It contains palm oil. And buying an eco-brand doesn't help. Many of them have it, too.

The world of suds is quite the soap opera. Trying to sort it out took me into global commerce, biodiesel, and vegetarianism.

One thing I learned: Industry loves palm oil.

Foodwise, it's a cheap substitute for fats. According to the American Palm Oil Council, 90 percent of palm oil is used in foods even though experts say it promotes heart disease.

The other 10 percent is used in soaps, plastics, candles, and skin-care products. And in biodiesel, to replace vanishing petroleum. Palm oil, on the other hand, is expandable. Need more? Plant it.

But that's the problem. Palm oil plantations are the leading cause of rain-forest destruction in Malaysia and Indonesia, says the U.N. Environment Programme.

In the last 20 years, one quarter of Indonesia's forests have disappeared. Cutting the trees for timber releases the carbon they've stored; setting fires to clear peat lands releases even more pollutants into the air.

In terms of greenhouse gas emissions, Indonesia is No. 3 behind the United States and China, says Rolf Skar, senior forest campaigner for Greenpeace. "Palm oil is the driver."

Plus, indigenous peoples are displaced. The critically endangered Sumatran orangutan has lost its home.

The industry says it is coming up with sustainably produced palm oil. But can a consumer make a difference?

After an hour at the grocery store squinting at labels, I decided there was hope.

I was looking for palm oil, palm kernel oil, variations like "fractionated palm oil," and Elaeis guineensis, the species name of the tree.

Most foods with palm oil are easy to avoid. I found it in popcorn, crackers, cookies, canned mac and cheese, frozen french fries, cookie doughs, even some cereal.

As usual, stick to fresh fruits and veggies and you're OK.

Soap was where things got weird. Almost every brand included palm oil. Or possibly did. Because feedstocks can vary, some listed palm oil as one of several possibilities.

Since the beginning of modern hygiene, soap has been made with animal fats. A lot of the nation's first soap companies were in Chicago, near the slaughterhouses.

How does slathering yourself with pig lard or cattle tallow get you clean? Mix it with a strong alkali, and the resulting reaction, saponification, produces a chemical salt (the soap) and glycerine.

Palm oil is an often-used replacement for animal fats because it has many of the same properties, and it's cheap as heck.

We'll probably see more of it, too. It turns out that national policies are steering animal fats into biodiesel production, so the price is rising. In the soap world, "the substitute commodity will be palm oil," said Dennis Griesing, vice president of the Soap and Detergent Association.

Checking the soaps in a health-food store, I found their wrappers list many virtues:

Tom's of Maine soap has no artificial fragrances, colors, preservatives, or synthetics.

Plantlife soap - "For People and Planet" - is "pure and natural" and vegan.

Dr. Bronner's Magic Soaps bars are "certified fair trade."

But all have palm oil. Although it's clearly a consequence of avoiding animal products, I doubt orangutans would appreciate the logic.

At least one company has drawn a line in the forest.

Wesley Burridge is the product formulator for Lush Cosmetics, and has spent the last several years in his Poole, England, lab working out a soap formula that contains neither animal fat nor palm oil.

The chemistry was difficult enough - all oils are different. Price was another hurdle. Almond oil, for instance, costs twice as much as palm.

Eventually, he succeeded in removing all but a smidgen of palm oil. Last month Lush debuted its new line, sold "bare" (unwrapped).

I tried the "Honey I washed the kids" soap. It looked like fudge and didn't suds much, but I got clean.

At its Walnut Street store, employees set up a window display with a palm tree, an orangutan, and the slogan "Wash your hands of palm."

Lush has written to the top 300 companies that use palm oil, offering a year's worth of its soap if they change their own products.

So far, no takers.