I-CHEM Certified® 400 Series products have all the features of the 300 Series and are also sterile. Available in NALGENE® wide mouth bottles that are gamma irradiated and certified for sterility in addition to EPA metals and water quality parameters.  Bottle and closure design guaranteeds bottles are leakproof. Heatshrink band on neck and closure ensures sterility and provides added assurance that closure is secure.