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ISO 25518:2021 – Single-Use Rubber Gloves for General Applications
Specification requirements, testing methods and quality control for disposable rubber gloves
Dimensional and Physical Requirements
ISO 25518:2021 specifies the physical requirements, sampling methods, and testing procedures for single-use rubber gloves made from natural rubber latex, synthetic rubber latex, or rubber solution. This standard applies to gloves intended for general applications, explicitly excluding medical-purpose gloves which are covered by separate standards such as ISO 10282 and ASTM D3578.
The distinction between general-purpose and medical gloves is critical. ISO 25518 gloves are designed for applications such as food handling, cleaning, industrial light-duty work, and laboratory use where barrier protection is needed but not at surgical levels.
Gloves are manufactured in five sizes: Extra Small (XS), Small (S), Medium (M), Large (L), and Extra Large (XL). The standard specifies both width and minimum length requirements. Width is measured at the midpoint between the base of the index finger and the base of the thumb, while length is measured from the tip of the middle finger to the cuff end, with the glove mounted on a mandrel with a 5 mm tip radius.
| Size | Width W (mm) | Tolerance (mm) | Minimum Length L (mm) |
|---|---|---|---|
| Extra Small (XS) | ≤ 80 | — | 220 |
| Small (S) | 80 ± 10 | ±10 | 220 |
| Medium (M) | 95 ± 10 | ±10 | 230 |
| Large (L) | 110 ± 10 | ±10 | 230 |
| Extra Large (XL) | ≥ 110 | — | 230 |
Tensile Performance and Accelerated Ageing
Tensile properties are measured according to ISO 37 using type 2 dumb-bell test pieces. Three test pieces are taken from each glove (from the palm or back), and the median value is used as the test result. The standard specifies minimum requirements for both force at break and elongation at break, tested before and after accelerated ageing.
| Property | Requirement |
|---|---|
| Minimum force at break before accelerated ageing | 7.0 N |
| Minimum elongation at break before accelerated ageing | 500% |
| Minimum force at break after accelerated ageing | 6.0 N |
| Minimum elongation at break after accelerated ageing | 400% |
Accelerated ageing is conducted in accordance with ISO 188. The standard provides two alternative ageing conditions: 70°C ± 2°C for 168 h ± 2 h, or 100°C ± 2°C for 22 h. Test pieces may be prepared by either ageing whole gloves and then cutting test pieces, or by cutting test pieces from unaged gloves and then ageing the test pieces. This flexibility allows laboratories to choose the most practical approach based on their equipment.
For gloves older than 6 months from the date of manufacture, accelerated ageing is not required and only the post-ageing tensile values (6.0 N / 400%) need to be met. The 6-month period begins on the first day of the month immediately after manufacture. This provision recognizes that natural rubber undergoes age-related changes that affect baseline tensile properties.
Watertightness Testing and Quality Control
The watertightness test (Annex A) is a critical quality assessment method. The apparatus consists of a circular hollow mandrel with a minimum external diameter of 60 mm, a holding device, and a graduated cylinder. The glove is attached to the mandrel and filled with 1000 cm³ ± 50 cm³ of water at a maximum temperature of 36°C. Any leaks are noted immediately, and a second observation is made 2 to 4 minutes after filling.
The watertightness test is particularly revealing of manufacturing quality. Pin-hole defects, thin spots, and material inconsistencies are readily detected. This test serves as an effective process control tool for glove manufacturers, complementing tensile testing by focusing on barrier integrity rather than mechanical strength.
Sampling and inspection follow ISO 2859-1 procedures. The standard specifies inspection levels and acceptance quality limits (AQLs) for three categories of characteristics: physical dimensions (S-2, AQL 6.5), watertightness (S-4, AQL 4.0), and tensile properties (S-2, AQL 6.5). When lot size cannot be determined, a lot of 35,001 to 150,000 pieces is assumed for sampling purposes.
The watertightness AQL of 4.0 means that up to 4% of gloves in a lot may have leakage defects while still meeting the standard. For applications requiring higher barrier reliability, users should specify tighter AQLs in their procurement agreements or consider medical-grade gloves which typically have AQLs of 1.5 or lower for pinholes.
Labelling requirements include the manufacturer name or trademark, material type, surface finish (textured/smooth, powdered/powder-free), size designation, lot number, date of manufacture, approximate quantity, storage instructions, and the statement “NOT FOR MEDICAL OR INDUSTRIAL USE.” Powdered gloves have a maximum powder limit of 15 mg/dm², while powder-free gloves have a maximum residue limit of 2.0 mg per glove.
Q1: What is the difference between ISO 25518 and medical glove standards?
ISO 25518 covers general-purpose gloves with less stringent AQLs for pinholes (4.0 vs. 1.5 or lower for medical gloves) and does not require viral penetration testing or biocompatibility assessment required for medical devices.
ISO 25518 covers general-purpose gloves with less stringent AQLs for pinholes (4.0 vs. 1.5 or lower for medical gloves) and does not require viral penetration testing or biocompatibility assessment required for medical devices.
Q2: How should gloves be stored to maintain their properties?
Gloves should be stored in a cool, dry place away from direct sunlight, ozone sources, and heat. Recommended storage temperature is below 30°C. Proper storage prevents premature ageing and degradation of tensile properties.
Gloves should be stored in a cool, dry place away from direct sunlight, ozone sources, and heat. Recommended storage temperature is below 30°C. Proper storage prevents premature ageing and degradation of tensile properties.
Q3: What does the “6-month” rule for accelerated ageing mean in practice?
Gloves tested more than 6 months after manufacture do not require separate accelerated ageing testing. Instead, they only need to meet the post-ageing tensile requirements directly, since natural ageing has already occurred. The 6-month period starts from the first day of the month after manufacture.
Gloves tested more than 6 months after manufacture do not require separate accelerated ageing testing. Instead, they only need to meet the post-ageing tensile requirements directly, since natural ageing has already occurred. The 6-month period starts from the first day of the month after manufacture.
Q4: Can synthetic rubber gloves meet the same requirements as natural rubber latex gloves?
Yes, the standard applies equally to natural rubber latex, synthetic rubber latex, and rubber solution gloves. However, synthetic materials may have different tensile characteristics, and manufacturers must ensure their specific formulation meets all requirements including ageing performance.
Yes, the standard applies equally to natural rubber latex, synthetic rubber latex, and rubber solution gloves. However, synthetic materials may have different tensile characteristics, and manufacturers must ensure their specific formulation meets all requirements including ageing performance.
