Available in clear or amber borosilicate glass. Assembled with the solid top PTFE-Lined closures. Available in standard, precleaned or precleaned/certified in accordance with recommended E.P.A. Protocol. Class 1: (Standard) Containers are assembled with liner and closure without washing treatment. Class 2: (Precleaned) Containers are processed according to EPA recommended wash procedures. Washed with laboratory grade biodegradable, non-phosphate detergent, rinsed with ASTM Type I De-ionized water, over dried and assembled in a contaminate-free environment. The exterior of each case is labeled with a lot number. Each case contains a copy of wash "Standard Operating Procedure". Class 3: (Precleaned & Certified) Containers are processed according to EPA recommended wash procedures. Washed with laboratory grade biodegradable, non-phosphate detergent, rinsed with ASTM Type I De-ionized water, oven dried and assembled in a contaminate-free environment. The exterior of each case is labeled with a lot number. Each case contains a "Certificate of Analysis". An independent laboratory is used to certify the container's cleanliness, assuring impartial results.