How to read a developer bottle

Volume and percentage explained

Hydrogen peroxide strength is marked in two ways on our mixing bench bottles. Volume refers to the amount of oxygen gas released by one measure of liquid during the reaction. The percentage tells you the actual weight of pure hydrogen peroxide in that same liquid. A 20 vol label corresponds to 6 percent concentration, while a 30 vol label corresponds to 9 percent concentration.

Choosing between our two strengths

Different lightening steps require different peroxide concentrations. We offer developer at 20 vol (6%) and at 30 vol (9%) to pair with our bleaching powder or creme lightener. Reaching for 20 vol provides moderate lift with less strain on the fiber. Reaching for 30 vol provides more lift, which is why it is chosen when darker hair needs extra lightening.

Higher strength is not a shortcut

Using 30 vol instead of 20 vol does not produce a superior finish on every head. Stronger peroxide accelerates the oxidation process, but it also increases the risk of rough texture and breakage if left on fine or fragile strands. Higher concentration creates more chemical lift, not a better condition for the hair fiber.

Following the printed directions

Exact mixing ratios and processing times belong on the insert inside the box. Ratios depend on whether you combine the liquid with our 45 g powder, 100 g powder, or 150 g creme lightener. Web summaries cannot replace the measured proportions and safety instructions printed in the packaging.

Storage and shelf life after opening

Exposure to air and light degrades hydrogen peroxide over time. Once the seal is broken, the chemical slowly breaks down into water and oxygen gas, losing its lifting strength. Keeping the cap tight and storing the bottle in a cool place slows this loss, but old developer will not lift as expected.