A drinking-water method using microscopy and Raman spectroscopy.
Source details
California State Water Resources Control Board and SCCWRP. Official document. 2022.
Findings
Raman identification and microscopy provide complementary composition, size and count information; contamination controls remain necessary.
The method states a lowest reliably detected particle size of 20 µm. That is a method-scope value, not a safe exposure threshold.
Methods and scope
Revised May 27, 2022. PDF pp. 2–3 §§1–2: treated-water scope, filtration/sieving, microscopy, Raman chemical identification and blank/control requirements.
What this source can support
An official laboratory method for treated drinking water.
Its validated particle-size coverage must not be applied to unrelated food, dust, tissue or textile matrices without validation.
Related evidence
Plastic food storage · Baby wipes · Infant feeding bottles · Tea bags · Bottled water · Tap water · Cutting boards · Cosmetics and personal care · Household dust and air · Textiles · How microplastics are measured · Regulatory and agency context
Reported values and source locations
| Reported value | Measurement basis | Conditions and size context | Original document location |
|---|---|---|---|
| 20 µm | Stated lowest reliably detected particle size in this method | Treated drinking water under the supplied revised May 27, 2022 method Stated lowest reliably detected size 20 µm; method upper size 5000 µm | PDF p. 2 §§1.1 and 1.3 |
Source provenance
Primary PDF SHA-256: 5a6c89659a697ed1a22f0c3c070e1906ba38f3cbcd3f72b5dd0303a80760a9d5
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