In medical and clean room environments free floating particles are a concern because of possible contamination of products and people. One of the benefits of our rotary viscous dampers and friction hinges is the lack of particulation. We have no metal on metal contact and our functional contact areas where the fluid is sheared is internal to the product.  We therefore have no possibility of contaminating a clean room with our product. Also the exposed surface of our product does not particulate or break down at all.  Mechanical Motion Technologies uses environmentally friendly cleaners to remove all particles from the individual components as well as the final delivered, assembled product. If special materials or products are required for your project contact us for consultation at www.mmtech.us