Hard Hats Curbside Trash Replace Hard Hats Often Hard Hat shells need to be replaced every 2-5 years depending on the environment they’re used in, and they need to be replaced immediately if they are struck by anything. Inner suspension needs to be replaced every 12 months. Refer to your hat manufacturer for explicit safety recommendations. Ways to Reuse Turn Your Hard Hat Into a Planter You can repurpose old or unwanted hardhats as outdoor hanging planters. Get inspiration from these examples on Pinterest. Did You Know?