The CEOs of several major artificial intelligence companies are urging Congress to adopt new laws that would make it harder for bad actors to develop biological weapons using their technology. Google DeepMind’s Demis Hassabis, OpenAI’s Sam Altman, Anthropic’s Dario Amodei, and Microsoft AI’s Mustafa Suleyman are among the signatories on a public letter calling for laws requiring companies that sell synthetic DNA and RNA to screen customers and orders.

Organized by the nonpartisan Institute for Progress and the right-leaning Foundation for American Innovation, the letter acknowledges that given the pace of AI development, “there is a real possibility that the knowledge barriers which have historically prevented bad actors from obtaining biological weapons will meaningfully erode.”

In 2017, Canadian researchers raised alarm when they used $100,000 worth of mail-order DNA to reconstitute the extinct horsepox virus. Critics said the same methodology could be used to construct smallpox, a closely related and deadly virus. Gene synthesis has only gotten cheaper since then.

Combined with advances in AI, it’s now feasible to design dangerous new toxins and pathogens using large language models, although some biology training would likely still be needed to make a functional virus from scratch. While bioterror attacks have been rare, they have the potential to cause mass casualties, public panic, and economic loss.

A major concern is that an AI-designed pathogen could intentionally or unintentionally spark a global pandemic. “AI tools enable a user to very quickly identify where to turn to order sequences that will not be subject to screening,” says David Relman, a microbiologist and biosecurity expert at Stanford University, who signed the letter.