After about a week of looking into this same topic, I am not seeing data that backs up the idea that “interior grade” ply is formaldehyde-free. It typically is bonded with urea-formaldehyde or melamine-urea-formaldehyde. This means its easier to laser cut, but it does not mean it has less formaldehyde. In fact, exterior grade, which uses a phenolic formaldehyde resin, actually off-gases less than the interior resins. While it doesn’t make sense, that’s what I’m seeing. The phenolic allows the ply to be more water proof and somehow holds the formaldehyde in better, but does not laser cut well at all. Some great keywords to look for are NAF (no added formaldehyde) or ULEF (ultra low emitting formaldehyde). Pure
Bond ply is NAF. Its a Columbia Forest Products plywood is offered through some Home Depots and other distributors. SoyStrong is another brand that is NAF or ULEF to look for. If I’m wrong, and you’ve got good links to back it up, I would love to know because it would help me out a lot as well, but after way to much research, this is what I’ve found.