Trying to be a good consumer, Steve Goldstein, 32, signed the Exxon credit charge for his gasoline purchase from the Arlington station and pulled the carbon paper from the form, along with his paper copy of the transaction.

"That is what we all have been advised to do to prevent credit card fraud," said Goldstein, a member of the staff of U.S. Rep. Manuel Lujan (R-N.M.).

But as Goldstein quickly learned, it generally isn't possible to take that precaution when using a gasoline credit card.

"The attendant asked to have the carbon paper back; he said it was the station's only copy of the transaction," Goldstein said. "He said that the paper copy was mine, that the hard copy went to Exxon and that the carbon paper was the only thing left for the station."

Exxon officials say this is a common industry practice throughout the country, despite questions from anxious consumers.

"This comes up about once a month," said Bleu Beathard, an Exxon representative familiar with the matter. "What originated the concern is that MasterCard and Visa and others like that usually have charge forms with three copies: one for the customer, one for the charge company and one for the merchant. They also have two pieces of carbon paper that get thrown away. But some of the carbon papers were retrieved by crooks who used them to make counterfeit cards or to make illegal telephone purchases. To counter that, Visa and the others started an educational campaign telling everyone to destroy the carbons."

Gasoline companies, however, use a different kind of charge slip with two parts instead of three, Beathard said, which makes it difficult for consumers who want the carbon papers.

Beathard gave this explanation: "Our carbon paper isn't just to make a copy. We have two paper copies and one carbon paper. We use the carbon paper as a third copy. The customer gets one copy and the company gets one copy. The dealer keeps the carbon paper as his copy and treats it the same way that a merchant treats his paper copy."

Beathard said the gasoline industry system of retaining the carbon paper is as safe for consumers as the bank and entertainment card system of giving them to consumers to keep or destroy.

"People have come to think the carbon paper is more of a security risk than the carbon copy," he said. "But it isn't, because the station uses the carbon paper like a regular piece of paper. If we did have a three-part form, so that we gave the dealer a paper copy, then there would be two carbons that would be a security problem and these carbons would have to be destroyed or given to the customer to destroy.

"So we think our system is as secure as the three-part form if not more so."

Goldstein isn't so sure. "I understand the point they make. But from all the warnings that have been issued, I would feel more secure if I got to keep my carbons."

The credit card industry, meantime, has been working to come up with ways to reduce the risk of fraud. One possibility is to use carbonless charge slips. Another would be to use perforated carbon paper that can easily be torn in half, with some of the credit card numbers on one half and the rest on the other.

In addition, some companies, after receiving a phone order for merchandise, will confirm the order by calling the card holder or sending a letter describing the transaction -- just to make sure that the person who gets the bill for the order is the person who placed it.