Although it may look very sturdy, and its main purpose is to stop a bullet, a ballistic vest is not indestructible. Even with proper maintenance, body armor will expire at some point, and it is recommended that you exchange your plates at least once every five years.
Additionally, any type of wear and tear, especially exposure to very low temperatures and direct sunlight, will reduce this time significantly.
There are three questions to ask when deciding if it’s time to change your body armor:
- Is it damaged/ shot?
- Are there signs of use?
- What does the label say?
Obviously, if the answer to the first question is yes, you will need to change the plates or panels as soon as possible. But, the fact that there is a bullet logged in your armor doesn’t mean it is instantly useless. Rather, a good NIJ-tested vest will withstand up to six shots before losing its structural integrity.
Damage from Impact
When it comes to body armor, and especially hard plate ballistic armor, there are two types of impact damage.
Primarily, there is damage taken from ballistic projectiles. This can be either bullets or shrapnel and it will reduce structural integrity quite a bit. But, unless the armor gets shot in the same spot repeatedly it should stay sound for several shots.
A much more dangerous type of damage is that from blunt impact. Throwing the plate around can make lateral cracks that will severely reduce the toughness of the plate. If your plate is damaged in such a way you should exchange it immediately.
Damage from Exposure
Both hard plates and soft panels are very resistant to dust and heat. But, they are not so resistant to wet, cold, and sunny. Sunlight irradiates the surface of the plate and slowly makes it lose its molecular structure. This is why plates should always be covered with some kind of mesh to reduce the tear.
If stored improperly, body armor will expire in less than 18 months. Being left to freeze twice will half its structural integrity.
The only thing good body armor will never do is spoil. The materials used are very internally stable and with proper care, they will last for a very long time. The half-life of Aluminum is roughly 700.000 years, so you are safe on that front.
But, the paint will chip and there will always be other factors affecting the armor. This is why you always need to maintain it and still buy a new one after the recommended period. Always better safe than sorry.