If you work in the construction industry, your hard hat may be your only line of defense against a catastrophic head injury. Consequently, before working in any place where your head may be in danger, it is critical to put on the right type of hard hat for the project.

While hard hat manufacturers typically design their products to put up with considerable punishment, your hard hat is not indestructible. Because wearing an old, damaged or ineffective hard hat may put your life in jeopardy, you should replace your headgear after any of the following.

1. You sustain a head injury

Your hard hat has a hard outer shell and an interior grid to protect your head from injuries. If the hard hat does not do its job, you should no longer continue to use it. This is true even if the hard hat appears to have sustained no damage in the incident that caused your head injury.

2. You drop the hard hat

When something hits hard hats, they may develop small or even imperceptible cracks that weaken their integrity. Therefore, you should always replace your hard hat after an impact. Dropping your headgear constitutes an impact, even if the drop is only a few feet.

3. You have had the hard hat for some time

Like your other work tools, your hard hat may deteriorate over time. Dirt, oil, sweat and grime may speed up this deterioration. Accordingly, if more than a couple years have passed since you purchased your hard hat, it may be time to replace it.

Your hard hat’s manufacturer probably has specific guidelines for how long it is safe to use your headgear. Ultimately, though, if you have any questions about your hard hat’s ability to protect your head, it may be a good idea to invest in a new one.