I'm sharing this product, only because it was SO HARD to find it.
Akiva recently started asking me "What does this say?" when he sees words printed on things. So I'll tell him, and he's gotten curious about what letters are. He's really into O right now. But we haven't had any toys with letters and numbers on them around the house, and so the only place Akiva can practice finding O's when the passion hits him is on Matt's text paintings:

So I wanted to find some alphabet fridge magnets. And since Akiva is only 21 months old, he still is tempted to put everything in his mouth. So I didn't want plastic. I looked for wood. The only ones I could find were Melissa & Doug. And I read the "review" of them because why not. And some fellow paranoid parent had bought them and actually sent them to a lab. The magnet on the letters tested high in lead! Yikes. I searched and searched and finally found these cuties by a company called Rubbabu:
Made of natural rubber. Here's the safety info. Only problem is that if you don't live in Spain, you have to buy it from some website that charges a lot of money to ship it possibly from Spain? Ours are in the mail. Happy speling.