Overview
EN ISO 23674:2022 - Cosmetics - Analytical methods - Direct determination of traces of mercury in cosmetics by thermal decomposition and atomic absorption spectrometry (mercury analyser) - specifies a laboratory procedure for quantifying total mercury (inorganic + organic) in finished cosmetic products. Adopted by CEN as EN ISO 23674:2022, the method enables direct solid analysis with no prior chemical digestion, using a thermal decomposition mercury analyser and atomic absorption detection.
Key topics and technical requirements
- Principle: Samples are thermally decomposed (combusted/ashed) in an oxygen flow; combustion gases pass through a hot catalyst, mercury vapour is trapped on a gold amalgamator and released by rapid heating. Detection is by atomic absorption at 253.7 nm.
- Temperature ranges: Typical combustion between 650 °C and 900 °C, catalyst around 615 °C, amalgamator release at 800–900 °C (as specified by the standard).
- Sample types: Valid for solid and liquid cosmetic samples; supports direct weighing of solids for analysis.
- Calibration: Covers both liquid and solid calibration standards and aims for a wide dynamic range using multiple measurement cell lengths when available.
- Quality control: Requires analysis blanks, quality control samples and replicates to monitor accuracy and precision. The standard discusses validation range vs validated range and method performance assessment (accuracy profile methodology is included in an informative annex).
- Reagents & materials: Minimal reagents (e.g., Grade 1 water per ISO 3696) are referenced; safety warnings and instrument/operational requirements are provided.
- Documentation: Specifies required elements for test reports and performance validation.
Applications and who uses it
- Cosmetic manufacturers for routine quality control and release testing to ensure products meet regulatory limits for mercury.
- Control laboratories and contract testing labs performing trace contaminant analysis in toiletries and personal care products.
- Regulatory agencies and market surveillance bodies verifying compliance with safety standards and consumer protection requirements.
- Product safety and R&D teams assessing ingredient sourcing and formulation changes for mercury contamination risk.
This method is especially valuable when rapid, digestion-free analysis is needed and where total mercury (any species) must be quantified directly in finished products.
Related standards
- ISO 23821 - a related method developed in parallel (interlaboratory comparison performed).
- ISO 3696 - specification for laboratory water used in the method.
- EN adoption: EN ISO 23674:2022 (CEN endorsement).
Keywords: EN ISO 23674:2022, ISO 23674, mercury in cosmetics, mercury analyser, thermal decomposition atomic absorption, trace mercury determination, cosmetics analytical methods.
