ISO 21109:2025

Overview

ISO 21109:2025 is an international standard developed by the International Organization for Standardization (ISO) that specifies a precise test method for determining the pH of nicotine pouches. Nicotine pouches are oral products containing nicotine, vegetable fiber bases, and flavorings but no tobacco leaf material. Accurate pH measurement is critical for understanding the proportion of non-protonated (free-base) nicotine available, which influences product behavior and user experience. This standard reflects an outcome of an extensive international interlaboratory study coordinated by CORESTA’s Tobacco and Tobacco Products Analytes Sub-Group in 2021, ensuring reliable reproducibility and repeatability across testing facilities worldwide.

Key Topics

• Scope: Establishes a standardized laboratory method for extracting an aqueous solution from nicotine pouches and measuring its pH using calibrated pH meters.
• Test Equipment: Requires common lab apparatus such as a pH meter with a combined electrode, orbital or magnetic stirrers, pipettes for accurate liquid measurement, closed extraction vessels, temperature measurement devices, and analytical balances.
• Reagents: Emphasizes using high-purity water (ISO 3696 grade 2 or better) and certified pH buffer solutions at points 4.00, 7.00, and 10.00.
• Procedure: Defines careful sample preparation by weighing approximately 2.0 g of pouch content, extraction with water, agitation, and immediate pH measurement while maintaining controlled testing temperatures between 20 °C and 25 °C.
• Calibration: Stresses proper pH-meter calibration before each measurement session with 2 or 3-point buffer solutions to ensure measurement accuracy.
• Data Quality: Provides reproducibility and repeatability criteria based on statistically analyzed results from multiple laboratories, with specified limits ensuring the method's precision.
• Reporting: Specifies comprehensive reporting requirements including sample identification, methodology, environmental conditions, and any deviations or factors that may affect results.

Applications

• Product Characterization: Enables manufacturers and quality control laboratories to accurately characterize nicotine pouches by assessing pH, which directly affects nicotine bioavailability and sensory attributes.
• Regulatory Compliance: Supports regulatory bodies by providing a harmonized method to verify product consistency and safety parameters linked to nicotine delivery.
• Research and Development: Assists researchers in developing new formulations by understanding how changes in pH impact nicotine release and consumer acceptability.
• Interlaboratory Consistency: Ensures consistent and comparable pH data across laboratories worldwide through a standardized approach, facilitating global trade and quality assurance.
• Quality Control: Integral for routine batch testing to monitor product stability and compliance with declared nicotine specifications.

Related Standards

• ISO 3696 - Laboratory water specifications and test methods, ensuring use of high purity water in pH testing.
• ISO 80000-9 - Defines the scientific concept and unit of pH.
• ISO 5725-2 - Provides the basic methodology for determining repeatability and reproducibility of standardized measurement methods.
• CORESTA Recommended Method No. 69 - Related tobacco product pH determination methodology that informed the development of this standard.

Keywords: ISO 21109, nicotine pouches, pH determination, test method, laboratory standard, nicotine product testing, CORESTA study, pH meter calibration, reproducibility, repeatability, quality control, tobacco product standards