Jane,

Thank you for your question and what a great one too! Older types of ground-contact treated lumber (also referred to as "green lumber") are not safe for vegetable garden beds.

On the other hand, modern versions of ground contact-rated lumber that use micronized copper azole (aka MCA or AC2) are safe for use as the structural material for raised beds.

MSU extension does not endorse any particular brand or product, but here is a manufacturer's information page about their product which uses MCA/AC2 treatment.

https://www.prowoodlumber.com/inspiration/tips-from-the-pros/how-is-prowood-prioritizing-sustainability

When in doubt, speak directly with the inventory manager of your hardware store to ensure that the product you are purchasing uses MCA/AC2 and not the treatment ACQ or CCA. They all have the word "copper" in them, but MCA/AC2 is regarded as the safest alternative of the three.