Slow burns come easily these days for William Kloepfer Jr. He is a vice president of the Tobacco Institute, the lobbying and communication arm of the $23 billion industry whose factories last year produced 640 billion cigarettes. About those products, Kloepfer is a health agnostic: he professes not to know if cigarettes are dangerous.

It's the sure believers who rankle him most, people he calls "propagandists." In his office one afternoon, he is asked: Any names? He lights a cigarette--he is a confident agnostic--and says sure: Michael Pertschuk of the Federal Trade Commission and Stuart Statler of the Consumer Product Safety Commission. Kloepfer asserts that both "have made it clear that they would rather the American people not smoke cigarettes. They propagandize against cigarettes."

Pertschuk and Statler upset Kloepfer and his aggressive institute because both are among the leaders of a push to decrease the health and safety hazards of cigarette smoking, the nation's most widespread addiction.

Pertschuk testified earlier this month before the House subcommittee on health and the environment in favor of legislation that would, among other things, require stronger warning labels on packages and ads about the potential health threats caused by smoking. Statler, before the same subcommittee 12 days later, backed the Cigarette Safety Act, a bill that would empower the Consumer Product Safety Commission to develop standards to reduce the long burn of cigarettes. Fires started by cigarettes in 1981 killed more than 2,100 people and injured more than 9,500.

Kloepfer's charges of propaganda are wisps of stale smoke. The statements of both commissioners, as well as the arguments of the bill's main sponsors--Rep. Henry Waxman (D-Calif.) and Rep. Joe Moakley (D-Mass.)--are compilations of careful research. It is not propaganda to say that much more can be reasonably done to reduce the immense amount of death and suffering caused by cigarettes. It's justified concern.

The public has two teachers on smoking: the industry and public health officials. In the faculty smoking room at the Tobacco Institute, the favorite word is may: cigarettes may be harmful to health. If they were teaching grammar school geography, they would point to the globe and announce, "Students, the Earth may be round."

The institute's second favorite word is will, as in its statements of certitude before the subcommittee on the Waxman bill: "The regulatory philosophy embodied in this legislation, if it is allowed to continue, will be used against other industries--food, beer, wine, alcohol. . . . The anti- business spirit that inspires this bill convinces (us) that the hit-list will expand. Today, tobacco --tomorrow, who knows."

This domestic domino theory is a sham threat because in fact cigarettes, except for taxation and crop subsidy, are exempt from federal regulations. Other consumer products, much less dangerous, are currently regulated--or have been banned-- without apocalyptic results.

The legislation proposes that all cigarette packs or ads carry one of three messages, randomly applied. Two would be brief statements about the benefits of quitting and the effects of smoking on pregnant women. The third strengthens the current wording: "Warning-- Smoking causes lung cancer and emphysema, is a major cause of heart disease, is addictive and may result in death."

The warning labels are no more than basic information. In the ads, the Marlboro man will still be atop his horse, not in the cancer ward. According to Pertschuk, the FTC has found that "millions of potential smokers, including our young people, and millions more smokers, do not comprehend the full nature and extent and the risks of smoking. Nearly 20 percent of the population, and 28 percent of smokers, still don't believe smoking causes lung cancer. Thirty-two percent still don't know smoking causes heart disease."

The labeling fight is an old one. The industry has lost twice, when Congress imposed warnings in 1965 and revisions in 1970. Creating a shorter- smoldering cigarette is a new battle. The institute, with a thick smoke screen the first time out, claims it can't be done. Statler and Moakley have doubts about that. They ask fair-mindedly that CPSC be given two years to see if a less fire- causing cigarette can be developed and lives be saved. If not, the matter is closed.

The industry would close it now, as well as halt the move for stronger label warnings. Its arguments are as firm as ashes.