ISO 21255:2018

Overview

ISO 21255:2018 establishes international standards for the storage and transportation of ultrafine bubble dispersions (UFBD) in water, providing essential guidelines to maintain the quality and stability of these dispersions. Ultrafine bubbles-also known as nanobubbles-have unique properties that make them valuable across various industries, including agriculture, semiconductor manufacturing, water treatment, and surface cleaning.

This standard specifies the necessary procedures, equipment, and environmental conditions required to preserve critical characteristics of the ultrafine bubbles, such as size and number concentration. By ensuring integrity during storage and transport, ISO 21255:2018 supports the expansion of fine bubble technology applications beyond on-site generation and use.

Key Topics

• Ultrafine Bubble Dispersion (UFBD): Defined as liquid containing ultrafine bubbles in water, requiring specific handling to preserve bubble stability.
• Storage Substances: Requirements emphasize using grade 1, 2, or 3 water (per ISO 3696) free from chemically active or bacterial contaminants that could alter UFBD properties.
• Containers and Filling Procedures:
  • Use rigid containers to minimize contact with air and mechanical disturbances.
  • Recommended container material is borosilicate glass 3.3 (ISO 3585) for its stability and inertness.
  • Interfaces should use low gas-permeable flexible materials like poly(isobutylene-isoprene) (IIR) to accommodate pressure changes without bubble deterioration.
  • Ensure sterilization (heat or UV) to avoid biological contamination.
• Storage Conditions:
  • Maintain temperature between 5 °C and 35 °C; avoid freezing (<0 °C) that causes bubble extinction.
  • Protect from direct sunlight and vibrations.
  • Consistent environmental conditions prevent degradation of bubbles.
• Transportation Requirements:
  • Similar temperature range applies (5 °C to 35 °C), with atmospheric pressure between 750 hPa and 1050 hPa.
  • Minimize vibrations and shocks; allowable acceleration below 100 m/s², with limited exceptions.
  • Use courier or specialized “fragile” transportation services to reduce risks.
• Record Keeping: Documenting storage and transportation parameters (dates, container details, environmental conditions) is mandatory to ensure traceability and quality control.

Practical Applications

ISO 21255:2018 provides a framework that supports industries requiring reliable supply chains for ultrafine bubble dispersions. Key applications include:

• Agricultural Enhancement: Transporting ultrafine bubbles for irrigation and plant growth stimulation without compromising bubble stability.
• Semiconductor Manufacturing: Safe handling of ultrafine bubble dispersions used in delicate processes like wafer separation.
• Water Treatment and Purification: Enabling off-site generation and distribution of ultrafine bubble water for advanced cleaning and pollution control.
• Surface Cleaning Solutions: Supplying stable ultrafine bubble formulations for removing oil, stains, and contaminants on infrastructure.

By standardizing storage and transport protocols, organizations can expand the deployment of ultrafine bubble technology beyond generation sites, enabling broad-scale commercial use and industrial integration.

Related Standards

ISO 21255:2018 references several complementary standards critical to its context:

• ISO 20480-1: Defines terminology and general principles for fine bubble technology and measurement techniques.
• ISO 3696: Specifies water quality classification for analytical laboratory use, relevant for water diluents in UFBD.
• ISO 3585: Covers properties of borosilicate glass 3.3 used in containers.
• ISO 4796-1: Describes laboratory glass screw-neck bottles suitable for UFBD handling.
• ISO/IEC Guide 98-1: Addresses uncertainty in measurement, ensuring precise quality assessment.

Compliance with these interconnected standards enhances the overall quality and reliability of ultrafine bubble technology applications.

Keywords: ISO 21255, ultrafine bubble dispersion, nanobubbles, fine bubble technology, UFBD storage, UFBD transportation, bubble stability, borosilicate glass container, water diluent, fine bubble standards, industrial ultrafine bubbles, bubble number concentration, bubble size integrity.