Endothermic atmosphere is prepared by reacting a mixture of hydrocarbon gas, typically methane or. propane and air, metered in a proportion such that there is just enough oxygen to form carbon monoxide. and hydrogen without excess carbon dioxide or water vapor.
But for your everyday run-of-the-mill deep conditioner, it should begin to work instantly, and reach maximum capacity at around the 20 or 30 minute mark. If your deep conditioner doesn't work after 30 minutes, it's time to ditch it for one that's more effective.
How Long to Leave Hair Color On. How long you should leave hair color on depends on the directions from the manufacturer, but usually it is about 30 minutes. Make sure you know how long to leave hair color on with tips from a professional hair stylist in this free video on hair highlighting. Part of the Video Series: Hair Highlighting.