TOC/VOC EPA Septa Vials, Amber & Clear - Thermal Scientific. I-Chem® offers both clear and amber borosilicate glass vials available in three sizes with the standard, 0.125 in. thick, I-Chem® blue, PTFE/silicone septa in an open-top 24-414 polypropylene cap. Amber vials should be used for light sensitive samples.