According to Good Housekeeping, iron scorch marks that have set into clothing are removed by applying hydrogen peroxide and ammonia directly to the stain and allowing it to stand for up to an hour. The next step is to flush the stain with cold water. The last step is to machine wash the garment in cold water with oxygen bleach.
Fresh scorch marks are treated by rubbing laundry detergent directly onto the mark and laundering the garment immediately with liquid laundry detergent and oxygen bleach. Applying distilled white vinegar directly to the mark and wiping the area clean with a soft cloth also helps to remove fresh scorch marks. For fuzzy or thick fabrics, it is important to brush the fabric to remove charred fibers prior to washing. If scorch stains remain after treatment, it is important to wash the garments again with an all-fabric bleach.
Heavily scorched garments that have multiple burnt fibers or melted areas of fabric are typically permanently damaged and cannot be treated. Certain synthetic fabrics, such as acrylic, nylon, polyester and acetate, cannot be repaired if scorched. Scorched cotton, linen, wool, rayon and ramie fabrics are treatable if the fabric is not severely damaged. Areas of clothing that are treated for scorching are typically weaker than the surrounding fabric, so it is important for individuals to take extra precautions when wearing the garments to prevent additional wear and tear.