Nor does he believe the problem could lie in mislabeling: Over-the-counter dietary supplements are required by law to list each ingredient on the label, Seckman said, adding that the chances of them being contaminated are “infinitesimal.”

However, Tommasello cited a German study found almost 15 percent of 634 supplements tested from 13 countries (including the United States) and 215 suppliers contained steroids not listed on the label.

Palmeiro was the seventh player to fall under baseball’s new, tougher steroids policy; Seattle Mariners right-hander Ryan Franklin became the eighth when he was also suspended 10 days for a violation Tuesday. Baseball does not release what type of drug a player has tested positive for, and so far none of the eight have spoken openly about details of their violations.

Fellow players were mixed on the credibility of Palmeiro’s claims.

“It’s a shame,” said Atlanta Braves outfielder Brian Jordan. “He’s been in front of Congress. It’s another shock to the game of baseball. ... He’s accomplished some great things and now he’s going to have to answer some serious questions.”

Chicago White Sox catcher A.J. Pierzynski expressed sympathy for Palmeiro, who last month joined Hank Aaron, Willie Mays and Eddie Murray as the only players with 3,000 hits and 500 homers.

“He could have been taking a supplement over the counter. Sometimes things get mixed up,” Pierzynski said. “That’s one thing the union has really tried to address with us, is that you don’t know what’s in supplements. You have to be real careful.”

Manufacturers are responsible for ensuring the safety of dietary supplements, but generally do not need FDA approval to produce or sell them. Tommasello said that lack of regulation should raise concerns — especially considering problems with regulated drugs such Vioxx, a painkiller later found to be linked to increased risk of heart attack, which are well studied.

“We know pretty much what drugs are going to do to people, what the side effects are and the risk and even at that, we have problems,” Tommasello said. “I don’t think we know clearly what these chemicals (supplements) are doing to people.”

Baltimore Ravens coach Brian Billick called the issue his “biggest concern.”

Slide show: The Week in Sports Pictures   Oct. 3 - 9 Images from the baseball playoffs, NFL, college football, and more.

“The combination of this and that, what’s actually in it, you’re trying to do the right thing, you’re trying to take legal supplements to take care of your body and it is so unregulated,” Billick said. “That is a major concern of mine, but that’s a societal concern, not just a football concern.”

Because of the confusion, the National Football League and its players union announced a program two years ago to certify supplements as free of banned substances and Major League Baseball is also looking into a similar program.

Tommasello, however, said his experience in drug testing has shown him that it is not an easy task. “People say they got a false positive (for opiates) because they ate poppy seeds,” he said, noting such claims were at first dismissed, then found to sometimes be true after further testing.

Washington Nationals outfielder Brad Wilkerson, who has said he used creatine and protein powders in the past, isn’t taking any chances in baseball’s current climate.

“A lot of guys have limited what they’re taking,” Wilkerson said Tuesday. “I really don’t take anything anymore. I really don’t know what’s in what.”