Oxidation in Vaping – What It Is & How It Affects E-Liquid
Oxidation
Definition
Oxidation in vaping is the chemical reaction between oxygen, heat, and metal coil or e-liquid molecules. Over time, this process forms a thin oxide layer on stainless-steel, nichrome, or kanthal coils, altering flavour and resistance. In e-liquids, oxidation darkens colour, thickens viscosity, and can mute or deepen flavour notes. It is a natural, unavoidable occurrence that signals ageing components rather than a defect.
Technical Details
When a coil is heated above 150 °C, surface metal atoms lose electrons to airborne oxygen, creating metal-oxide films (Fe₂O₃ on kanthal, Cr₂O₃ on stainless-steel). This micro-layer increases electrical resistance by 0.05–0.2 Ω on typical 0.4 Ω builds, subtly shifting Ohm readings on an OLED screen. In open system tanks, nicotine reacts with oxygen to form cotinine and nitrosamines, darkening 3 mg freebase e-liquid from straw-yellow to amber within 30 days at 25 °C. VG oxidises faster than PG, raising viscosity by 10–20 % and reducing wicking speed through Cotton“>organic cotton.
Usage & Tips
- Dry-burn stainless-steel coils briefly at 10 W to remove oxide; avoid glowing red to prevent overheating protection cut-off.
- Store e-liquid in amber glass away from light and heat; use within 6 months for best flavour.
- If flavour becomes metallic, replace coil; if e-liquid tastes peppery, discard bottle.
- Keep nicotine salts refrigerated to slow oxidation.
History & Context
Early 2010 genesis atomisers used silica wicks that masked oxidation taste. The switch to organic cotton and sub-ohm vaping in 2014 made coil oxidation more noticeable, prompting manufacturers to pre-oxidise (anneal) coils for consistency and longer life.