I work a lot with Urea-Formaldehyde resin/plastic, both in carpentry and textiles. Cleanup while still uncured is simple enough. Cleanup before even mixed is easy enough. What I don't know, is how to cleanup plastic that has set and cured. If it was reasonably safe to guess and try, I would, but in this environment/conditions acetaldehyde formation is very possible, which makes release formaldehyde a problem. Grinding or sanding the plastic is not an option. I haven't seen a MSDS say anything about cleaning up cured plastic. From accidental spills it doesn't seem to disolve in xylol, acetol, or toluol. Anyone have any ideas? As long as there is a preditable outcome I have the resources to test just about anything.
It appears it can be decomposed in the presence of Hydrogen Peroxide, with decomposition being noticeable even at 3% (extremely slowly), but working well around 12%. I didn't do anything beyond basic tests, but a white salt (likely Urea?) will precipitate out, embedding in the pores, if any, of the plastic; this can interfere with this clean up method. It also produces Aldehydes, seemingly mostly Formaldehyde from the odor, but with reactions based on the environment. Some Acetaldehyde was produced in my case, but the rate was slow enough that only small short lived flames were produced.
This was able to be sped up with heating or HCl. I would shy away from adding HCl, as it produced a strong Chlorine smell, without any obvious yellow gas.