【国外标准】 Standard Practice for Development of Microplastic Reference Samples for Calibration and Proficiency Evaluation in All Types of Water Matrices with High to Low Levels of Suspended Solids

5.1 These procedures can be used to generate microplastic particles as a simulation of microplastic particles found in the natural environment. Suitable uses may include evaluation of microplastic detection and imaging methods. Use of reference samples will support estimation of ambient and flux concentrations in drinking water, wastewater and natural environments, investigations of microplastic particle degradation, and ingestion of microplastics by animals in the contexts of food safety and human health risk assessment.1.1 This practice describes manufacturing methods to create microplastic particles from pellets of common polymers and the preparation of microplastic reference samples for calibration and proficiency evaluation of microplastic collection practices, preparation practices, and identification methods.1.2 This practice does not describe methods for controlling or characterizing the shapes of particles. The procedures have been observed to yield irregularly shaped particles, the use of which in many cases will serve to remove the analytical bias inherent with using distinctive manufactured spherical beads. Other procedures should be used if spheres or elongated fibers are desired.1.3 This practice does not describe handling procedures for waste generated when executing the procedures described herein. It is the responsibility of the user of this practice to follow applicable laws and regulations when manufacturing and disposing of microplastic particles, and to establish appropriate procedures to minimize the amount of waste generated.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.