Hand wash it, don’t machine wash it.

Hand washing with mild soap and warm water is the safest way to clean a fabric lunch box with a plastic lining. Skip the washing machine unless the tag explicitly says it’s fine.

For the inside, use a soft cloth or sponge dipped in warm water with a drop of mild dish soap. Wipe down the plastic lining, then go over it again with a clean damp cloth to rinse. Don’t soak the whole bag — water can get trapped in the fabric layer or insulation and cause the lining to peel.

For the fabric outside, spot clean with a damp cloth and a little detergent. Be gentle, especially around seams. Then leave the bag open and let it air dry completely before storing it. A good overnight dry keeps mildew away and makes the whole thing last much longer.

Think of it like caring for a decent jacket: a little patience beats drowning it in a machine.