Lots of plastic items (recently on the global market) have residual solvents used in the plastic manufacturing process distinctly evident in their odors. Most of these can be distinguished as aromatics like xylene. Everything new in our house sits out in the open air with lots of sunshine to allow it to get a good airing out. Sometimes it takes weeks.
If the object is small enough to put in a vacuum chamber (vac desicator) and pumped down, it could evaporate sooner.
After getting most of the volatiles removed, a surface washing with a mild detergent can get some additionally adsorbed material and any polar solvents that are less volatile. Some of these are residual plasticizers, and monomers or crosslinking agents. If the item is from polyurethane, the residuals can be isocyanates that will hydrolyze under the conditions of washing alternately with baking soda, soapy water, then vinegar, followed by water. Isocyanates are known to be skin sensitizers to some people.