Silicone seals are dishwasher-safe—the real risk is leftover water

Yes, it’s safe—silicone handles dishwasher heat easily. It’s rated for around 400°F, and even the harshest dishwasher cycle tops out around 170°F with heated dry. The seal won’t melt, warp, or leach anything weird.

The actual problems are moisture and wear. Water loves to get trapped between the seal and the lid. If you pull the lunch box out, snap it shut while it’s still wet, and stick it in a bag, you’re basically farming mold. Pop the seal out and let both parts dry separately before you reassemble.

The second thing: repeated hot washes eventually make silicone less springy. That’s not a safety issue, but after a few hundred cycles the seal might stop being truly leakproof—which defeats the whole point. Premium brands often say “hand wash only” for that exact reason, not because the dishwasher will destroy the thing.

Run it through the dishwasher if you want—just let the seal dry on its own before you snap it shut.