White or pastel garments that arrive with yellow patches have often met phenolic yellowing. Phenolic antioxidants such as BHT, used in polyethylene film and other packaging, react with nitrogen oxides from polluted air and leave yellow marks on the fabric. The packing is the usual carrier, but finishes and trims can carry the same compounds.
Why did white garments arrive with yellow patches?
For white tops, mga damit, kaftans and scarves packed in polybags, the most likely cause is phenolic yellowing. Cotton Incorporated’s technical bulletin ISP-1002, Overview of Fabric Yellowing, describes how researchers traced storage yellowing of white and pastel fabrics to fabric wrapped in polyethylene film or mga bag. The bulletin states that “phenolic antioxidants, most notably butylated hyroxytoluene (BHT), blended into the polyethylene film as a protectant and preservative react with nitrogen dioxide from atmospheric pollution to form yellowing on the fabric surface.”
The testing company SGS describes the same reaction in its Safeguards bulletin 065/08. It says phenolic yellowing is caused by phenolic compounds in the presence of nitrogen oxides (NOx). It also says the problem shows up on white and pastel textiles and garments.
Where does the nitrogen dioxide come from? The Cotton Incorporated bulletin names oxides of nitrogen as the single biggest source of yellowing from air pollution. It lists lightning as a natural source. Man-made sources include petrol and diesel engines, gas- and oil-fired heating, and industrial processes.
Is it the fabric or the packing?
On white and pastel garments, it is most often the packing, but not always. SGS states that most of these yellowing problems are not due to the fibre or the textile finish. They come from phenolic antioxidants in packaging materials that migrate onto the textile.
The Cotton Incorporated bulletin widens the list of carriers. It reports phenolic antioxidants in:
- polyethylene wrap and bags, cardboard, brown paper and other packaging;
- fibre extrusion additives, fibre finishes, textile softeners, coning oils and knitting lubricants;
- foam paddings, interlinings, fabric adhesives and stitch lubricants.
So a white kaftan in a clean polybag can still yellow if its softener or interlining carries the antioxidant. The bulletin also warns that cationic softeners may intensify yellowing by storing phenolic compounds. The fabric side and the packing side both need checking.
What does phenolic yellowing look like on a garment?
On a white dress or top, it often appears as patches rather than an even tint. The Cotton Incorporated bulletin says: “This yellowing can be in patches and is normally reversible.” It adds that the yellowing often can be removed by an acidic scouring of the fabric or by exposing the fabric to direct sunlight.
The bulletin also notes that the problem was not uniform. Within one carton of fabric rolls, some rolls showed severe yellowing while others showed none.
Lighting matters when you judge the marks. The bulletin explains that incandescent light makes yellow look stronger, while simulated daylight shows less. It advises that buyer and seller agree on controlled, consistent viewing conditions, and that sunshine should never be the only light source for judging colour.
How is it different from other yellowing on white tops and dresses?
Phenolic yellowing on white mga blusa and dresses is a reaction on the fabric surface, and it is often reversible. Damage from a hot iron is a separate problem; see this post on pressing scorch and shine. Colour moving from one garment to another in transit is also separate; see this post on dye transfer in storage and transit.
| Yellowing type | Dahilan | Sign | Check |
|---|---|---|---|
| Phenolic yellowing | Phenolic antioxidants such as BHT in packaging, finishes or trims react with nitrogen dioxide (Cotton Incorporated; SGS) | Patches; normally reversible; may affect some rolls in a carton and not others (Cotton Incorporated) | ISO 105-X18, which assesses the potential of textile materials to phenolic yellowing (ISO; SGS) |
| Fibre degradation | Excessive heat, especially with high humidity; high ultraviolet exposure; long-term storage that ages the fibre (Cotton Incorporated) | In aged cotton fabric: yellowing with loss of breaking strength, lower moisture regain and lower dye uptake (Cotton Incorporated) | The bulletin warns that yellowing from degradation may mean the fabric cannot be restored (Cotton Incorporated) |
| Chemical finishes, such as softeners | Softeners yellow from high heat, long storage or incorrect formulation (Cotton Incorporated) | The fabric surface attracts oily dirt, which creates a tendency toward yellowing (Cotton Incorporated) | Use softeners without phenolic-based antioxidants, in minimum amounts (Cotton Incorporated) |
What does the ISO 105-X18 test tell a buyer about white scarves and kaftans?
ISO 105-X18 tells a buyer whether a fabric for white scarves or mga kaftan has the potential to yellow by the phenolic route. Its scope reads: “ISO 105-X18:2007 specifies a method intended for assessment of the potential to phenolic yellowing of textile materials.”
Its published summary states: “The method is specific to phenolic yellowing and does not cover the many other possible causes of yellow discolouration found on textile materials.” A pass does not rule out yellowing from heat, light or finishes.
SGS gives a brief outline of the method. Test specimens and a control fabric sit between test papers and glass plates. The stack is sealed in BHT-free polyethylene film and held in an oven for a set time at a set temperature. The specimens are then judged against the grey scale for assessing staining.
What can a buyer specify for white and pastel dresses and tops?
A buyer of white and pastel mga damit at mga blusa can specify both the packing and a test. The Cotton Incorporated bulletin recommends packaging, wrapping materials and boxes free from phenolic antioxidants where possible, and gas-impermeable wrapping films. It recommends good ventilation in storage areas and keeping internal-combustion vehicles out of warehouses. It also recommends a slightly acidic finished fabric, around pH six or below.
What to put in the spec / pagsubok
- Mga polybag, mga karton, dividers and tissue: free from phenolic antioxidants such as BHT.
- Wrapping film: gas-impermeable.
- Softeners and finishes: no phenolic-based antioxidants or preservatives; minimum softener.
- Trims such as interlinings and shoulder pads: free from phenolic compounds.
- Finished fabric pH: slightly acidic, around pH six or below.
- Test: ISO 105-X18 on the white or pastel fabric, to assess its potential to phenolic yellowing.
- Inspeksyon: an agreed, controlled light source for judging whiteness, not sunshine alone.
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