BLUE TONGUE SKINKS

I'm looking into materials to build a cage for Dulcia, my northern bts. I have been looking around here on the forum and I see that melamine coated particleboard or fiberboard are pretty popular choices.

Is this the best material to use? Is there no concern over the use of formaldehyde as a bonding agent between the wood particles and the melamine?

I wouldn't necessarily say it's the "best" material, but I have made multiple enclosures out if it and I like it a lot. There are other plastic type materials that I would prefer, but they are cost prohibative because of the large number of enclosures that I need. I think melamine is one very good option, and have no concerns over health issues from using it.

Ive had some lizards continuously in melamine for 17 years with no issues

Formaldehyde is combined with melamine to make it heat stable to +100°C and not to soften at lower temperatures like other polymers. The health issue with melamine is related to ingestion where it has been implicated in renal disease, especially calculi.