Interpretation of ISO 6330:2021 “Textiles—Home washing and drying procedures for testing”

August 12, 2026
fyi-tester
standard analysis

The international standard ISO 6330:2021 “Textiles—Home washing and drying procedures for testing” (hereinafter referred to as the “new standard”) was published and implemented in November 2021. This standard was jointly developed by ISO/TC 38/SC2 and CEN/TC 248 under the technical cooperation agreement between ISO and CEN (Vienna Agreement). The fourth edition cancels and replaces the third edition ISO 6330:2012 “Textiles—Home washing and drying procedures for testing” (hereinafter referred to as the “old standard”). This standard is not only an important basis for dimensional stability measurement, but also a basis for pretreatment for assessing the functionality and physical properties of textiles. Compared with the old standard, the new standard mainly revises the terminology, reference detergents, test water, accompanying items, equipment, washing procedures, drying procedures, and report content, making the new standard more in line with consumers’ daily washing habits and more procedural and standardized. This article uses a comparative analysis of the new and old standards to interpret the revisions and proposes suggestions for the implementation of the new standard.

Terminology

The number of terms and definitions has increased from 10 in the old standard to 11. The term “humidity control device” in the old standard has been renamed “rotary humidity sensor,” but the definition remains the same, and other terms are unchanged. The newly added term is “wash load,” which refers to the material to be washed, consisting of a mixture of accompanying items and the test sample.

Reference Detergent

Information Update

The new standard clarifies relevant terms: Annex H uses “brightener,” Annexes I and L use “optical whitener,” and Annex K uses “optical brightener.” Although the terminology differs, they all refer to “optical brightener” in this standard. In addition to the six detergents in the old standard, the new standard adds one new detergent, Reference Detergent 7. Reference Detergent 7 is a liquid detergent for wool/silk materials, suitable for mild or gentle washing processes. This detergent is generally suitable for materials labeled as gentle or hand-washable. Reference Detergent 7 was developed for use in IEC 60456, “Test methods for performance of household washing machines,” and its nominal composition is specified in Annex M.

Composition

Appendices H-M of the new standard specify the nominal composition of reference detergents 1, 2, 3, 4, 6, and 7, respectively. The composition and tolerances of reference detergent 1 have been modified. Reference detergents 2, 3, and 6, based on the existing formulations containing sodium perborate tetrahydrate in the old standard, have each added a new formulation containing sodium percarbonate. The composition and tolerances of reference detergent 4 remain unchanged. The component information for reference detergent 5 has been deleted. The composition and tolerances of reference detergent 7 have been added.

It should be noted that reference detergents 2, 3, or 6 consist of three independent components and should be thoroughly mixed according to the specified proportions before use. Based on the old standard’s mixing ratio of “77% powder detergent, 20% sodium perborate tetrahydrate, and 3% bleaching surfactant,” the new standard adds a new mixing ratio using sodium percarbonate instead of sodium perborate tetrahydrate: “82% powder detergent, 15% sodium percarbonate, and 3% bleaching surfactant.”

Dosage

For Type A standard washing machines, the recommended detergent dosage of 7 has been added; for Type B standard washing machines, the recommended detergent dosage of 5 has been removed; and for Type C standard washing machines, the type and dosage of recommended detergent remain unchanged. The new standard stipulates that recommended detergent 7 can be used for lightweight items or wool.

Accompanying items and washing load

Accompanying items

(1) Types

The new standard adds “accompanying fabrics related to other product performance specifications” to the existing three types of accompanying laundry items (Type I, Type II, and Type III).

(2) Specifications

The new standard separates the production specifications and usage specifications of accompanying laundry items. The old standard’s “Composition and Specifications of Accompanying Laundry Items” table is split into two tables: “Composition and Specifications of Greige Fabric” and “Composition and Specifications of Accompanying Laundry Items.” The latter includes single-piece size, single-piece weight, and shrinkage rate.

The new standard standard unifies the representation of single yarn linear density for accompanying laundry items, using metric Tex units, and adds tolerances. While no requirements are made for the single yarn linear density of Type III accompanying laundry items, the new standard adds a note stating, “Yarn linear density is not a key parameter; structure and fabric weight per square meter are key influencing factors,” making the expression more rigorous. The tolerance representation method for single-piece size of accompanying laundry items is standardized. The specifications of the accompanying laundry fabric remain substantially unchanged.

(3) Selection Method

The new standard has changed the selection method for accompanying garments, mainly in the following aspects:

Clearly quantifying the fiber content of the product;
For products containing less than 51% cellulose fiber, the old standard used Type I cotton accompanying garments, while the new standard modifies this to use Type II polyester/cotton accompanying garments or Type III polyester accompanying garments;
For products containing 51% or more synthetic fiber, only Type III polyester accompanying garments are specified. The old standard allowed for the use of Type II polyester/cotton accompanying garments or Type III polyester accompanying garments;
With the consent of the relevant parties, accompanying garments related to the performance specifications of other products can be used, and the substitute accompanying garment should be noted in the test report. The new standard fills the gap in the old standard where accompanying garments could not be selected for products other than cellulose fiber products, synthetic fiber products, and blended products, such as wool and silk products. The new standard provides a clearer and more complete selection method for accompanying garments.

Washing Load

Both the old and new standards specify a uniform total washing load mass for all types of standard washing machines. The new standard expands the tolerance range for total washing load, changing it from (2.0±0.1) kg in the old standard to (2.0±0.2) kg. Correspondingly, when testing a whole garment, the total washing load mass to be reported has changed from “greater than 2.1 kg” in the old standard to “greater than 2.2 kg”.

Equipment

Automatic Washing Machines

The new standard adds the dimension of the inner drum lifting plate’s side side length (laboratory calibration) of “(60±1) mm” to the specifications of Type A standard washing machines. It also adds two measurement diagrams for the height and side side length of the inner drum lifting plate. The specifications for Type B standard washing machines have been removed from the new standard. The specifications for Type C standard washing machines are the same in both the old and new standards.

Rotary Dryers

The new standard modifies the volume, diameter, and rated capacity of the rotary dryer drum. The upper limits for the drum volume and diameter of Type A1 and A2 rotary dryers have increased, while the lower limits for the drum volume and diameter of Type A3 rotary dryers have decreased.

Washing program

Type A Standard Washing Machines

The new standard for Type A standard washing machines increases the number of washing programs from 13 to 16, based on the old standard. The new standard adds three new programs: 3H, 3HD, and 4HD. The other 13 programs remain the same. Programs 3H, 4H, 3HD, and 4HD each include one wash cycle and two rinse cycles. The difference between programs 3H and 4H, and between programs 3HD and 4HD, lies in the washing temperature: 3H and 3HD are (30±3) ℃, and 4H and 4HD are (40±3) ℃. The difference between programs 3HD and 3H, and between programs 4HD and 4H, lies in the final spin-drying time: 3HD and 4HD are 20 seconds, and 3H and 4H are 120 seconds.

The new standard modifies the annotations related to the washing programs for Type A standard washing machines. The annotations now include an explanation for HD, which stands for “draining from the washing machine without spin-drying.” The annotations for agitation modes N, M, G, and H have been revised. “High-speed rotation” is now added after normal agitation (N), and “low-speed rotation” is added after gentle agitation (M), mild agitation (G), and simulated hand wash (H). The annotation for the spin-drying time during the third rinse in programs 6M, 5M, 4M, 3M, and 3G has been changed from “short spin-drying or drip-drying” in the old standard to “short spin-drying,” removing “drip-drying.” The annotation “drip-drying” has been added after the agitation mode “mild” in the newly added 3HD and 4HD programs, meaning that “drip-drying” only applies to the 3HD and 4HD programs in the new standard, corresponding to the shorter spin-drying time (20 seconds) in these two programs.

Type B Standard Washing Machine

The 11 washing programs of the old Type B standard washing machine have been removed and replaced with 12 new washing programs. These 12 washing programs are composed of combinations of three product types and four temperatures. The parameters for Type B standard washing machines are defined by AATCC and are part of AATCC LP1, and are basically consistent with the parameters in AATCC.

Type C Standard Washing Machines

The washing parameters and washing programs for Type C standard washing machines remain unchanged between the old and new standards.

Drying Procedures

The new standard retains the six drying methods, but modifies the classification. The old standard divided drying methods into two main categories: air drying and tumble drying. The new standard divides them into three categories: air drying, flatbed drying, and tumble drying. Flatbed drying has been removed from the air drying category and is now a separate category. Flatbed drying uses a flatbed iron at suitable temperature and pressure to achieve drying, not simply air drying, making its removal reasonable.

The new standard moves the instruction “After the selected washing program is completed, immediately remove the sample and select a drying program from A to F” from the “Air Drying” clause to the general rules of the drying program, resulting in a more logical editorial structure.

The new standard adds the instruction “Use a 3HD or 4HD washing program to perform drip drying (e.g., without spin-drying)” to both the hanging drip-drying and flat drip-drying programs. This aligns with the note regarding “drip drying” in the Type A standard washing machine washing program table in Appendix B.

In the flat-lay drip-drying procedure, a note has been added stating that “for subsequent testing, drying can be carried out under conditioning conditions conforming to ISO 139.”

In the rotary drying procedure, the description of the dryer exhaust temperature specifications has been revised from “Ensure the rotary exhaust temperature is at least 40°C, and at most 80°C for normal fabrics and 60°C for lightweight fabrics” to “Ensure the rotary exhaust temperature is at least 40°C, at most 80°C for normal temperatures, and at least 60°C for low temperatures,” eliminating the previous specification for maximum exhaust temperature based on fabric type. Regarding the difference between the final moisture content and the conditioning moisture content in the definition of over-drying, in addition to the old standard for synthetic fiber textiles and cellulosic fiber textiles, a new provision has been added stating that “For textiles made from other fibers and blended fabrics, the final moisture content can be referenced from appropriate resources,” addressing the shortcomings of the original textile composition classification. Annex O of the new standard specifies the method for determining the drying time of the rotary dryer. Given that the estimated drying time may vary depending on the type of laundry, a new provision has been added stating that “For both normal and low temperatures, the drying time needs to be determined for each type of laundry.” In addition, the calculation formulas for drying time and drying endpoint have been revised, changing from textual representation to letter symbols for greater clarity.

Report Content

The test report includes some adjustments. New additions include the test date, conditioning atmospheric conditions, temperature and pressure of the flatbed press (if used), fluorescent whitening agents, sodium perborate or percarbonate (if such detergents are used), other accompanying items (not specified in this standard), and other abnormal phenomena observed during the test. The total air-dried mass of the sample and accompanying items has been removed. The new standard further improves the information content of the test report, making it more comprehensive.

References

The new standard adds AATCC M1 and AATCC LP1 to the references, and removes AATCC 1993, AATCC 2003, and ISO 6330:2000.

Conclusion

(1) Through comparative analysis of the old and new standards, it was found that the new standard has revised aspects such as terminology, reference detergents, test water, accompanying items, equipment, washing procedures, drying procedures, and report content. The main technical changes are as follows: A definition of washing load has been added; Reference Detergent 7 has been added, and a new set of formulations containing sodium percarbonate has been added to Reference Detergents 2, 3, and 6; the formulation of Reference Detergent 1 has been modified, and the actual content of Reference Detergent 5 has been deleted; the hardness and inlet temperature of the test water have been adjusted; the method for selecting accompanying items based on product composition has been modified and refined, instructions for using other accompanying items have been added, and the method for representing accompanying item specifications has been standardized; the side length dimension of the inner drum lift plate of the Type A standard washing machine has been added (for laboratory calibration), the specification parameters of the Type B standard washing machine have been deleted, and the parameters of the tumble dryer have been modified; three washing programs, 3H, 3HD, and 4HD, have been added to the Type A standard washing machine, and instructions for using the 3HD or 4HD washing program to perform hanging drip drying or flat drip drying programs have been added; the washing programs of the Type B standard washing machine have been modified to be consistent with AATCC; the tumble dryer program and report content have been modified and improved, etc. In addition, there are other editorial modifications and adjustments. The revised standard is more comprehensive, with a more reasonable structure, better suited to consumers’ daily washing needs, and more procedural and standardized in operation.

(2) The new standard also has shortcomings. For example, clause 6.2.3 of the standard stipulates that the water temperature at the inlet of the standard washing machine “does not exceed 25 ℃,” while the water supply temperature in the parameter table of the Type A standard washing machine is “(20±5) ℃” (this is the requirement of the old standard), creating a contradiction. This should be noted when implementing the standard.

(3) It is recommended that relevant enterprises and testing institutions thoroughly understand the new standard, update their testing equipment in a timely manner, and strictly conduct tests according to the standard to ensure the accuracy of the test results.

Reference: Printing and dyeing (2022 No.5)— “Interpretation of ISO 6330:2021 Textiles—Home washing and drying procedures for testing” If any copyright infringement is detected, please contact us.