Whether you placed a bread bag, plastic utensil, or some other plastic item on your hot cast iron stove, the result is the same--gooey plastic that stretches or spreads when hot, or hardens into an immovable lump if allowed to cool. As melted plastic releases toxic fumes when burnt, cleaning melted plastic from a cast iron stove is necessary to maintain healthy air quality in your kitchen. Fortunately, cleaning hot or cold melted plastic off cast iron stove surfaces isn’t difficult.
Open any windows and turn on your kitchen exhaust fan.
Turn the burner or oven to a low temperature so the plastic hardens slightly.
Place your razor blade scraper at the edge of the plastic.
Push the melted plastic off the warm surface and onto a nearby cool area.
Turn off the burner or oven completely and scrape away the plastic as it continues to cool.
Treat the area with a solvent such as rubbing alcohol after the stove completely cools. This will break up or dissolve and remove any remaining plastic film or residue.
Wash the area with a slightly soapy microfiber cloth, rinse thoroughly with a damp cloth, and wipe dry.
Place the blade edge of your razor blade scraper on one side of the plastic at a 30-degree angle.
Push the blade edge against the plastic.
Repeat until the plastic pops off the surface, or, if dealing with a thin film, scrapes from the surface.
Fill a bag with ice, place it on top of the plastic, and wait 20 to 30 minutes until the ice makes the plastic brittle if you couldn't remove the plastic with a scraper.
Scrape the brittle plastic from the surface.
Blot any remaining plastic residue with a solvent and a cloth until the residue wipes off the surface.
Wash the area with a slightly soapy cloth, rinse thoroughly with a damp cloth, and wipe dry.
Test any cleaning method on an inconspicuous area of your stove before attempting to remove the melted plastic--especially if using a solvent on a painted cast iron stove--because some methods may damage the stove’s surface. Take extra care if using a razor blade scraper on a porcelain-coated cast iron stove, because a razor blade can scratch or nick porcelain. Never use any cool or cold substances on hot porcelain to remove plastic. Instead, always wait for the porcelain to cool first, since hot porcelain will crack if exposed to an extreme temperature change. Always dry your cast iron stove thoroughly when finished cleaning, because unfinished cast iron can rust, and porcelain-coated cast iron can dry with water spots.