Peter Robinson, director of the environmental charity Waste Watch, answers your questions.

I am a campaigner for Plastic Bag-Free Godalming. Can you clear up the definitions of degradable and biodegradable? My understanding is that degradable is not compostable – ie, those bags break down into tiny pieces of plastic that will remain in the environment whereas biodegradable (as in BioBags) can compost and break down completely with no harmful effects to the environment.
Ruth Bolton, Godalming, Surrey
- Absolutely right; the only advantage of degradable bags is they pose less of a litter nuisance once they break down. Biodegradable plastic bags are only better for the environment if they are properly composted – something that isn't widely happening at the moment. As a rule, I take cotton bags on my shopping trips rather than accept free plastic bags. Every couple of months I leave the cotton bags at home and take the plastic bags, which I then use as free bin bags.

Is it better to use the plastic bags as bin bags, or is there a more environmentally sound way of dealing with rubbish?
Catherine Richmond, Haverfordwest, Pembrokeshire
- Reusing bags over and over is of course the most environmentally friendly option and the fact that you do that most of the time is the most important thing. You also need to contain your residual waste somehow and I really don't think it makes a lot of difference if you reuse carrier bags or buy suitable bin liners. But do look out for those with recycled content and don't use bigger or thicker bin liners than you reasonably need.

Where can I buy small black bin bags? I throw out so little that three-quarters of a standard bin bag is waste plastic, but I can't store what little waste I do throw out until the bag is full, because of smells.
Mary Harris, London
- Maybe smaller pedal-bin liners are what you need? However, some local councils now collect food waste separately which might be an answer to the odour problem. Alternatively, if you can compost your biodegradable waste like vegetable peelings, tea bags and egg shells, you can deal with most of the materials that cause smells in way that's very good for the environment.

I work for a small children's clothes company. We use good quality polythene bags costing 4p each. I would like to change these to biodegradable bags or paper carrier bags. Can you suggest a source for them at a reasonable cost? Also, which of these is actually least harmful, bearing in mind the use of wood for paper versus land clearance for vast fields of corn for cornstarch?
Jane Jones, Knutsford, Cheshire
- With regard to which bags are least harmful, you need to think about what happens to the bag after you give it to the customer as well as how it's sourced. See my earlier comments regarding biodegradable bags, but also paper bags need to be recycled in order to avoid causing potentially more damage than the plastic alternatives. For information about suppliers you could try www.wrap.org.uk.

I was completely fed up with the number of plastic bags foisted on me, particularly as an internet shopper. So, together with a friend, I decided to take action. That was when we found it – a really clever type of shopping bag. The bags clip inside supermarket trolleys, helping to organise shopping and speed up checkout time. And so Geccobags.co.uk was born: a company specialising in utilitarian bags designed specifically for the supermarket.
Georgina Tuson-Little (www.geccobags.co.uk)
- There is a huge range of alternatives to disposable carrier bags, from organic fair trade cotton to supermarket's own Bags for Life.

Thank you for your timely piece on the curse of the plastic bag. I am old enough to remember when supermarkets charged for carrier bags. I cannot believe they are so reluctant to reintroduce the charge.
Roger Nobbs, London
- I can also (just) remember those days! The truth is there's no such thing as a free carrier bag; nowadays we just pay for them in the cost of the goods. That is really unfair to consumers trying to reduce carrier bag use – they are subsidising others who are more wasteful.

The story so far ...

British shops hand out more than one billion plastic bags every month, at a huge cost to the environment. Following the example of Modbury in Devon, which, earlier this year, became the first UK town to outlaw plastic bags, 80 towns and cities have introduced or are considering a plastic bag ban. Now 33 London councils have voted in favour of banning all shops in the capital from handing out free plastic bags. In two weeks' time, Westminster council will present a private Bill to the House of Commons to that effect.

(The Independent, 15/11/2007)