Polyester textile manufacturing and quality assurance guide.
Ozone in air can react with some textile colour systems, producing colour change even without washing. Ozone fastness is not identical to sunlight fastness. ISO 105-G03:1993, reconfirmed in 2025, describes evaluation of textile colour resistance to atmospheric ozone under specified humidity and temperature conditions.
Underlying mechanism
Ozone is a reactive oxidant that can alter susceptible dyes. Exposure rate and the final shade change depend on dye chemistry, relative humidity, temperature and duration. The relevant ISO method includes conditions at ambient room temperature and moderate humidity as well as elevated-temperature, high-humidity conditions. Results should always state the tested exposure regime.
Factory analysis works best when it starts with a reference, reproducible measurements and the actual end-use condition. Do not assume one impressive reading establishes all fabric performance requirements.
What to measure and control
1. Selected ISO 105-G03 exposure condition and edition
Selected ISO 105-G03 exposure condition and edition. Record the observation against the sample or batch number, date of the experiment, equipment settings and test method. Hold other factors stable during a correction trial.
2. Temperature and relative humidity during testing
Temperature and relative humidity during testing. Record the observation against the sample or batch number, date of the experiment, equipment settings and test method. Hold other factors stable during a correction trial.
3. Ozone concentration and exposure control
Ozone concentration and exposure control. Record the observation against the sample or batch number, date of the experiment, equipment settings and test method. Hold other factors stable during a correction trial.
4. Shade-change grade on the relevant reference scale
Shade-change grade on the relevant reference scale. Record the observation against the sample or batch number, date of the experiment, equipment settings and test method. Hold other factors stable during a correction trial.
5. Dye recipe and finishing residues that may change response
Dye recipe and finishing residues that may change response. Record the observation against the sample or batch number, date of the experiment, equipment settings and test method. Hold other factors stable during a correction trial.
Recommended practical checks
- Step 1: Identify which garments or storage environments raise an ozone-fading risk. Capture raw measurements and note deviations from the agreed procedure.
- Step 2: Prepare reference and affected dyed polyester fabric specimens. Capture raw measurements and note deviations from the agreed procedure.
- Step 3: Use a qualified laboratory with controlled ozone exposure equipment. Capture raw measurements and note deviations from the agreed procedure.
- Step 4: Evaluate exposed versus unexposed regions under controlled light. Capture raw measurements and note deviations from the agreed procedure.
- Step 5: Review shade and dye formulation if resistance fails buyer criteria. Capture raw measurements and note deviations from the agreed procedure.
Formula or interpretation
Colour-fastness-to-ozone grading describes observed colour change under defined exposure conditions; it does not predict a fixed outdoor lifetime or replace lightfastness and washing tests.
Common failure pattern
A shade that remains stable in water and light tests may still change after ozone exposure because different degradation mechanisms are involved.
How bulk buyers should specify this property
For susceptible colours and export programs, request the exact ozone test condition rather than an unspecified 'colourfastness pass' statement.
- Confirm yarn/fabric composition and end-use.
- Specify test state, method, units and sampling locations.
- Compare approved and questioned specimens under equivalent conditions.
- Record full result ranges and visible failure locations.
- Include relevant wash, wear or storage ageing.
- Verify a corrective change before signing off bulk orders.
Frequently asked questions
Is ozone colourfastness the same as lightfastness?
No; the chemical agents and exposures differ.
Does humidity matter?
Yes; specify the ISO method condition including humidity and temperature.
Is ISO 105-G03 still current?
The ISO record says the 1993 edition was reconfirmed in 2025.
Related reading
Educational guidance. Apply current official test methods, safety protocols and buyer-approved acceptance criteria before factory use.
