personal H2S gas detector on their person in the breathing zone.
Workers should inspect their gas detectors before entering the space. It should be bump tested to ensure it is functioning properly and calibrated accordingly to record accurate levels of the gas. If the device runs on batteries, it should have a full charge. Many teams will leave their gas detectors in a docking station when they are not in use. The station automatically charges the device, while calibrating the device for the most accurate levels. It can also perform a H2S monitor bump test before every shift. Workers should also inspect the sensor to make sure it's free of dirt and debris that can obstruct the signal.
If the team doesn't have access to a docking station, they will have to manually charge and bump test their gas detectors. A bump test is a simple way of making sure the sensor on the device is working properly. It's done by exposing the monitor to a known concentration of the target gas, such as 25 ppm H2S, usually for at least one minute. If the monitor goes into alarm it is working properly.
Once workers enter the space, they should watch out for warning signs that H2S is in the air. The alarm should go off if the gas reaches the threshold. It may issue a vibrating alarm or a flashing light in addition to the sound of the alarm. This increases the chances that workers respond, especially if they are working in a noisy area or have low visibility.
Everyone in the space should also watch out for early warning signs of exposure to H2S, including nausea, coughing, loss of smell, or a rotten or potent smell. Prolonged exposure or high concentrations can also lead to fainting or sudden collapse.
If a threat is detected, workers should evacuate the space as quickly as possible to avoid breathing in the toxic gas. It may be as simple as walking outside to get a fresh breath of air. The sensor on the device may need a few minutes to reset once the worker leaves the area in question.
H2S gas monitors are designed to help workers avoid exposure to the harmful gas. No one should have to worry about compromising their health when entering a workspace. You will find everything you need to detect H2S at PK Safety. Contact one of our safety experts to learn how to choose the right confined space safety gear and hydrogen sulfide detector for your team.