GB/T 35957-2018 in English

Interpretation of GB/T 35957—2018 National Standard of the People's Republic of China

Determination of Cesium-137 and Cesium-134, Prohibited Substances in Cosmetics - Y-Spectrometry

Background and Significance of Standard Formulation

This standard was drafted in accordance with GB/T1.1—2009 rules, proposed by the China Light Industry Federation, and managed by the National Technical Committee for Standardization of Flavors, Fragrances and Cosmetics. The formulation of the standard fills the gap in the field of radionuclide detection methods in cosmetics in my country and provides important technical support for ensuring the safety of cosmetics.

Scope of application of the standard

This standard is applicable to the determination of Cesium-137 and Cesium-134 in powder, cream, lotion and liquid cosmetics, with a detection limit of $10~\mathrm{Bq/kg}$.

Comparative Analysis of Technical Methods

Instrument and Equipment Specifications

Spectrometer is the core equipment of this standard and must meet the following requirements:
- Coaxial high-purity germanium detector: The $1.3325~\mathrm{keV}$ $\gamma$ ray energy resolution of cobalt-60 is less than $3~\mathrm{keV}$, and the relative efficiency is higher than $15\%$.
- Shield: The equivalent lead equivalent is not less than $10~\mathrm{{cm}}$, and it is lined with multiple layers of heavy metal materials.
- The $\gamma$ spectrometer integrated background should be less than 2.5 counts/second.

Standard Implementation Recommendations