The Consumer Product Safety Commission yesterday voted to seek penalties against three companies believed to have purposely distributed children's pajamas treated with Tris, a cancer-causing chemical, after they had been banned by the government.

The hazardous garments are among hundreds of thousands of Tris-treated children's pajamas believed to have reached retail stores in the last year or so -- in some cases apparently sneaked onto the shelves by companies that found the product to expensive to dispose of or hold.

"We're finding it in many places all of a sudden," said John Bell, a spokesman for the CPSC.

Tris is a fire retardent that has been found to be carcinogenic. It was widely used in children's sleepwear before it was banned in 1977.

The CPSC said it will seek fines of $500,000 each -- the maximum penalty allowable under its civil proceedings -- against Hollywood Needlecraft Inc. of Los Angeles, which the commission charges distributed the sleepwear that at some point was packaged in bags labeled "no Tris," and against John R. Lyman Co. Inc. of Chicopee, Mass. and S. Schwab Co. Inc. of Cumberland, Md.

"In all three cases they knew what they were doing," the complaint alleges, according to Bell. Most of the small pajamas were located and destroyed, he said, but the agency has no exact count of how many may be in use. The charge against Hollywood Needlecraft and Schwab is that they failed to report the distribution of the garments. The charge against Lyman is that the firm knowingly distributed a defective product.

Officials for Schwab and Hollywood Needlcraft said they had no comment on the CPSC's action. No official of the Lyman Co. could be reached for comment.

About 6.5 million Tris-treated garments still are being held by rag cutters or manufacturers. Another 2.5 million have been cut into industrial wiping clothes or destroyed, but some companies have complained about the cost of disposal.

Some of the Tris-treated garments have been exported.

According to the complaint, Hollywood Needlecraft, which manufactures children's sleepwear and clothing, sold Tris-treated garments to Ely Finer Co. Some of the garments were later sold to a Granada Hills department store.

The CPSC later determined that approximately 8,000 pounds of the children's pajamas and nightgowns -- or some 25,000 garments -- had been sold through the company's mill outlet. The company agreed to post repurchase and refund signs.

According to the complaint against Schwab, the children's clothing manufacturer sold Tris-treated garments to a Wichita, Kas. firm that was told by a company represenative that they could be sold. The buyer subsequently discovered this was untrue and contacted Schwab, which agreed that the garments should not be sold. They were not.

The CPSC has warned parents to buy no sleepwear from which either the manufacturer's or contents labels have been removed.