Snapware Total Solution Plastic Storage Use & Care: Do not use lids in conventional or convection ovens, under browning elements, or on stovetop. Snapware plastic lids can be used in a microwave oven, refrigerator, or freezer. When using in a microwave, unlatch lid and offset slightly from container. Do not use in conventional or convection ovens, under browning elements, or on stovetop. Before first use, remove gasket from lid and wash vessels, gaskets and lids thoroughly. Snapware can be washed in the dishwasher, top rack only, or by hand in hot soapy water. After cleaning, reassemble by pressing gasket firmly into lid. Avoid cutting food inside the vessels with sharp utensils. Avoid abrasive cleaners and scrub pads. To prevent staining and blistering, avoid overheating of high-fat foods, sugar, oils and tomato sauce. To Write-On use a soft tip non-toxic permanent or wet erase marker in the write here area only. To remove markings, rub using a soft cloth or paper towel or wash the lid. If the ink becomes hard to remove, a few drops of isopropyl alcohol can be used to remove writing.