On March 7, 2018, the House passed H.R. 1917, a bill that would delay for three years the implementation of more stringent emission standards for new residential wood heaters. The emission standards were promulgated by the U.S. Environmental Protection Agency (EPA) in 2015, and are becoming effective through a two-step process. Step 1 standards took effect on May 15, 2015; unless delayed, more stringent Step 2 standards will become effective on May 15, 2020. EPA's action revises standards for wood stoves and pellet stoves that were set in 1988, and establishes standards for other types of wood heaters, principally forced air furnaces and hydronic heaters, for the first time. According to EPA, smoke from wood heaters and fireplaces contributes "hundreds of thousands of tons" of fine particles to the air each year, nationally accounting for nearly 25% of all area source air toxics cancer risks and 15% of non-cancer respiratory effects. In many areas, in wintertime, wood heaters are the largest source of particulate air pollution. Until the implementation of this rule, however, many heater types were not subject to any federal emission standard. The rule will only gradually reduce this pollution, because it only applies to new heaters (not those already in use) and it gives the industry a five-year grace period (until 2020) before its most stringent (Step 2) standards take effect. Nevertheless, EPA estimated that implementing the rule will eliminate 360 to 810 premature deaths annually in the 2015-2020 period as well as reduce hospital admissions and lost work days due to respiratory illness. EPA quantified these benefits at $3.4 billion to $7.6 billion per year during the 2015-2020 period, more than 70 times the agency's estimated annualized compliance cost to manufacturers, $46 million. Trade associations representing the affected industries and affected companies have mixed views of the 2015 standards. While generally supporting revision of the 1988 standards and the inclusion of additional heater types, some have expressed concern that the standards will impose too great a cost. Homeowners may continue to use current, highly polluting equipment, rather than buy more expensive replacements. In its analysis of the final rule, EPA estimated the vast majority of cost (88%) would be borne by the hydronic heater and forced air furnace segments of the industry. Specifically, EPA estimated compliance costs for hydronic heaters and forced-air furnaces will be about 17% of total sales revenues for the two product types. EPA did not estimate the effect of these costs on prices or output, but the agency's analysis does conclude that high unit compliance costs could lead to "potential nontrivial increases in market price to wood-burning appliance consumers and potential decreases in output." In addition to cost issues, many commenters on the proposed rule expressed concerns regarding the process to be used in certifying compliance and the short period of time in which units available at the time of the rule's promulgation could be tested and certified. EPA addressed many of these comments in the final rule, making changes intended to ease the burden of certifying compliance. Industry representatives continue to express concern that there will not be enough time to develop new models, certify compliance, and meet lead-time requirements of product retailers for the Step 2 (2020) compliance deadline. This report presents some of the most frequent questions raised concerning the rule, so as to provide basic background information about the final wood heater rule, its potential impacts, and stakeholder reactions to it. [ABSTRACT FROM AUTHOR]