pH Testing in Textiles: Why the Wrong pH Causes Skin Complaints and How to Fix It

Why pH Matters in Textiles

The human skin has a naturally acidic surface pH of 4.5–5.5, maintained by the acid mantle — a thin layer of sebum and perspiration that acts as a barrier against bacteria, fungi, and chemical irritants. When a textile article has a pH significantly outside this range, it disrupts the acid mantle on contact. Prolonged exposure to alkaline textiles (pH above 7.5) has been associated with skin dryness, itch, contact dermatitis, and increased susceptibility to skin infections. For infants, whose acid mantle is not fully developed, the risk is significantly higher — which is why baby textile limits are stricter than adult limits.

In Pakistani textile manufacturing, pH issues are almost always a processing problem, not a raw material problem. Natural fibres (cotton, wool) are inherently close to neutral pH. It is the dyeing, bleaching, mercerising, and finishing processes — all of which use strongly alkaline auxiliaries — that shift pH out of range. If the final washing and neutralisation steps are inadequate, the fabric retains residual alkali from these processes.

pH Limits by Standard

Test Method: ISO 3071

The standard method for determining pH of aqueous extract from textiles is ISO 3071:2006. The fabric sample is extracted in hot water at 60 ± 2°C for two hours. The extract is cooled and pH is measured with a calibrated glass electrode pH meter. Results are reported to one decimal place. The test is straightforward — the challenge is not in testing but in process control at the factory level to ensure consistent results.

pH Interactive: What Does Your Reading Mean?

Further Reading