The dangers in rubbish: Part 3/4

What makes nitrous oxide canisters so dangerous?

The increasing use of nitrous oxide has significantly raised the risk in Frankfurt am Main due to partially non-empty canisters. In 2024, Frankfurter Entsorgungs- und Service GmbH (FES) collected over 6,000 nitrous oxide canisters from public spaces, sorted out misthrows, received them at recycling centers, temporarily stored them, and passed them on to a service provider for proper disposal. This alone incurred costs of around 180,000 euros last year.

The danger potential of nitrous oxide canisters:

1. Nitrous oxide canisters can explode, causing injuries to people and severe damage to waste-to-energy plants and garbage trucks.
2. Nitrous oxide (N2O) is a greenhouse gas that is about 265 times more harmful to the climate than carbon dioxide (CO2).

FES Managing Director Dirk Remmert says: “We estimate that every fifth nitrous oxide cartridge is not completely empty. The potential danger to people and facilities is enormous. If such a canister were to explode in a waste-to-energy plant and, as has happened in other German facilities, damage the grate or refractory lining, the plant would be out of operation for the duration of the repair. This would prevent any waste from being accepted and burned.”

Nitrous oxide cartridges are accepted free of charge at FES recycling centers and temporarily stored until collection by a service provider. A deposit system would particularly reduce the problem of nitrous oxide canisters in public spaces.

Managing Director Remmert continues: “A nationwide deposit requirement for gas cartridges from 200 ml would help. Ultimately, it’s also about disposal safety. The more sorting and treatment facilities are damaged by exploding nitrous oxide cartridges, the higher the likelihood of temporary outages.”

At the Heddernheim waste-to-energy plant (MHKW), gas canisters explode several times per shift (most of which are estimated to be nitrous oxide canisters). Larger explosions can cause serious damage. So far, the MHKW Frankfurt has not suffered major damage. However, massive deflagrations, as occurred last week, can also push the flue gas quickly out of the boiler, so that the residence time is insufficient to “burn off” the flue gas. This can lead to temporarily high carbon monoxide levels; in the worst case, even exceeding emission limits.