Despite the fact that federal agencies are taking major steps toward regulating toxic substances and keeping them from the maketpalce, private industry must play a major role in the eventual control of the dangerours hazards, according to a federal safety official.

R. David Pittle, a member of the Consumer Product Safety Commission told an Envoronmental Defense fund Toxic Chemicals seminar in New York this week that regulation toxic substances already in the market "is a job that will take the combined resources of all the government regulatory agencies and the industry, as well as the Environmental Defense Fund."

Pittle, who will likely become chairman of the CPSC when its present chairman, S. John Byington, leaves at the end of June, said he hoped industry will cooperate with government regulatory efforts. "Where it cannot," he warned, "the government must be ready, willing and able to intervene."

Pittle outlined the recent announcement by his agency that it plans to aggresively seek out and ban cancer- causing agents presently in consumer products.

He said the principles recently adopted by the commission "embody the need for ridding the environment of toxic substances while recognizing that the risks from the substances must be balance against the benefits they bring - but with the scales weighted heavily on the side of caution."

Pittle said that unsafe substances should be phased out and replaced by safer ones, but added, "Where no safe substitutes exist, the social and economic costs of banning the results, the substance either will be banned . . . or reduced to the lowest level attainable."

Despite a strong commitment by the government to the regulation of the production, distributing and use of toxic substances, Pittle acknowledged that "mandatory government regulation is an increasing unpopular subject these days."

"Business people and consumers generally are feeling threatened by what they perceive to be increased governmental control over their lives," he added.

Pittle cited examples of consumer unwillingness to heed government warnings. "Many people , he said, "simply refuse to believe in the connection between Saccharin consumption and cancer because, after all, they have neither seen or heard fo anyone getting ill or dying from drinking diet soda."

Pittle called for industry to work with the government to "see that dangerous chemicals are removed from the marketplace as soon as they are discovered, without the need to await government intervention."