A $4.1 billion fund to finance the cleanup of toxic waste dumps and to compensate their victims won approval from the Senate Environment Committee yesterday, but major hurdles still face the measure on its way to becoming law.

The "superfund" is the centerpiece of the Carter administration's effort to deal with the public fears, lawsuits and buck-passing that have followed every dump site discovered so far. Conceived amid reverberations from the Love Canal toxic waste controversy in New York and moved along over opposition from the chemical industry, the superfund now shows signs of making it through Congress this session.

Yesterday's committee vote was 10 to 1, with Sen. Alan K. Simpson (R-Wyo.) the lone dissenter, objecting to the fund's size and scope. "It preempts state common law," he said. "It gives me the creeps."

The Environmental Protection Agency was "delighted" with the product, according to Administrator Douglas Costle, who said it was "very close" to President Carter's proposal. EPA's waste management administrator, Eckhardt C. Beck, said the bill made him feel "like a race horse waiting to take the bit."

A $1.2 billion version had passed the Commerce and the Ways and Means committees in the House. The Senate approach is much more comprehensive, providing compensation for out-of-pocket medical expenses as well as cleanup and applying to spills of hazardous materials like pesticides that cannot be called wastes.

The Senate committee also rushed in where the House feared to tread and made toxic chemical producers strictly liable for damages to citizens or their crops. By changing the required standards of proof, the provisions would make it easier for citizens to sue and for the fund to recover from the producers any money spent in the cleanup. The House Commerce Committee killed any third-party damage claim language.

The Senate committee approach goes so much further than the pending House package, in fact, that the Chemical Manufacturers Association expects a sort of silent majority to rise up on the Senate floor and defeat the committee bill.

"We haven't stopped a goddamn thing in that committee," said CMA President Robert Roland before the bill passed, "but we have indications that a lot of people will support us on the floor."

The current House version is "a more reasoned approach," Roland added, calling the Senate committee product yesterday "impractical, unnecessarily broad and punitive." Any fund financed by the industry is "still repugnant," he said.

The Senate approach would raise $4.1 billion over the next six years by assessing assorted production fees on the 45 basic petrochemicals, raw materials and crude oils used to make most hazardous substances: $250 million in fiscal 1981, $525 million in 1982 and $700 million in each of the years 1983 through 1986. Another $35 million in federal appropriations would be added next year, $75 million in 1982 and $100 million in each of the next four years.

The resulting fund would be available to pay immediately for removal of waste from a newly found site, decontamination of the area and for studies of chemical content and its effects on the environment and people involved.

It would compensate proven victims of the waste for their out-of-pocket medical expenses and crop or other economic damages if claimed within three years of discovery of exposure, retroactive to Jan. 2, 1977. Medical expenses for six years from the time exposure was discovered would be paid, a time period explicitly chosen to avoid fund liability for diseases like cancer that do not show up for 20 years or more, according to a committee staff member.

For example, residents of the Love Canal area were exposed to the wastes buried there beginning in 1960, but their exposure did not become known to them until 1978. Under the bill, they could collect from the fund for their medical expenses until 1984 if they file their claims before the end of 1981.

The House version provides no medical compensation but would pay only for cleanup. Even that is considered a major step, since the Environmental Protection Agency estimates that as many as 30,000 abandoned waste dump sites may exist nationwide. Perhaps 1,200 to 2,000 are likely to be extremely hazardous.

The most controversial section of the Senate committee bill, and the one most likely to lead to a floor fight and still House resistance, is the provision that makes it easier to establish damage claims.

Those bringing suit need only show that they were significantly exposed to the hazardous substance and that there is a "reasonable likelihood" that such exposure can cause or contribute to the kind of illness or injury claimed.

"Then it shall be presumed that defendant caused or significantly contributed to that injury or disease," the bill says. Provisions that would have made things even tougher on chemical producers by requiring them to show by "a preponderance of the evidence" that they were innocent were knocked out during the final markup sessions.

Still, the easing of evidentiary requirements for the plaintiffs would make legal history. Environmentalists were pleased. "It has the essential elements of a good bill," said David Lennett of the Environmental Defense Fund.