For the record, formaldehyde shows up in only one group of finishes we woodworkers use: the so-called catalyzed and pre-cat lacquers and conversion varnishes. It is not in shellac, lacquer, oil varnish, water-based lacquers, oil- or water-based polyurethane or even two-part automotive polyurethanes or polyesters.
Cabinetmakers who use catalyzed finishes are justifiably concerned about their workers and generally insist they wear protective gear when spraying these finishes. However, there is little concern about the end-user of the finished product. That’s because the formaldehyde dissipates within a month. By the time it comes into your home, it is no longer offgassing formaldehyde.
It’s worth noting that some interior plywood off-gasses formaldehyde, depending on the type of glue used. Sealing the plywood with a film-forming finish blocks its release.Thus, while one type of finish can release formaldehyde, almost any other finish can block it.