FRIO-Temp® Certified Precision Liquid-In-Glass Verification ThermometersFRIO Temp Certified Precision Liquid In Glass Verification Thermometers FRIO Temp verification thermometers for sample temperature measurement within Freezers, Refrigerators, Incubators or Ovens without introducing contamination. These thermometers are filled with environmentally safe non toxic, non hazardous, biodegradable Enviro Safe liquid EnviroKleen certified by ChemTel, an independent laboratory (except H B Catalog No. 20630 Organic liquid