If you never hit the supermarket without your trusty reusable shopping bags, you’re in good company. Over the last decade, cloth totes have become increasingly popular among shoppers. But what many of us forget about these everyday workhorses is that they need to be cleaned. After all, anything that habitually comes into contact with shopping carts, checkout counters and train, car or bus seats — not to mention perishable grocery items — is bound to pick up grime and bacteria.

So, what’s the best way to wash reusable shopping bags? It all depends on which types of bags you use. Here’s everything you need to know.

How to Wash Cotton Bags

Cotton totes — the kind you might get for free when you subscribe to a magazine — are among the easiest reusable shopping bags to clean.

Step one: Empty the bag. Food scraps like onion skins can get caught in the seams. Make sure your bag is completely empty to keep your laundry machine clean.

Step two: Machine wash. Use cold water the first few times you wash it, especially if the bag is brightly colored or has text or designs screen-printed onto it. After the first few washes, you can use warm water if you prefer.

Step three: Line or machine dry. If you opt to put the bag in the dryer, it may shrink at first but will still be perfectly useable.

Step four: Store in a cool, airy space. Make sure the bag is completely dry before you put it away.

How to Wash Polypropylene Bags

Many grocery stores sell reusable bags made from polypropylene, a lightweight thermoplastic sometimes crafted from recycled plastic containers or water bottles.

Step one: Empty the bag. Food scraps like onion skins can get caught in the seams. Make sure your bag is completely empty to keep your laundry machine clean.

Step two: Machine or hand wash in cold water. Use the gentle cycle if you use the washing machine.

Step three: Line dry. The hot temperature of a machine dryer can warp thermoplastics, so line drying keeps your bag (and dryer) in peak condition.

Step four: Store in a cool, airy space. Make sure the bag is completely dry before you put it away.

How to a Clean a Canvas Bag

If your canvas bag is entirely white or beige with no hardware or trim, check the interior tag for care instructions: you might be able to clean it in the washing machine. However, if it has a pattern or text printed onto it, a brightly colored trim or any other accessories, it might need a little more TLC.

Step one: Empty the bag. Make sure there’s nothing lingering in the pockets.

Step two: Turn the bag inside out (if possible). Use a lint roller, the fabric attachment on a vacuum cleaner or dampened paper towel to remove any crumbs or debris from the seams or crevices.

Step three: Hand wash in cool water. Use a clean white cloth to rub the interior and exterior of the bag with a gentle circular motion.

Step four: Add soap only if needed. If the bag needs additional cleaning after its initial soak, add a few drops of detergent into the water and scrub again with the same white cloth.

Step five: Rinse. Make sure the entire bag gets thoroughly rinsed in a fresh batch of cool water.

Step six: Line dry. Canvas bags can lose their shape in a machine dryer. Plus, the hot temperature of a dryer can damage details like leather trim.

Step seven: Store in a cool, airy space. Make sure the bag is completely dry before you put it away.

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