The move comes just over a month after the National Uniformity for Food Act was approved by the House of Representatives.
The proposed bill, which is now due to be considered by the Senate, has sparked fierce debate between supporters, who claim the legislation would establish a uniform national system of food safety, and opponents, who say the bill would dissolve state food safety protections.
The state law that would be particularly affected by the National Uniformity for Food Act is California's Proposition 65, which requires that food manufacturers alert customers about the existence of cancer-causing compounds in food.
Governor Schwarzenegger on Tuesday announced his opposition to the bill in a letter to California's Democratic Senator Diane Feinstein.
He expressed "deep concern regarding the potential consequences this legislation could have on our consumers and public health," adding that the citizens of California "fought hard to provide warning labels on products that knowingly expose individuals to any substance that may cause cancer, birth defects or other reproductive harm."
At a news conference on Wednesday, Senator Feinstein and Senator Barbara Boxer also denounced the bill and vowed to oppose it when it comes before the Senate.
"Since 1986, California's Prop. 65 has been a shield for consumers. The legislation passed by the House would do away not only with Prop. 65, but with more than 200 food safety laws and regulations on the books in all 50 states. Overriding these stringent consumer protections gambles with the health of hundreds of thousands of Americans. I will do everything in my power to stop this legislation from passing the Senate," said Senator Feinstein.
According to Governor Schwarzenegger, some of the limits set by Proposition 65 include reduced levels of lead in certain candy products, mercury warnings on fish products, and a removal of arsenic from certain bottled water.
"Any weakening of Proposition 65, or any other state or local food safety measure, could undermine the health and safety of all Americans," says Senator Feinstein's website.
Other state laws that could be affected by the proposed bill include laws in Illinois and Pennsylvania regulating the safety of eggs; laws in California, Florida, and Louisiana requiring warning labels on shellfish; regulation for smoked fish in Wisconsin and Michigan; and laws in Maryland requiring that labels disclose if "fresh" food was previously frozen and thus should not be refrozen.
"This is a terrible, terrible bill," said Elisa Odabashian, senior policy analyst of Consumer's Union, the non-profit publishers Consumer Reports magazine.
"The food industry has been trying to kill Prop. 65 for a number of years. This is another attempt," she told FoodNavigator-USA.com.
But despite the opposition it is receiving from various sources, the bill was supported by 283 Members of Congress, representing 44 states, including Califonia.
It is also attracting strong support from the industry, including major ingredients and food firms such as Cargill, ConAgra Foods and General Mills. These claim that the bill takes a "measured, science based approach, to achieve national uniformity" through an "orderly review and harmonization of existing state food adulteration laws and warnings."
"The legislation will bolster consumer confidence in food labels because the information will be consistent from state to state and formulated by the US Food and Drug Administration (FDA), the world's leading food safety agency," said the industry body Grocery Manufacturers Association (GMA) in response to the Senators' comments earlier this week.
"Establishing a uniform national system will put food safety in the hands of the nation's top food scientists and food safety experts. Rapid developments in food science can result in conflicting and confusing information, and FDA is best positioned to protect all consumers by reviewing the entire body of scientific evidence and issuing the best possible food safety regulations," said Susan Stout, the GMA's vice president of federal affairs.