Food waste is an emotive issue. So, it seems, is the use of liners. There are those that swear by them and will only use a food waste collection service if they are provided. There are others that think they are a waste of resources and money and prefer to line their caddy with paper already destined for recycling. Ours has been a liner household ever since I returned from a waste trade show with some rolls of (free) liners and my husband exclaimed “how much more civilised” it was. Similarly, my 83-year-old father who’s always refused to collect his food waste, is now putting it out with the best of them ever since Monmouthshire County Council started providing free liners to his door.

But these are just my immediate experiences and my Dad’s house had been conspicuous in its abstention come collection day, suggesting that the majority of the other householders had bought into the scheme already. Equally, if my household runs out of liners, we don’t suddenly stop using the food waste bin. So, do liners really make that much of a difference? And why are there such different attitudes amongst councils?

During 2007-2008, WRAP supported 19 local authorities to carry out food waste collection trials. With the exception of two rounds in Surrey, all trial areas were provided with compostable cornstarch or potato starch liners. Various methods of replenishment were employed: blanket drops; distribution through community centres; upon request; token systems; and through approved stockists. It was calculated that, on average, each household used 2-3 liners per week.

A report written alongside, ‘Food Waste Collection Trials – use of liners for kerbside containers and kitchen caddies’, revealed that the yields per household were lower for the rounds where the liners had not been provided, although ‘the difference in yields were fairly small and these lower yields might be attributable to other factors so these results are only indicative’. Attitudinal surveys, however, showed that the vast majority of residents and collection crews found the liners helpful: ‘Feedback from the collection crews was that they much preferred the collection rounds where liners were provided, as they considered that collections were easier and cleaner.’

Yet, contamination and costs can be barriers to introducing liners. WRAP noted that through providing clear communications, “treatment facilities receiving food waste from the trial areas reported very low levels of contamination”, but contamination stemming from the belief that if you can use compostable liners then surely a carrier bag is OK can be a problem. As Trelawney Dampney from Eco Composting has pointed out: “It doesn’t make much of a difference whether the food waste arrives bagged or unbagged from an operational point of view, but if it is not bagged then this reduces the chances of getting rogue plastic bags into the compostable product.”

Indeed, Gloucester City Council, since introducing food waste collections in February 2009, has never offered compostable liners and, in fact, insists that residents line caddies with only paper bags, newspaper or paper towels because of the chance of contamination. Sinead Tunney, Neighbourhood Services Manager at Gloucester City Council, says the decision was made after visiting the plant in Dymock where the waste was to be reprocessed and seeing workers hauling out plastic bag after plastic bag: “The problem is that it’s very difficult to differentiate between different types of bags, between degradable, biodegradable and compostable. So we decided from the off to get people using paper or kitchen towels, rather than risk the possibility of our loads of food waste being rejected and sent to landfill.”

If collection crews spot a liner, the household is contacted by the council. Tunney reports that apart from a ‘few grumbles’ from a couple who had recently moved from another area where liners were provided, residents have been accepting of the no-liner policy and participation is ‘good’.

Meanwhile, in West Devon, using liners as part of a pilot in 2007 “helped with participation but also brought their own problems”, according to Jane Savage, Waste Reduction and Recycling Officer. “Residents requested [the liners] by a note on their food caddies and these were not always responded to by crews.”

When the council rolled out the service across the borough, to combat replenishment issues it decided to provide only an initial supply of liners. Reports from its food waste outlet that it “prefers the food loose, wrapped in paper or in liners as a last alternative” was also a deciding factor.

This change in provision did, however, disrupt the service, says Savage: “Although we never did any specific studies on whether not continuing to supply liners free had an effect on participation, anecdotal evidence suggests it did.”

WRAP’s report concurs with such anecdotal evidence: ‘If free liners are provided at the outset of a scheme’, it notes, ‘the introduction of charges is likely to have an adverse effect on the performance of the scheme.’ Indeed, in two of the trial areas where liners had been provided, 38 per cent of respondents stated that they would discontinue using the service if no more liners were provided. (Indeed, my father’s proviso is the free supply, and once he’s out he’ll stop.)

But supplying liners indefinitely can be a bit daunting. At approximately £3 per household per year, according to WRAP figures that assume 2.3 liners are used per week, it is a considerable investment. Evidence suggests, though, it can be done for less. Bristol City Council was the UK’s first city to offer food waste collections to all residents and considered supplying liners to its 150,000 households. And although Councillor Gary Hopkins explains, that “it wasn’t the cost of the liners, as such, but that the contractor, New Earth Solutions, was not keen to accept liners” that stopped them, “taking into account distribution, we worked it out as around £180,000 a year” – considerably cheaper than WRAP’s estimate.

The plant did eventually change its policy on liners, but by then the council had decided against a blanket drop. It did, however, distribute them door-to-door for free in hard-to-reach areas, which increased participation. Hopkins adds: “We’re now encouraging people to buy them. We are also making them available in customer service centres, libraries, that sort of thing, so if people do have a problem with financing them, you can get hold of them.”

Meanwhile, over in Wales, liners are more widely provided as part of the service. The City and County of Swansea has recently changed its food waste collection to weekly, with liners provide free of charge. Although Jason Rogers, Communications Officer at Swansea, could not provide details, he said: “Participation/capture rates have improved significantly, but it is difficult to say whether this is down to the fact the collection is now weekly or the fact liners are now being issued.”

Likewise, Monmouthshire County Council has no concrete data on participation or capture rates, but it is hoped that the four rolls of 26 caddy liners that have been provided to last a year (at 3p each, this is more in line with WRAP figures), will increase buy-in to the food waste scheme. However, Paul Quayle, Waste Strategy Officer at Monmouthshire County Council, says the decision to supply two liners per week to the 39,000 householders is currently under review. Whether the council can justify the cost without any evidence of what the liners have achieved remains to be seen.

Partner authorities in the WRAP trials offered the following consideration: “If additional diversion of food waste from disposal due to use of liners could be proved and quantified, the associated avoided disposal costs could justify the provision of free liners.”

Two and a half years on and further research into the use of liners and the effect on participation/capture rates is still very much needed. Although awareness of the food waste issue is improving, there are still those that don’t realise how much they are throwing away. Whether food waste liners are encouraging people that wouldn’t compost unless they were available is debateable, and councils vary on their opinion, but one thing is for sure: it’s a lot less messy.