I probably wouldn't throw those out so quickly, this is mostly focused on the imported cheaper ones from department stores (I think).

Can anyone clarify - are these the ones with the alphabet on them, or the ones with the alphabet inserts? We got given secondhand ones a few years ago, no idea where they came from but they are the small interlocking ones where the letters and numbers pop out.
Hun, the ones they are talking about are the 'interlocking alphabet/other designs' play mats made in China. I got mine from Kmart and it came in small colourful squares that clicked together and then you had to click in the edges. I imagine the other mats that are similar that were made in China fall into the same category.

Shanti, I'm interested too where you got your mat from, the one that is safe for baby