The operational life of rental workwear is defined by the laundry, not the wear. A garment worn in a food processing plant, pharmaceutical facility, or logistics centre doesn't wash like consumer clothing — it goes through an industrial laundry process: high-temperature washing at 60–85°C, chlorine bleach treatment, commercial tumble drying, and often calendering or steam pressing. A zipper that performs adequately in domestic washing at 40°C may fail in this environment within the first laundry cycle.
What EN ISO 15797 Requires
EN ISO 15797 is the European standard for industrial washing and finishing processes for workwear. It defines test procedures that simulate industrial laundry conditions, enabling workwear components to be tested against the process they will actually face in service rather than the gentler domestic wash protocols.
The standard defines several test programmes corresponding to different wash temperatures and chemical profiles. The most commonly specified for rental workwear are:
Programme 6A: 75°C wash with both oxygen bleach and active chlorine bleach. This is the most demanding programme and is standard for white and light-coloured garments in food processing, pharmaceutical, and cleanroom environments. It is the programme that most aggressively attacks dyed tape, polymer components, and slider mechanism integrity.
Programme 4A: 60°C wash with oxygen bleach only. Standard for coloured workwear across most industrial rental categories. Significantly less aggressive on colour than 6A but substantially harder on components than domestic washing.
For rental workwear procurement, manufacturers or rental operators typically specify that components must demonstrate dimensional stability, colour retention, and mechanical function after 50 wash cycles minimum at the applicable programme. Some programmes specify 100 cycles as the baseline, particularly in pharmaceutical and food-grade categories.
Why Standard Apparel Zippers Fail in Industrial Laundry
Temperature Degradation
Domestic washing operates at 30–60°C. Industrial washing at 75–85°C exceeds the tolerance of components designed for consumer use. Nylon coil zipper tape can show shrinkage and dimensional distortion at sustained high temperatures. DWR coatings and waterproof laminates intended for outdoor garments — perfectly stable in domestic washing — may delaminate or blister at industrial wash temperatures.
Metal components withstand high temperatures significantly better than polymer ones. Stainless steel teeth and zinc alloy sliders remain dimensionally stable at 85°C. The component to verify specifically is the slider's auto-lock mechanism spring: spring steel behaviour at high temperature and pH extremes should be confirmed with the supplier before finalising specification for Programme 6A applications.
Chlorine Bleach Degradation
Active chlorine in Programme 6A attacks the dye on zipper tape, causing colour loss and discolouration visible after relatively few cycles. It also embrittles some polymer materials over repeated exposure.
For Programme 6A applications, specify:
- Polyester tape rather than nylon — polyester generally outperforms nylon in chlorine resistance at high temperatures
- Dyes with documented colour retention after EN ISO 15797 Programme 6A testing
- Metal hardware verified to resist corrosion and discolouration under chlorine exposure — stainless steel is the most resistant, zinc alloy is acceptable in most cases, standard brass is not appropriate for Programme 6A
Mechanical Stress from Commercial Processing
Industrial washing machines operate at higher mechanical intensity than domestic machines. The combination of large load, high temperature, and extended cycle times creates greater stress on the slider mechanism and the tape-to-tooth attachment than domestic washing.
The key failure mode to design against for industrial laundry is tooth detachment — individual teeth separating from the tape as the sewing thread fatigues under repeated mechanical and chemical stress. Specify a dense tooth pitch construction with a reinforced sewing line, and confirm with your supplier that the specification has been validated through the applicable EN ISO 15797 programme.
What Documentation to Request
For any zipper specification in rental workwear intended for industrial laundry, the minimum documentation requirements are:
Wash cycle test report: Demonstrating dimensional stability, colour retention, and mechanical function (slider operation, tooth integrity, pull-off force) after 50 cycles minimum at the applicable EN ISO 15797 programme. The report should state the programme and cycle count clearly.
Colorfastness declaration: ISO 105-C06 washing fastness, minimum grade 4. For Programme 6A, specify additional testing against active chlorine exposure at programme conditions.
Component material declaration: Tape fibre content and dye chemistry. Teeth material and alloy. Slider and hardware alloy specification. Spring material in the auto-lock mechanism.
REACH compliance: Declaration of conformity for workwear-relevant REACH restrictions — nickel (skin contact), AZO dyes in tape, phthalates in plastic components.
The Closed Zipper Rule
This practical point is consistently missed in rental workwear processes: all zippers must be closed before a garment enters the wash. An open zipper in a commercial washing machine can catch on other garments, causing tooth damage, tape distortion, and pull-off failures in a single cycle. For rental operations processing hundreds of garments per batch, one open zipper can damage multiple garments in the same load.
This instruction should appear in the garment's care documentation and be reinforced as a standing process step in the laundry operator's handling guide.
For FR workwear zipper options in metal and FR-treated constructions — relevant for rental workwear in protection-critical environments — see our fire protection zippers page. For stainless steel and high-durability metal zipper options suited to industrial laundry applications, see our metal zippers page.
We stock EN ISO 15797 wash-compliant zipper specifications for workwear producers. Wash durability test data is available per product and can be included in your supplier documentation for certification.
