Commission Approves Mandatory Standard To Improve Safety Of Unvented Gas Space Heaters

The U.S. Consumer Product Safety Commission has approved a mandatory standard to improve the safety of unvented gas-fired space heaters, which are associated with approximately 70 deaths every year due to carbon monoxide poisoning.

The safety regulation will require by mid-1981 that manufacturers equip these heaters with an "ODS" (oxygen depletion safety shut-off system) to inhibit the buildup of life-threatening levels of carbon monoxide. 1 An ODS functions by shutting off the heater's supply of gas when the oxygen level in the area has been reduced to 18 per cent (compared to the normal level of oxygen in air of 20.9 per cent).

The Commissioners, voting 3-to-2, approved the safety rule on the basis that existing technology is capable of applying ODS's to unvented heaters, and that a mandatory safety standard will encourage industry to equip each new heater with an ODS as soon as possible.

Commissioners David Pittle and Sam Zagoria, who voted in the minority, both approved the standard in principle. However, they voted to postpone consideration of whether to issue the rule until March, 1981. Both argued that the majority's decision was premature in light of the public commitment of both the American Gas Association and the American National Standards Institute (ANSI) to require the system on virtually the same timetable as the Commission's mandatory standard. *

The standard will require all unvented gas heaters which are manufactured or imported after June 14, 1981, to be equipped with an ODS. Because the usual production cycle for such heaters runs from early each year only through June, the standard will have its initial effect on heaters manufactured for the 1982-83 heating season.

Unvented gas-fired space heaters are among the least expensive heating appliances on the market today, according to CPSC staff. A medium-sized heater currently costs a consumer approximately $170 to $180, can be operated at lower costs than vented gas-fired heaters and has very high thermal efficiency.

Many of the people who purchase these heaters are elderly or from low-income groups and reside in rural areas in southeastern and south-central states where the mild climate makes central heating systems uneconomical.

In addition, the Commission unanimously voted to propose an anti-stockpiling rule which will prohibit excessive production of unvented heaters unequipped with ODS's before the standard takes effect. When issued in final form, the rule will limit next year's production of non-ODS heaters to slightly more than the approximately 120,000 heaters manufactured annually in.1979 and in 1980.

Carbon Monoxide Hazard

Unvented gas-fired space heaters do not incorporate any venting system to remove carbon monoxide and other by-products of combustion from the immediate area being heated. Instead, the heaters discharge these combustion wastes directly into the living area. If adequate ventilation (such as through an open window) is not provided during use, life-threatening levels of carbon monoxide can begin to build as the oxygen concentration in the area becomes depleted.

Carbon monoxide depletes essential oxygen levels in the blood- stream, which can damage body tissues and result in death. Because carbon monoxide is colorless and odorless, most victims -- people of all ages -- were never aware they were being poisoned and many of them died while asleep.

To alert consumers to the potential effects of carbon monoxide, the safety standard will require that the heaters carry a warning label. This label will advise consumers of the need for adequate ventilation during heater use. It will describe the function of the ODS, and list the early symptoms of carbon monoxide poisoning.

CPSC staff estimates that a required ODS will add from $5.00 to $17.50 to the retail price of the unvented heaters.

The Commission in 1978 proposed to ban unvented gas space heaters, believing that no safety standard could be developed to reduce adequately the associated carbon monoxide poisonings. However, information gathered during the traditional period for public comment indicated that devices similar to the ODS had been used successfully for years in Europe on unvented heaters. CPSC also learned that a voluntary standard (published by ANSI) provided for optional use of an ODS on American-manufactured unvented gas space heaters, although ODS's have not been applied to U.S. heaters.

The safety standard is drawn largely from the ANSI voluntary standard. Its development has had the effect of inducing American manufacturers to develop the technical expertise to manufacture the ODS and to equip U.S. unvented heaters with the safety system.

* Additionally, both noted that if the industry faltered in its commitment, the Commission next March still could promulgate its mandatory standard in time to affect the heater production for 1982. Commissioners Pittle and Zagoria also were concerned that a federal mandatory standard would preempt state and local regulations in many areas of the nation that ban unvented heaters; they argued that this could adversely affect consumer safety.