Staying Compliant With Biogas Safety Regulations

A diagram showing that livestock waste, crops, wastewater, and food waste, when put through an anaerobic digester, results in either digestate which can be used to make fertilizer and livestock bedding, or biogas, which generates heat and electricity and produces biomethane, which is used for fuel.

Biogas, a byproduct of the anaerobic digestion process, is a highly valuable renewable energy source. However, it can also be dangerous to humans, wildlife, and the environment as it contains a mix of carbon dioxide (CO2), methane (CH4), hydrogen sulfide (H2S), ammonia (NH3), and other secondary impurities.

If not properly controlled and monitored, biogas can result in explosions, asphyxiation, and/or high-pressure leaks, so it’s crucial for facilities to maintain the threshold limit values of these hazardous gases. Additionally, the renewable energy production industry remains under nonstop pressure to minimize greenhouse gas releases.

Businesses have turned to various biogas monitoring technologies to comply with EPA requirements, including using on-person detection equipment, drones, satellites, and other devices that continually monitor for excessive emissions.

EPA Safety Requirements & Guidelines

The EPA has six primary guidelines relevant to biogas production and anaerobic digestion. These are outlined below:

Methane Flammability & Explosion

Methane (CH4) is a highly flammable gas when its atmospheric concentration is between 5 and 15%, and accumulates in cramped spaces that lack adequate ventilation.

During biogas production, methane concentrations typically range between 50 and 75%, which is above the upper explosive limit (UEL) of 15%. Methane concentrations become dangerous during biogas production when they leak outside of the digester, system piping, or containment area and mix with the air outside. When this happens, the risk of methane reaching that 5 to 15% range is greater.

To prevent methane-related explosions, the EPA requires that businesses implement continuous biogas monitoring devices outside the production system to ensure that methane levels remain safe. When leaks develop, monitors activate alarms to alert operators of changing CH4 levels so that appropriate action can be taken.

Along with permanent usage of methane detection devices, worksite smoking/vaping prohibition, routine leak detection inspections, and appropriate fencing and signage are all required.

Explosive Gas Hazard Zones

Anaerobic digesters on a farm

An explosive gas hazard zone is an area where flammable/explosive methane concentrations may possibly develop. They are typically located around the joints between digestor tanks, containment covers, piping, and related system components. However, vaults, pits, enclosures, and buildings that house biogas production equipment are also potential hazard zones.

The National Fire Protection Association classifies hazard zones into three levels in its National Electrical Code:

  • Level 1/Class I, Division 1: The work area is consistently at risk of explosions because the environment is exposed to an explosive mixture during regular operation or because there is a higher risk of leaks or equipment breaking down. This level has the most restrictions.
  • Level 2: Class I, Division 2: The work area is not normally at risk of explosions. In this environment, an explosion would only occur due to “a containment breach, accidental rupture, or abnormal equipment operation” or if the worksite is near a Class 1, Division 1 site.
  • Unclassified: The risk of an explosion in this environment is extremely low.

Workers inside hazard zones must continuously be aware of possible ignition sources, including cigarette lighters, vapes, welders, pilot flames, electrical outlets, cell phones, computers, radios, light switches, and more. It’s highly important to tightly control all possible ignition sources because it’s not always possible to know about or control leaking gas.

The EPA requires workplaces to use appropriately rated electrical equipment, fixtures, and devices. So, if a worksite is classified as Class I, Division 1, the site must only use equipment, fixtures, and devices rated Class I, Division 1.

Toxic Gases

Some gases can become Immediately Dangerous to Life & Health (IDLH), meaning they can become lethal to humans and animals within seconds of exposure at specific atmospheric concentrations.

A few dangerous byproducts commonly created during biogas production are:

  • CO2 (carbon dioxide): Odorless, colorless, heavier than air, asphyxiant, IDLH at 40,000 ppm (becomes toxic at 5% concentrations).
  • H2S (hydrogen sulfide): Colorless, heavier than air, can smell like rotten eggs, IDLH at 100 ppm.
  • CH4 (methane): Odorless, colorless, lighter than air, simple asphyxiant, highly explosive (no exposure limits if the oxygen levels exceed 19.5%).
  • NH3 (ammonia): Colorless, lighter than air, asphyxiant, irritant, IDLH at 300 ppm.

All asphyxiant, corrosive, explosive, and toxic gases must be handled and used correctly to avoid death, injury, or irreversible and/or delayed health effects.

Personal Detection Devices

A yellow gas monitoring device leaning up against a respirator. Next to the monitoring device is an orange hard hat and a pair of black gloves.

Hand-sized personal gas detectors can be clipped on collars or placed in pockets to constantly measure the gaseous composition of the atmosphere surrounding workers. A visual and audible alarm is activated if any gas is detected in undesirable amounts, signaling the individual to vacate the area. These highly effective detection devices are affordable and add a layer of prevention and safety for all biogas industry workers.

Permanent Gas Detection

Biogas production facilities must have properly functioning, permanent gas detectors with visible alarms. They are to be positioned to prevent unintentional worker entry into hazardous zones, like entryways to high-solid vessels, digestor pump rooms, post-digestion separation buildings, and confined spaces where gas is likely to accumulate. The detectors will provide visual and audible alarms if certain gases exceed their threshold limits. All detectors must be thoroughly maintained and calibrated to ensure accuracy.

Toxicity Hazard Zones

Like explosive gas hazard zones, toxicity hazard zones are commonly located around the joints and seams between different components of a biogas production system. This can include the general atmosphere, temporary enclosures, work pits, vaults, permanent buildings, or other structures used in biogas processing.

Additionally, areas where reactors have been opened, or any related piping or equipment has been disassembled will be labeled toxicity hazard zones until they have been adequately off-gassed and ventilated.

Staying Compliant With the EPA’s Biogas Safety Regulations

As mentioned in previous sections, gas detection devices are essential to complying with EPA rules and regulations.

If you’re looking for reliable gas monitoring devices, we have had good experiences with QUBE and Blackline Safety devices. They are cloud-based remote detection solutions that keep connected workers safe and help to maximize operational efficiency.


the QUBE automated greenhouse gas detection monitoring system

The QUBE gas detection solution helps workers detect, quantify, and reduce greenhouse gas emissions, including sulfur dioxide, carbon monoxide, methane, and volatile organic compounds. QUBE technologies use physics-guided algorithms to determine a gas leak’s precise location, class, and quantity, which helps operators prioritize leaks.

Additional benefits of QUBE include:

  • Continuous/real-time leak monitoring with no need for constant human oversight
  • Rugged design to ensure durability
  • Customizable alerts
  • Powerful AI-driven, cloud-based analytical dashboard with worldwide usability
  • Automated emissions reports with exporting capabilities
  • Solar-powered with no need for an external power source
  • Its rechargeable battery can last for over 5 years
  • Gas sensors are individually calibrated
  • Can be installed in around 20 minutes

The QUBE system is also designed to improve its efficiency over time, allowing operators to gradually reduce the number of monitoring devices needed for a given facility.

Blackline Safety

Blackline Safety's G7 EXO gas monitoring device
The G7 EXO

Blackline Safety products have advanced, cloud-based technologies that ensure lone worker protection, continuous gas leak detection, and expanded data analytics. Blackline Safety solutions include the following:

  • G6 Gas Detector: Portable, cloud-connected, detects one type of gas, maintenance-free operation for one year.
  • G7 Single-Gas: Upgraded G6 wearable device with cloud connectivity, advanced data analytics, and reporting capacity.
  • G7 Multi-Gas: Same features as the G7 Single-Gas, but capable of sensing up to five distinct gases.
  • G7 Multi-Gas Pump: Gives operators superior control over confined space entry and leak checks.
  • G7 EXO: The industry’s only direct-to-cloud area gas monitor; designed to withstand brutal climatic conditions.
  • G7 Lone Worker: Wearable, pocket-sized device that keeps connected workers safe in remote locations.

All Blackline Safety devices provide instant alerts whenever an accident occurs, allowing the fastest possible response times. They also help reduce false alarms, are intrinsically safe in explosive atmospheres, and precisely map a worker’s location if an accident occurs.

Find the Gas Detection Products You Need Today

Archview Services is a specialty products and services provider helping businesses in many industries throughout the Midwest. We help our customers in the biogas industry by offering customizable data storage and reporting platforms, safety consulting, on and off-site training, site remediation, and high-quality confined space entry and gas monitoring equipment, including QUBE and Blackline Safety products. All products and equipment are available to purchase or lease.

Please contact us today to learn more about our available gas detection products or to schedule a consultation.