A surge in the sale and misuse of large nitrous oxide cylinders is putting waste workers’ lives at risk and causing millions of pounds of damage to critical infrastructure used to process Britain’s waste.

Individual Energy-from-waste (EfW) plants can suffer up to six significant nitrous oxide cylinder explosions every day. Operators report that the resulting damage can exceed £1.5 million at a single plant in a year.

There are around 60 EfW plants operating across the UK, treating hundreds of thousands of tonnes of waste each week on behalf of local councils, and many of these facilities are run by members of the Environmental Services Association (ESA). 

Our members have seen that the number of large nitrous oxide cylinders arriving at plants has risen sharply in recent years, despite “laughing gas” being reclassified as a Class C drug in November 2023, making possession illegal without a legitimate reason.

We believe that the reclassification has had an unintended consequence: pushing drug dealers and recreational users away from small, single-use, cartridges towards much larger and more dangerous cylinders. Those found in possession can attempt to claim legitimate use, making enforcement harder.

Nitrous oxide has a limited number of lawful uses, including in medical settings, manufacturing and catering, where it is used as a propellant for whipped cream. Some hobbyists also use it for activities such as motor racing and model rocketry. Outside these niches, legitimate demand is low.

Yet consumer sales of commercial-grade cylinders appear to be rising, judging by the growing volume of them entering the waste stream. The most problematic are large, pressurised cylinders, which weigh more than 2kg and typically contain 600–700g of the highly explosive gas.

These products are easily purchased online with minimal checks by retailers despite rules designed to restrict sales only to legitimate users. In some cases, these products are brazenly sold and marketed bearing imagery associated with drug abuse.

Once emptied, large cylinders remain pressurised and are classed as hazardous waste. They should be disposed of via specialist commercial collections. Instead, many are dumped in parks and roadsides or placed in general rubbish and recycling bins, where they pose a serious risk.

We believe that urgent action is needed. In the short term, regulators and enforcement bodies should ensure retailers carry out meaningful checks to prevent abuse. Mandatory on-cylinder warnings, clearer point-of-sale information and instructions for safe disposal are also needed. The waste sector is also exploring the use of “amnesty containers” at major events alongside secure drop-off points at household waste recycling centres (HWRCs).

In the medium term, Government should ban open retail sales of large cylinders (ie pressurised cylinders with a valve) to constrain their use only to legitimate commercial buyers – with a  proposal and consultation put forward this year. 

In the longer term, once the market for large cylinders is constrained to legitimate commercial users, a deposit-return scheme (similar to that already in place for Patio Gas cylinders) and/or RFID tagging, could be implemented to ensure cylinders are tracked; collected safely and returned for recycling. This should be supported by robust enforcement to ensure that the supply of larger cylinders to retail customers does not transfer to the illicit market. 

Head of Climate and Energy policy at the Environmental Services Association (ESA), Charlotte Rule, said: “Despite the change in law in 2023, explosive nitrous oxide cylinders are littering public spaces and increasingly reaching energy-from-waste facilities, where they threaten workers’ safety and damage vital public infrastructure.

“Our industry has invested in AI detection systems and additional safeguards, but it is like searching for a needle in a haystack and some cylinders inevitably get through.

“To protect workers and infrastructure, and ensure the law is properly enforced, the Government should ban retail sales of large pressurised nitrous oxide cylinders and restrict their use to legitimate commercial purposes.”

John Scanlon, ESA Chairman and Executive Vice President UK, SUEZ Group, said: “The marked rise in nitrous oxide cannister explosions at energy-from-waste facilities suggests that the reclassification of nitrous oxide to a class c drug did little to curb substance abuse and instead simply drove a shift to large cannisters. 

A cursory search online shows these cannisters are widely available, with minimal checks to ensure the purchaser meet minimum age requirements and intends to put the gas to legitimate use. Even worse, the packaging is quite blatantly designed to appeal to those looking to misuse the drug, making a mockery of the law.

The things people throw in their bins continually evolve in response to policy changes and lifestyle trends and in the vast majority of cases, our sector can adapt, we are well used to finding innovative ways to recycle and re-use items and packaging at the end of its life.

However, in this case the cannisters are almost impossible to detect in the waste and we need support from Government to address this issue which risks creating hazardous working conditions for our workers and is costing millions of pounds every year. Given in the region of 70% of UK energy-from-waste facilities operate under local authority contract, treating mainly household waste, this inevitably also impacts the public purse.”

Plant Manager for Cory’s Riverside 1 E-f-W facility in London, David Crawford, said: “Operators like Cory provide an essential service to local communities by managing waste which would otherwise go to landfill. 

We have seen a huge rise in the number of nitrous oxide cannisters coming from our communities in the past few years, which creates significant challenges for our operations team. 

A cannister rupturing is akin to a small explosive going off, causing damage to machinery and making it challenging for us to process waste safely. Last year alone, we identified around 670,000 cannisters present in the waste we processed, of which about 4,000 exploded.”

• A short video reel is available to download here showing explosions occurring in EfW facilities.