5.4 Safety

Operating a biogas plant requires careful attention to the following dangers and safety precautions:

Fire and Explosion Hazard

A gas-air mixture containing 5 to 12% biogas can easily explode with an ignition source at 600°C or higher. Fire danger increases when the gas-air mixture contains more than 12% biogas. Smoking and open flames are strictly prohibited in and around the anaerobic digester units.

Safety of Structures

When designing digester and storage facilities, it is essential to prioritise safety measures to avoid any potential risks to people or animals falling into them. It is recommended to install protective casings for moving parts to prevent accidents.

High Surface Temperatures

It’s essential to be aware that biogas-powered devices can reach high surface temperatures, which can be dangerous and result in burns. This risk is exceptionally high for children and unfamiliar users. To minimise this risk, it’s recommended to use non-heat-conducting materials for the casing of these appliances.

Piping System Precautions

When installing pipes, it is recommended to place them underground at a depth of at least 30 cm. Additionally, it is important to utilise concrete frames and lids to cover water traps or main valves. The safety measurement concerning the health risk of sanitation workers is presented in “Sanitation Quality Standards for Emergencies” on page 6.

Poisoning and Suffocation

Breathing in biogas at high concentrations and for extended periods can lead to poisoning and suffocation. Biogas contains poisonous hydrogen sulphide. To prevent any potential harm, it’s crucial to ensure that all areas with biogas appliances are well-ventilated and to regularly check gas pipes and fittings for gas tightness and protection against damage. It’s also important to supervise gas appliances during operation and educate everyone, especially children, about the potential dangers of biogas.

If the digester needs to be repaired from the inside, it must first be well-ventilated. This is to avoid any risk of poisoning, fire, or explosion due to the gas-air mixture. Conduct the “chicken test” by sending a chicken in a basket to guarantee sufficient ventilation before personnel enter.

For further information, please click on the Materials tab at the top of the page.