Dozens of consumer and food groups and businesses asked the U.S. government on Monday for tighter regulation of genetically engineered crops, calling the current system a "failure."

The U.S. Department of Agriculture has said it was considering changes to the way it regulates biotech crops and set a public comment period that expired Monday.

The agency had proposed a regulatory rule in 2008 after being cited in a government audit for holes in its oversight, criticized in court rulings, and after high-profile GMO contamination events that led to food recalls and trade disruption.

The USDA never finalized that proposal and withdrew it earlier this year.

Before Monday, USDA had received comments from more than 74,000 "signatories," said spokesman Richard Bell. He said "comments received are thoroughly analyzed and used to assist with the decision-making process."

In the recommendations filed on Monday, the groups said the government needs to do more to adequately protect the "environment, economy, farmers, consumers and public health."

The groups signing onto the recommendations include the National Family Farm Coalition, the Organic Consumers Association, Clif Bar & Co, Nature's Path and 34 other organizations.

Currently, the USDA's Animal and Plant Health Inspection Service (APHIS) can grant new genetically altered crops "nonregulated" status if developers demonstrate that tests show the new crops do not pose a risk to plant health.

But the groups called on the agency to expand its work to assess the safety of GMO crops for human and animal consumption, and closely monitor genetically engineered crop production systems for weed resistance problems or harm to ecosystems. They also said the agency needs to work harder to prevent contamination of non-GMO crops by GMO crops.

The USDA's APHIS said it places a "high priority" on the feedback it is receiving.

Biotech crop supporters say there is a wealth of evidence that the GMO crops on the market are safe and already well regulated. Critics argue that the U.S. government conducts no independent testing of these biotech crops before they are approved and does little to track them after.

"Our public agencies cannot rely on the corporations that profit from sale of GE crops to decide how many and what kinds of tests to conduct, or what information is shared with regulators and the public," Marcia Ishii-Eiteman, senior scientist at Pesticide Action Network North America, said in a statement.