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Is Body Armor Waterproof?

Is body armor waterproof? What NIJ, CJTTEC and published research say about water and armor fibers, how the standards have conditioned armor for it, and how CJTTEC says to keep panels dry.

ArmorList Editorial·January 18, 2025·5 min read

Is body armor waterproof? The question comes up for anyone who wears body armor, in law enforcement, the military or for personal protection, and works in rain, sweat or near water. The short answer from the sources is that water is something armor is tested and cared for against, not something it is promised to be immune to.

Body armor is a substantial purchase, and keeping it in service matters as much as choosing it. It is tempting to assume armor is waterproof; the record is more specific than that, and it starts with the materials.

Understanding body armor materials

Soft body armor is built from layers of ballistic fibers, and hard armor plates from ceramics, steel or polyethylene, often with a fiber backing. Kevlar is a para-aramid fiber that Stephanie Kwolek invented at DuPont in 1965 (the brand now belongs to Arclin), and Dyneema is a trademark for an ultra-high-molecular-weight polyethylene (UHMWPE) fiber; the names identify fiber families, not the quality of a given product.

Water and aramid have been studied. A 2016 study of para-aramid fabrics, including Kevlar 129, found that their V50 fell after immersion in water, even for fabric with a water-repellent finish, and named yarn slippage as the main mechanism. NIJ says moisture, along with heat, light, detergents, friction and stretching, may contribute to the degradation of fibers used in body armor.

We found no NIJ or NIST source on how water affects the ballistic performance of UHMWPE armor or of ceramic plates (checked 1 October 2026). Many makers sell covers or treatments they describe as water-resistant; what a cover does is the maker's statement for that model.

For more on the materials, read Materials Used in Armor Plates Explained.

NIJ has published its own count of what armor has done in the field: in October 2006, it wrote that the body armor its standards and testing cover had been in use for 30 years and had saved at least 3,000 officers' lives. Keeping armor in the condition it was tested in is part of that.

How water affects body armor

For soft armor, the sources point the same way: water can lower the ballistic performance of wet aramid fabric (the 2016 study), and moisture may contribute to fiber degradation over time (NIJ). NIST found moisture was a key factor in the loss of strength of PBO (Zylon) fibers, while it found p-aramid yarns generally resistant to heat and humidity, with changes of less than 10% only at the harshest conditions it tested.

For hard armor, we found no NIJ, CJTTEC or NIST source on water entering cracked plates (checked 1 October 2026). CJTTEC advises against dropping ceramic plates on hard surfaces, which can cause breaks or cracks that can affect performance, and warns against assuming that a plate's good appearance means good performance. Our advice: inspect armor after it has been soaked, and treat a damaged plate as a question for the manufacturer.

Waterproof vs. water-resistant armor

"Waterproof" would mean armor can be submerged with no effect on it; "water-resistant" means a cover or treatment repels some water. We found no NIJ or CJTTEC definition of either term for body armor (checked 1 October 2026), so both are the maker's words.

CJTTEC's care guidance treats ballistic panels as something to keep out of water: it advises against rinsing, soaking, submerging or spraying panels. Cordura is a trademark for a durable fabric used in some carriers and covers; whether a given cover repels water is the maker's specification.

Read the manufacturer's specifications and care label for the exact model. CJTTEC notes that NIJ requires manufacturer care instructions on the label of every compliant model.

For the levels armor is tested to, read Breaking Down Hard Body Armor Levels.

Testing water resistance in body armor

The standards have conditioned armor for water before shooting it. NIJ 0101.06 required new flexible armor to be submersed in water and tested wet. We found no NIJ public page stating whether 0101.07 keeps water submersion for soft armor (checked 1 October 2026). For hard armor, ASTM E3078, the practice NIJ 0101.07 Addendum 1 names for hard armor conditioning apparatus, includes weathering and fluid exposure procedures among others; users of the practice choose which apply.

Our advice: check the model on the Compliant Products List (CPL), with the standard it is listed under and the date you read it, and read what that standard did with water. For armor outside the NIJ program, ask the maker which standard or lab test covered wet conditions, and for the report.

On ArmorList, a product's record shows its NIJ CPL status with the date the list was read, and the standards it was tested to.

Tips for protecting your body armor from water

CJTTEC's guidance, and the maker's label, come first:

  1. Store armor flat at room temperature in a dry, shaded place, out of places where temperature, light and humidity are not reasonably controlled, such as a vehicle trunk (CJTTEC).
  2. Clean the panels by wiping the outer cover with a damp sponge or soft cloth and cold water; never rinse, soak, submerge or machine wash them (CJTTEC).
  3. Air-dry the panels flat, without folding or creasing them (CJTTEC), and wash the carrier separately as its maker directs.
  4. Inspect armor after it has been soaked, and log the exposure (our advice).

For more on care, read How to Maintain and Care for Body Armor.

Conclusion

Body armor is not sold as waterproof, and the sources treat water as something to test for and keep away from the panels. Research and NIJ say water and moisture can affect aramid fibers; NIJ 0101.06 tested soft armor wet; CJTTEC says to keep panels dry and never submerge them.

Before relying on armor in wet work, read the model's care label and specifications, check its listing with the date you read it, and ask the maker what its water claims rest on. For costs, see What Does Body Armor Typically Cost?.

Sources

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