Work Item
ASTM WK72349

New Test Method for Determination of Microplastics Particle and Fiber Size, Distribution, Shape and Concentration in Waters with High to Low Suspended Solids Using a Dynamic Image Particle Size and Shape Analyzer.

1. Scope

This test method provides for the determination of microplastic particle and fiber size and shape characterization with the capacity to perform image analysis, foreign object detection, and number concentration in sample extracts containing particles between 5 and 100 microns. Light is transmitted through a flow cell containing particles in liquid medium. The particles create shadows as they pass through the field of vision of a camera thus producing a multitude of images. The images are then used to measure size, shape and concentration. The method requires a sample size as small as 50 L, enabling this method to be used as a complementary technique for microplastic particle and fiber polymer identification methods WK67565 (IR microscopy) and WK67788 (GCMS pyrolysis).


Microplastics; drinking water; wastewater; microplastic pollution measurement; microplastic pollution; microplastic contamination; microplastics in wastewater; influent; effluent; raw sewage; sampling procedures; identification procedures; collection procedures; sampling procedures; quantification procedures; sample preparation; all water matrices; high turbidity water; low turbidity water; suspended solids; calibration samples; reference samples; mass-based; count-based; proficiency samples; analytical quality assurance; quality assurance; quality control; microplastic size; microplastic shape; microplastics concentration; dynamic imaging; particle size and shape analyzer


Microplastic particles and fibers are now recognized as pervasive in the environment - including wastewater effluent, the ocean water column, sediments, animal tissue and even drinking water. This pervasiveness has led to product bans for small plastics, such as microbeads used in cosmetic products, to larger plastic items that can degrade into microplastics, such as bags and straws. In addition, there are new and planned requirements to monitor microplastics in the environment, wastewater effluent and in drinking water. Implementing monitoring programs requires reliable standardized methods and best practice guidelines. Such methods enable comparison of studies, and the ability to compare quantification among sources. Although the quantification and characterization of microplastics in samples has been occurring for more than a decade, the results are not necessarily reliable or comparable because neither standard field and laboratory methods for collection and identification nor the reference materials necessary for quality assurance yet exist.

The title and scope are in draft form and are under development within this ASTM Committee.


Developed by Subcommittee: D19.06

Committee: D19

Staff Manager: Brian Milewski

Work Item Status

Date Initiated: 03-21-2020

Technical Contact: William Lipps

Item: 001

Ballot: D19.06 (22-02)

Status: Will Reballot Item

Item: 003

Ballot: D19.06 (22-01)

Status: Will Reballot Item

Item: 007

Ballot: D19 (22-04)

Status: Negative Votes Need Resolution