The biotechnology industry needs to find other uses for its GM crops - uses which it hopes won't upset the public. Billions of dollars have been invested in developing crops, and intellectual property rights have been put in place that should allow the profits to roll in, but the resistance of people in Europe and many other parts of the world has upset the industrial dream of a GM future.

Prime targets for GM are the so-called "non-food" uses: grasses, flowers, trees, cotton, and a range of different crops being modified to provide the raw materials for the industrial production of biofuels, oils, starches and plastics.

So, if you don't have to eat them, are there any real reasons to worry? In a word, plenty. Non-food uses are likely to bring in contamination of non-GM crops and nature by the back door. This much is clear if you consider what may be on the market soon.

Perhaps the most alarming development is GM herbicide-tolerant amenity grasses. Particularly in the US, there is a search for the perfect lawn - one which is low-maintenance, weed-free, uniform and that can survive stressful environments, such as prolonged periods of drought.   Monsanto, in partnership with Scotts, a lawn and garden products company, is seeking to commercialise a GM herbicide tolerant creeping bent grass in the US. The original application was withdrawn, but a decision on a new application, filed in 2003, is expected shortly. Experimental GM golf courses have already been planted.

The problem is that grasses are difficult to contain. They are freely wind-pollinating, perennial and often reproduce via underground shoots. Grasses spread internationally on wool, and in lawn and bird seed mixes, so attempts to isolate GM grasses will probably prove futile over time. Golf courses and gardens are often close to natural habitats and farmland.

No one, it seems, has considered the international implications of this development. Britain has worried about GM forage grasses for animals, but not amenity grasses. GM herbicide-tolerant grasses could pose weed problems for farmers and lawn-keepers alike, as well as having a very real potential to establish themselves as an alien invader.

Trees, while less advanced commercially, pose similar kinds of problems in terms of international contamination, and herbicide tolerance is another favourite of GM tree producers. It makes economic sense for the owners of the genes to use them as widely as possible, which is why Monsanto also has a toe in the GM tree water.

But there are also more familiar GM crops looking for a new role in life. The interest in biofuels to replace fossil fuels has led to the suggestion that GM herbicide-tolerant oilseed rape and sugar beet could both be used improve production efficiency. This would open a new market for crops that have been rejected for food use. However, the contamination threat to non-GM food crops will be very real, especially with oilseed rape. And both oilseed rape and sugar beet have wild relatives in Britain with which they can hybridise.

Rather unsuccessful attempts have been made to turn oilseed rape and other oil crops into producers of specialist oils and plastics for industrial uses. The idea is that a particular oil produced by plants such as jojoba and coriander could be produced more efficiently in a domesticated crop. However, problems have arisen because producing the fatty acids that make up oil is much more complex than was once thought.

Fatty acids have at least three roles in plants - as a constituent of membranes, in cell signalling, and for energy storage. Unfortunately these are not controlled by separate pathways, and when novel fatty acid synthesis has been induced by GM it has not been possible to restrict the presence of the acid to the seed storage sites. There has, for example, been leakage, with the new fatty acid being found in cell membranes, where it can be destabilising and can adversely affect their function.

Another approach could be to make efforts to improve agronomic performance of plants like jojoba or evening primrose, but this is patentable and so is not a profitable avenue for the biotech industry to explore.  <P>Producing plastics has been similarly problematic, with adverse effects on growth being common. All GM approaches are dogged by yields that   are not economically viable. And the prospect of having industrial oils and plastics in your food as a result of contamination is not appetising.

One notable success in non-food uses has been GM potatoes, with altered starch production. Amylogene, owned by BASF, has produced potatoes high in amylopectin starch, which is more useful to the paper industry than amylose starch.

These GM potatoes are in their final stages of approval in Europe. They are unlikely to be grown in Britain, but could be in eastern Europe, the Nordic countries, Germany, the Netherlands, Belgium and France, all of which grow potatoes for starch production. These are unlikely to pose contamination threats via pollen, but there will need to be systems in place to maintain their separation from the human food chain, as the residue after starch extraction is intended for animal feed.

It is the apparent success of GM cotton, however, that encourages the application of GM to non-food uses. It has attracted little consumer interest and is grown internationally on many millions of hectares. GM insect-resistant cotton has reduced the use of some insecticides in a system which is highly intensive and environmentally damaging. However, the selling of GM cotton as a cure for the ills of pesticide use is eerily familiar to the way in which the pesticides themselves have been sold.

Short-term benefits and high-cost inputs are being promoted by industry salesmen. Loans for seed purchase and second-generation GM crops, if the first-generation cotton fails, are already part of the plan.

Developing countries are the targets for expansion of the GM cotton market in Africa, south-east Asia and South America. So while the prospect of GM food crops being grown in Britain has receded in the short term, the industry has a whole new rationale and a raft of new uses for the technology up its sleeve.

With some of these, such as GM grasses, there will be little comfort that it is happening elsewhere. Inevitable, accidental international movement means they will surely find their way to Britain.

Sue Mayer is director of GeneWatch UK, which monitors developments in genetics technologies. More information: www.genewatch.org