The Consumer Product Safety Commission agreed yesterday to continue to allow the sale of the controversial reversible caps for prescription pill bottles.

On a tie vote, the commission turned down a staff proposal to ban these tops on the grounds there was insufficient data to justify such a drastic step.

Attached one way, these caps are almost impossible for children to remove; if reversed, however, the tops become easy to open, especially for the elderly and handicapped, who have long complained about being unable to use childproof tops mandated by Congress and the commission.

The CPSC staff urged the commission to ban reversible caps -- which have been in existence for four years -- because the staff said their use would lead to an increase in poisonings and deaths among infants.

Although the staff acknowledged it did not have enough injury data to back up its position, it argued action was needed now, "rather than waiting to assemble the tragic statistics of childhood poisonings and deaths."

Two commissioners agreed with that position -- R. David Pittle and Edith Barksdale Sloan. Although these caps now account for only 10 percent of the market, the two commissioners argued that if the commission did not move to ban them now, they quickly would assume a larger share of the prescription bottle sales and thereby increase the likelihood of poisonings.

However, commissioners Stuart M. Statler and Sam Zagoria said the ban was premature. Zagoria also argued the reversible caps may be better than the plain childproof caps because many adults, frustrated with their inability to get the caps off, leave tops off entirely, making them more dangerous to children than bottles that have nonchildproof caps.