A couple of years ago I met a nonplussed father whose eight-year-old daughter refused to allow him to eat mayonnaise because of the orangutans. As he was struggling to make the connection, I explained how orangutan habitats in Sumatra and Borneo were being clear-felled at an incredible rate for conversion to oil palm plantations.

I wonder if his now-10-year-old is on a permanent protest rota between the kitchen and the bathroom, refusing to let her poor dad chew gum, use shampoo or make toast. Because just as palm-oil monocultures have swept across Southeast Asia, charged with the catastrophic destruction of wildlife, forest habitats and pollution, the results are ubiquitous in our shopping basket. An investigation last year found that palm oil – often obliquely labelled as "vegetable oil" – was found in 40% of bestselling groceries.

If you attach more importance to the planet's biodiversity than the creaminess of a shampoo, go palm-oil free. Lush Cosmetics, acknowledging that the cosmetics industry uses 6-7% of the global supply of palm oil, decided to stop using it altogether.

But really, why should we be driven to niche non-palm-oil products when sustainable palm oil is readily available? Yes, palm oil can be and is being grown sustainably. The global initiative that aims to bring together processors, manufacturers and NGOs known, as the Roundtable on Sustainable Palm Oil (RSPO), had certified enough plantations to produce 1.75m tonnes of sustainable palm oil midway through this year. The tragedy is that less than 15% of this sustainable oil has actually been sold.

All of this is laid bare in the Palm Oil Buyers' Scorecard, recently published by the WWF. Sainsbury's, M&S and Unilever (which alone accounts for 6-8% of total world production of palm oil) are sitting relatively prettily in the top five. Morrisons, Waitrose, Nestlé and Boots appear in ugly positions much, much further down.

Brands often claim they source sustainably wherever possible. In this instance it is possible, yet the majority of the 59 companies investigated had elected not to use sustainable palm oil.

It is important that we put pressure on them to change immediately. As Sean Whyte of www.naturealert.org puts it: "Palm oil companies are grabbing what forests they can, while they can. Countless documentaries have shown thousands of hectares of bare land, where palm oil companies have bought licences to log forests and convert them to plantations."

And it will get worse. Output of crude palm oil (CPO) has increased 400% since 1990, and 89% of it comes from Malaysia and Indonesia. There is huge demand from bioenergy projects as well as for consumer goods – and according to the WWF, most of the remaining areas earmarked for plantation are forest.

There's no time for any more greasy excuses.★

lucy.siegle@observer.co.uk