After nearly 10 years of questions and 2 1/2 years of debate, the Consumer Product Safety Commission is nearing a final decision on whether to require safety hinges on toy chests. The critical moment comes Wednesday, when commissioners are to vote on a final standard that would require the use of safety hinges.

Six months ago the CPSC voted to draft a standard that would require toy chest manufacturers to equip them with hinges that would stop at any point in the opening arc. The vote came after the commissioners lashed out at the manufacturers for failing to do something voluntarily about the lids, which have been linked to the deaths of 21 children since 1973.

But, in a study presented to the commission last week, the staff estimated that 86 to 89 percent of the toy chests now produced for sale are equipped with safety hinges. In addition, industry officials say they are considering a voluntary standard that would increase the number of toy chests with safety lid supports.

However, Commissioner Edith Barksdale Sloan said that manufacturers may have waited too long to comply voluntarily.

"We have a question of good faith," she said. "Are we to assume an industry that has stood by for 10 years will see the light now? I find that a little hard to believe."

If approved by the commission, the rule could take effect within 30 days after it is published in the Federal Register.

Of the estimated 700,000 toy chests manufactured annually by about 30 U.S. companies, about half have hinged lids that would require the addition of a lid support under both the mandatory and voluntary standard proposals. Most of the toy chests range from $18 to $85 at retail stores.

According to information obtained by the CPSC staff from industry sources, the required hinge could cost the manufacturer as little as 10 cents. The maximum cost to the manufacturer would be $1.77, the staff said. MESH PLAYPENS . . . The CPSC yesterday urged the nine U.S. manufacturers of mesh-sided playpens and cribs to do more to educate consumers about the potential suffocation hazards of their products.

"The situation we are facing is serious," Chairman Nancy Harvey Steorts told the company officials. "This can cause a serious problem for parents because they do not know about it."

At least 11 infants have died since 1973--three of them last year--after they were left in mesh-sided playpens and cribs with one of the two drop sides down. Manufacturers have been placing warning labels on new mesh-sided cribs since 1980, and they have told the CPSC that they will add the warnings on new playpens. But the agency is worried about the estimated 6.5 million playpens and 1 million cribs already in the hands of consumers who may be unaware of the hazard.

"You've got millions of these playpens out there in storage in attics and garages," Commissioner Sam Zagoria said. "The question has to be, 'What's being done to bring this to the attention of future users?' "

Industry officials said that the Juvenile Products Manufacturers Association has started a two-year public awareness program aimed at those who already own the playpens. The program includes sending posters to hospitals with maternity wards, parenting classes and the nation's 53,000 pediatricians. NEW VOICE FOR THE CPSC . . . Barbara Coleman, the agency's new $56,643-a-year director of public affairs, has started to design special consumer education programs to carry out the agency's priorities for 1984. "We want to get the word out from the national level to the grass roots," she said.

Priorities so far include gas heating systems, indoor air quality, chlorocarbons, fire toxicity, electrocution hazards, nursery equipment and riding mowers. More may be added later.

Coleman also is working on an information program on smoke detectors. If she gets the commission's approval, she wants to launch a media blitz of public service ads and announcements and appearances by commission officials. "Then we want to develop and print consumer literature containing advice for people to use," she said.