QS is short for Quality Safety which is the approved by China. All food and food-contacting substances must passed QS certification in Chinese market. As one of liquid food bag factory, if Uni-Pak want to sell their products in China market, we must do this test.  Uni-Pak passed this test in 2010 which will passed the expiry date afterJuly 2013. So we need test it again. Now we are all preparing it.