Hook and Loop Material
Most hook and loop material is made out of nylon which is hydrophobic. This means that it does not easily absorb water. Other materials that hook and loop are made out of like polyester and assorted plastics are also hydrophobic. So almost any hook and loop fastener you purchase does not easily absorb water. So how does this impact washing it? This means that anything that gets onto the hook and loop will remain on its surface so simply laundering the material or soaking it in a cleaning liquid should remove anything that needs to be washed off. If the hook or loop may have absorbed something that needs to be washed out, they'll need to be soaked for an extended period.
The exception here is adhesive backed hook and loop. If you wash hook or loop with adhesive backing, moisture and chemicals can impact the performance of the adhesive, particularly a rubber based adhesive. An acrylic based adhesive holds up better to these outside factors. In most instances though, the hook and loop getting washed is sewn to clothing and other apparel. The only thing to consider when washing hook and loop is the temperature the hook and loop can withstand. This varies based on material and manufacturer, but for example our DuraGrip Brand nylon hook and loop can withstand up to 280 F which is high enough for some autoclaves.
Washing Hook and Loop
The most important part about washing hook and loop is to make sure the hook and loop is fastened together before going through a wash cycle. If it's not fastened together, the hook side will snag onto other clothing and damage those items. The hook side also collects a bunch of lint and debris from the laundering process that can essentially render it useless. There are ways to clean out the hook side after the fact, but it's much easier to just make sure the hook side is fastened so it is not exposed in the wash.
So you can wash hook and loop without much worry as long as there is no adhesive backing to consider and you make sure the hook and loop sides are fastened together beforehand.