It’s the latest round in the companies’ ongoing feud over AI safety and regulation, as their CEOs have traded internal and public barbs over each other’s approach. 

OpenAI is backing SB 3444, under which frontier AI developers would not be liable for causing death or serious injury to 100 or more people or causing more than $1 billion in property damage. This protection includes cases when AI causes or materially enables the creation or use of chemical, biological, radiological, or nuclear weapons.

This week, Anthropic said it opposes the bill, Wired first reported.    

“We are opposed to this bill. Good transparency legislation needs to ensure public safety and accountability for the companies developing this powerful technology, not provide a get-out-of-jail-free card against all liability,” Cesar Fernandez, head of U.S. state and local government relations at Anthropic, said in a statement to Fortune. 

Anthropic is instead supporting a separate bill, SB 3261, which would require AI developers to publish a public safety and child protection plan on their website. The bill also creates an incident reporting system to inform legislators and the public of “catastrophic risk,” or an incident that could result in the death or serious injury of 50 or more people caused by a frontier developer’s development, storage, use, or deployment of a frontier model. 

The bill also covers children’s safety, an aspect missing from the OpenAI-backed bill. Under SB 3261, AI developers would be held liable if their model causes a child severe emotional distress, death, or bodily injury, including self-harm. 

A ‘very low’ bar

Experts told Fortune that SB 3444 is unlikely to pass as it’s a markedly weak approach to corporate liability in the case of catastrophe while Illinois has been a leader on AI regulation. Last year, the state banned AI therapy while allowing its use in administrative and support services for licensed professionals. 

SB 3444 requires companies to have a public AI safety plan, but there is no measure for enforcement. If developers did not “intentionally or recklessly” cause the incident, they would be protected from liability. 

Intentional or reckless is not a common legal standard of care for companies engaging in highly dangerous activities, said Anat Lior, an assistant professor of law at Drexel University, who is an expert on AI liability and governance.

“Typically, the state of mind, or the fault associated with the harm, does not matter,” she explained. “They are setting the bar very low here. Being able to prove that you did something intentionally that involves AI is going to be very hard.” 

Touro University law professor Gabriel Weil, who has collaborated with lawmakers in New York and Rhode Island on bills that would put greater liability on AI developers, said the OpenAI-backed bill’s approach is “pretty indefensible.” 

“That seems like a very weak requirement, and in exchange you get near total protection from liability, from these extreme events,” Weil told Fortune. “I think that’s the opposite direction that we should be moving in.”

An OpenAI spokesperson told Wired that the company supports SB 3444’s approach because it reduces “the risk of serious harm from the most advanced AI systems while still allowing this technology to get into the hands of the people and businesses.” 

An OpenAI spokesperson told Fortune that the company strongly supports efforts that improve the transparency and risk reduction in AI safety protocols, citing its collaboration with lawmakers in California and New York to pass safety frameworks and noncompliance penalties. The company will continue to work with states in the absence of federal legislation. 

“We hope these state laws will inform a national framework that will help ensure the U.S. continues to lead,” the spokesperson wrote.