In response to Nic Boatman (Gazette, 18 April) the green sacks used to collect recycling in Hackney are made from 90% recycled material and are recycled after collection. We have included this in information provided to residents and apologise to Mr Boatman if he has not previously been made aware. Green sacks were chosen to replace the old green boxes as they have a greater capacity and can be used in 14,000 more homes in Hackney where residents did not have space to store the boxes. Trials in Cazenove ward showed that 64% of residents preferred the system and that they could help to boost a recycling rate that has plateaued in the borough by making the scheme easier to use. Previously the council had to supply around 600 new and replacement green boxes each month which itself was very carbon intensive. A full modelling of the new system suggested switching to the green sacks would actually produce a carbon saving of 15%. We would recommend though, that residents avoid using new plastic bags each time they shop and instead use reusable bags, we even provide these free of charge at council events. Plastic carrier bags can be recycled, many supermarkets collect them and they can be placed in green sacks, although other items should not be placed inside them as this can prevent us from being able to remove contaminated items from recyclable materials.