Operating range from 0…+220 °C. Silicone fluids are non-toxic and compatible with many materials. Do not use with silicone tubing! Refer to product datasheet and SDS for additional information. At higher temperatures (>150 °C) silicone fluids will 'smoke' - this is a normal property of silicone fluids and will not pose a danger. Thermal C20S contains a stabilizer and will darken over time with extended high temperature operation - this is normal. We recommend monitoring fluid health on a regular basis when operating the fluid near the upper temperature limit on a regular basis. Fluid should be changed regularly to circumvent thickening or polymerization. Dispose according to local, state and federal waste guidelines.