The quiet market town of Raunds in Northamptonshire is seldom disturbed by deafening explosions. But one happened in March 2017 when a wrongly discarded battery sparked a fire in an East Northamptonshire Council refuse collection vehicle (RCV) and an explosion that could be heard a street away.
The council said the culprit was identified as a nickel-cadmium (Ni-Cd) battery, and the resulting fire damage-related contamination meant that the six tonnes of material on the vehicle had to be landfilled.
March this year saw a fire at Lincolnshire County Council’s household waste recycling centre, again caused by a discarded battery, but this time from a mobile phone – and only three weeks after fire crews had fought a blaze from two burnt-out laptops at the same site.
These are just two examples. Batteries may look innocuous but they are dangerous things in the wrong place, which all too often is deep in some other waste stream at an MRF or on an RCV.
Quantifying waste industry fires attributable to batteries is problematic because it is often difficult to define a single cause after a blaze. But enough batteries have been in fires for Waste Industry Safety and Health (WISH) Forum to be wary.
Its chair Chris Jones puts the blame for batteries ending up in dangerous situations squarely on the public, who either fail to recycle them at all or put them in the wrong waste stream for collection. Changing this, he says, is a matter for education rather than regulatory change or scientific advances.
Jones said: “We do not have data on batteries causing fires at waste plants because it is quite difficult to know if a fire is started in any particular way. We do know that batteries should not be put in other waste streams, and have long called for better publicity so that people put them in the correct segregated stream instead.”
This is not entirely the public’s fault because many people will see a recycling symbol and assume the item concerned can be put in with any other type of recyclables. Jones said that labelling about how to dispose of batteries is clear, but of course only effective if people trouble to read it before acting.
WISH has asked manufacturers to put a small detection loop in batteries so they can be electronically detected at a MRF. But this could be a mixed blessing, said Jones: “The problem is that, even if manufacturers did it, there are so many batteries mixed in with other waste that our plants would be stopped all the time.”
Batteries in waste streams are also a problem in the US, where the California Product Stewardship Council has tried the complex task of quantifying waste industry battery fires.
It undertook an admittedly small survey of 26 respondents from waste facilities in California, but the results were startling. Among them, 83% had suffered a fire at in the past two years and 65% identified batteries as the cause. Lithium-ion (Li-ion) batteries accounted for 40% of fires, with 15% caused by batteries of unknown type and 10% by other rechargeable batteries. Propane cylinders and unknown causes accounted for the remainder.
One MRF hit by a serious battery fire was Shoreway in San Carlos, which had to be closed for repairs for five months in 2016-17 after a fire where Li-ion batteries were identified as the likeliest cause.
The company decided it needed to understand what had happened and try to identify actions to curb the threat of such fires. Its investigation found that Li-ion batteries are inherently unstable, likely to ignite if damaged and were arriving in single waste streams at a rate of five an hour. “The danger presented by these batteries is predicted to increase significantly in time due to our modern society’s ever-growing demand for mobile and portable devices,” the report said.
To try to crack the problem, the report suggested that only “sturdy and brightly coloured” dedicated battery bags – distributed to households and available at convenient public locations – could prevent people throwing them in with other recyclables or with residual waste.
Differing battery types may, of course, further confuse things. Advice issued by the University of Glasgow on battery disposal by staff and students sets out that Ni-Cd batteries, those that contain mercury and lead-acid batteries are designated as ‘special waste’ because of the hazardous chemicals they contain.
Li-ion batteries are classed as ‘dangerous’ for the purposes of the Carriage of Dangerous Goods Regulations but are not classed as ‘hazardous’, although mixed consignments of batteries should be treated as hazardous.
Given the relentless increase in use of devices with Li-ion batteries, the problem of them turning up where they should not in MRFs and RCVs cannot be expected to improve on its own.
“We do know that batteries should not be put in other waste streams, and have long called for better publicity so that people put them in the correct segregated stream instead.”
There may well be genuine public confusion as to why something that appears to have a ‘recyclable’ symbol on it cannot be put among other materials. Places where batteries can be recycled may be inconveniently located such that, even if the message got across about not putting them in general recycling, they might simply be put into residual waste instead of a dedicated stream.
Although no immediate scientific fix is expected, one could be on the horizon. In August, scientists presented a paper to the American Chemical Society which noted that “Li-ion batteries commonly used in consumer electronics are notorious for bursting into flame when damaged or improperly packaged”.
Researcher Gabriel Veith turned for inspiration to “the weird behaviour of some liquids that solidify on impact”. He explained that Li-ion batteries have a thin piece of plastic to separate their two electrodes. If damaged, the plastic layer fails, allowing the electrodes to come into contact and so cause the battery’s liquid electrolyte to catch fire.
His solution was to mix an additive into the conventional electrolyte to create an impact-resistant material that solidifies when hit, preventing the electrodes from touching. His team used silica suspended in common liquid electrolytes which, on impact, clump together and block the flow of fluids and ions
It may be the future but, for now, a long programme of public education looks essential.