Grey metal marks can be commonly found on all glass products. These marks is caused by friction between glass and metal such as using metal utensils, silverware, exposed metal on dishwasher racks or stainless steel sinks. Metal utensils should not be used with CORNINGWARE. Instead use wooden, nylon or plastic utensils.
Tips: To loosen food, allow cookware to soak and use only plastic or nylon cleaning pads with non-abrasive cleansers such as CORNINGWARE Cleaner & Conditioner. A soft sponge with a non-abrasive cleanser may also remove the grey marks on your CORNINGWARE .
All CORNINGWARE cookware can be used in conventional, convection, toaster and microwave ovens; gas and electric stovetop; in the refrigerator, freezer and dishwasher. For use in freezer, please use with caution as liquid expansion may cause possible pressure for glass to break.
CORNINGWARE cookware is made of a highly heat resistant and durable glass ceramic material. It is very heat resistant and does not stain or retain odors as will plastic cookware. It is easy to clean and is harmless to health.
Generally you should not use any chipped, cracked or broken glass product. The glass item can be very risky. Hence, do not use damaged CORNINGWARE cookware or PYREX glass cover.
To loosen cooked-on food, soak cookware in mild warm soapy water or in vinegar and water mix with the ratio of 1:3 for long hours. CORNINGWARE cookware retains heat so well; you can use a lower heat setting than normal and save on energy. This also helps prevent sticking or burning of food. Use only plastic or nylon cleaning pads, as metal harsh scouring pads can leave grey marks on CORNINGWARE cookware surface.