The kerosene heater, the subject of intense controversy for nearly a year, is generally safe when used properly. On the other hand, certain aspects of the heater can pose problems and suppliers need to take steps to upgrade the heaters to reduce the chance of injuries from burns and from unhealthy emissions.

That is the conclusion that the Consumer Product Safety Commission staff has reached after eight months of study and nearly $1 million of testing.

The staff will present its findings to the commission at a special hearing today. Industry officials will have an opportunity to present the results of their research after the CPSC staff finishes its report.

Commissioner Stuart M. Statler, who has read the 24-page report prepared by the staff, said it concludes that "kerosene heaters are safe, with certain caveats."

Questions about the heaters were propelled into the spotlight a year ago when Consumer Reports, in its October cover story, charged that kerosene heaters represent an unnecessary health hazard. Kero-Sun Inc., the company which began importing large numbers of kerosene heaters made in Japan, filed a lawsuit against the consumer group, charging libel. That suit has since been dropped.

Meantime, profits for Kero-Sun have tumbled and sales of kerosene heaters have fallen, in part because of the warm winter in the United States this past year and in part because of questions about the safety of the units.

David Pittle, director of product testing for the organization and a former CPSC commissioner, says the 1982 magazine report and the latest CPSC findings are not in conflict.

"The CPSC staff doesn't say that kerosene heaters are safe; they take the position that if you use the heater right that there is no hazard. That is true of almost every product hazard ever described. Lawnmowers, for instance, won't cut unless you stick your hand in them. So it is true that if you use the product right, you won't get hurt. The question is whether it will be used right. And that will depend on whether consumers in the middle of winter will open their windows and doors as the heater manufacturers recommend."

Pittle said that Consumers Union has reviewed its testing and concluded that its initial assertions in the magazine were "correct, fair and not misleading."

He expressed the hope that the commission will be able to achieve the goals recommended by the staff to improve heater safety. "If they can, it would be an important improvement in the safety of these products. But if the industry dallies, I hope the commission will move to require the improvements."

The kerosene heater testing was the CPSC's top priority this past year. At one point, eight researchers at the agency's laboratory in Gaithersburg were assigned to conduct the study.

In summarizing the results of those tests, the CPSC staff report said it was the staff's judgment that the "most important element of kerosene-heater safety is the pattern of consumer use."

No mandatory action is recommended at this time, the staff said. However, the staff did strongly encourage:

* The requirement of emergency shut-off devices to provide a means of extinguishing a flare-up at the wick.

* The incorporation of a wick stop to prevent wick adjustment to a position lower than the manufacturer's recommended setting. Such a device may prevent some types of flare-up and the higher emissions associated with maladjustment.

* A test requirement limiting the nitrogen-dioxide emission rate to reduce the potential for health effects.

* The addition of guards or grilles for hot kerosene heater surfaces to reduce the likelihood of and severity of contact burns, especially to children.

* An enhanced information and education effort to explain heater safety.

Other recommendations also were made by the staff to upgrade the voluntary provisions for tipover, carbon-monoxide emissions, label durability. In addition, the staff recommended that steps be taken to encourage greater distribution of certified 1-K kerosene fuel and the adoption of a uniform voluntary kerosene-container standard.

The staff said that the possibility of problems with kerosene heaters increases under several conditions, including the use of larger or wickless heaters or the use of any kerosene heater in a closed room.