An estimated 40 percent of the half million refuse bins - the large garbage containers frequently found in apartment house parking lots - under federal regulatory jurisdiction are dangerously unstable, in violation of federal safety regulations, and responsible for the death of 21 children since 1971, according to the federal government.

And despite the fact that the Consumer Product Safety Commission banned unstable bins in June 1977, since that ban, three children hanging or swinging from unsafe bins were killed when the bins toppled over and pinned them to the ground.

"We want to get children away from these death traps," said CPSC commissioner Edith Barksdale Sloan at a press conference at a Washington, D.C., refuse company. "We only have about 40 percent compliance - most of the companies involved have been very slow to do anything.%

Sloan showed the stabilizer legs needed to make the unsafe refuse bins - or dumpsters, as they are are sometimes known - safe. "It cost any-where from $25 to $75 to fix these bins," she said, "and we are now sending our compliance staff out to see if we can get more cooperation, or we will consider legal action."

Sloan said the commission might ask for a court injuction to force firms to remove the dangerous bins until they are rendered safe.

The District was one of the first local governments to ban the use of unstable refuse bin on its own in 1976. Since the D.C. ban, no deaths have been reported here.

"About 60 percent of the city's refuse bins have already been corrected," said Dr. Bailus Walker, director of the Environmental Health Administration in D.C. "We will survey targeted areas of the city to determine if the remaining number of unstable bins have been stabilized. We will take action against violators."

Walker said local wast-haulers will be notified of the location of the illegal bins and if they are not stabilized, the waste-haulers in question will be subject to court action and a fine of $50 to $300 for each violation.