EN455-4:2009 image of doctor with green gloves

EN455-4:2009 is the European Standard that outlines the requirements and testing methods for determining the shelf life of single-use medical gloves. This includes surgical and examination gloves made from materials such as latex, nitrile, and polyisoprene. 

The standard emphasizes the importance of collecting aging data within a reasonable period for designs lacking such information, and it provides comprehensive guidelines for existing, new, and significantly modified glove designs. 

Compliance with EN455-4:2009 is essential for ensuring that gloves retain their quality and effectiveness over time, and the standard specifies stringent requirements for labeling, sterile barrier integrity, and storage conditions to maximize shelf life. The standard applies to a wide range of gloves and implements accelerated aging test methods and real-time stability testing to safeguard healthcare professionals and patients against the risk of cross-contamination. 

This introduction aims to provide a grounded understanding of the standard’s stipulations and the importance of adhering to it to ensure medical gloves’ durability and safety.

Introduction to EN455-4:2009

EN455-4:2009, as an essential component of the EN455 standard, and is dedicated to the shelf life determination of single-use medical gloves. 

The key aspects of EN455-4:2009 include:

  • Scope and Application:
    • The standard applies to existing, new, and significantly changed designs of medical gloves.
    • It mandates the generation of aging data for existing designs lacking such information.
    • It covers a wide array of glove materials such as latex, nitrile, and polyisoprene, addressing their natural aging properties.
  • Testing and Requirements:
    • It incorporates accelerated ageing test methods and real-time stability testing to determine shelf life.
    • Specifies force-at-break requirements for examination and surgical gloves made from different materials, ensuring their durability and reliability over time.
  • Regulatory and Technical Committee Involvement:
    • EN455-4 is drafted under the guidance of CEN/TC 205/WG 3 – Medical gloves, reflecting the collaborative efforts of experts in the field.
    • Aligns with the Directive 93/42/EEC concerning medical devices, emphasizing its critical role in maintaining high standards for medical gloves.

EN455-4:2009 not only sets the maximum shelf life claim at five years from the date of manufacture but also underlines the importance of rigorous testing to uphold the protective capabilities of medical gloves against cross-contamination risks.

Key Requirements for Shelf Life Determination

As mentioned the EN455-4:2009 standard specifies key requirements for shelf life determination, incorporating both accelerated and real-time testing methodologies. These requirements are essential in maintaining glove quality and preventing health risks associated with expired or improperly stored gloves.

  • Testing Requirements and Procedures:
    1. Force at Break: After both accelerated and realtime aging, a test for force at break must be carried out according to the specifications in EN455-2:2015
    2. Freedom from Holes: After both accelerated and realtime aging, a test for freedom of holes must be carried out according to the specifications in EN455-1:2020
    3. Pack Integrity (Sterile Gloves Only): After both accelerated and realtime aging, a test for pack integrity as per EN ISO 11607 is mandatory to ensure sterile barrier integrity.
  • Shelf Life Determination Methods:
    • Real-Time Stability Testing: In the real-time study, the shelf life should be determined based on the specific storage conditions specified by the manufacturer. For example, if the manufacturer states that the product should be stored at 25°C, then the real-time study should be conducted at this temperature. 
    • Accelerated Stability Studies: Based on kinetic principles, this method assigns a provisional shelf life that must be verified by the real-time studies. Claims based on accelerated aging should not exceed three years.
  • Regulatory Compliance:
    • Before market placement, manufacturers must conduct stability tests on new or significantly modified gloves, including real-time stability studies. Any significant product change necessitates re-determination of shelf life. According to EN455-4:2009 the maximum shelf life claim allowed is five (5) years from the date of manufacture.

Accelerated Ageing Test Methods

Accelerated ageing determination serves as a predictive tool for assessing the shelf life of medical gloves. Utilizing the Arrhenius equation, this method estimates the time required for the physical properties of gloves to deteriorate, factoring in the rate constant of a degradation reaction at varying temperatures. This equation is key in accelerated ageing studies, enabling a scientific approach to predict longevity and maintain the integrity of gloves until their use.

Procedure for Accelerated Ageing Studies:

  1. Gloves from the same production lots designated for real-time shelf life determination are selected.
  2. These gloves, whether packaged individually or taken from bulk packages, are subjected to a specific ageing process. They are placed in an oven at a temperature of (70 ± 2) °C for a duration of seven days, as per the guidelines outlined in ISO 188:2007, clause 4.
  3. Post ageing, Force of Break and Freedom of Holes tests are conducted.

This process ensures that the accelerated ageing studies are conducted under standardized conditions, providing reliable data for manufacturers to predict shelf life accurately and ensure the safety and effectiveness of medical gloves.

Real Time Stability Testing

Real-time ageing studies provide a direct assessment of a medical glove’s shelf life under typical storage conditions. This method complements the accelerated ageing studies, offering a more accurate picture of a glove’s deterioration over time.

Procedure for Real-Time Ageing Studies:

  1. Sample Selection: Gloves from the same production lots designated for accelerated aging are chosen.
  2. Storage Conditions: These gloves, whether packaged individually or taken from bulk packages, are stored under controlled conditions as specified in EN 455-4:2009, Annex A (typically room temperature and humidity).
  3. Testing Schedule: Over the designated shelf life period, samples are periodically retrieved from storage and subjected to testing as outlined in the standard. This includes Force of Break, Freedom from Holes, but could also include other relevant tests depending on the glove type.
  4. Data Analysis: The collected data on physical properties over time is analyzed to determine the point at which the gloves degrade beyond acceptable performance levels.
    • This approach allows manufacturers to establish a realistic shelf life for their products, ensuring optimal performance and user safety throughout the gloves’ intended use period.

Conclusion

Through the comprehensive exploration of EN455-4:2009, it becomes evident that the standard plays a crucial role in ensuring the safety, durability, and effectiveness of medical gloves over time. By establishing rigorous requirements for shelf life determination, including accelerated ageing test methods and real-time stability testing, EN455-4:2009 serves as a foundational guideline that helps mitigate the risk of cross-contamination in medical settings. The emphasis on detailed testing processes, regulatory compliance, and strict labeling requirements underscores the standard’s commitment to upholding high-quality manufacturing practices within the medical glove industry.

As we reflect on the significance of EN455-4:2009 for both manufacturers and end-users, the broader implications of adhering to such standards become apparent. Ensuring glove integrity not only protects healthcare professionals and patients but also reinforces trust in medical products. By following these guidelines, manufacturers are also prompted to engage in ongoing research and development to further enhance glove safety and performance. Ultimately, the rigorous application of EN455-4:2009 standards exemplifies a steadfast dedication to improving healthcare safety standards, prompting continued advancement in medical glove production and usage.

FAQs

What is the defined shelf life according to EN455 standards?

The EN455 standard, particularly EN455-4, specifies that medical gloves should have a shelf life of at least three years and up to five years. It is only allowed to dertermine the shelf life on accelerated aging for three years. If the manufacturer wants to write a shelf life exceeding three years, they need to base it on real time testing.  

How long can you expect medical gloves to last before they expire?

Latex gloves are generally expected to last for up to three years, while nitrile gloves can have a shelf life of up to five years if stored under optimal conditions, which include proper temperature and lighting.

Can you explain what EN455-4 encompasses?

EN455-4 is a part of the EN 455 standards that outlines the requirements for evaluating the biological safety of medical gloves intended for single use. It includes provisions for labeling and information disclosure regarding the test methods employed in the evaluation process.

Is there an expiration date on medical gloves?

Yes, medical gloves do have an expiration date. Latex gloves typically have a shelf life of three years, whereas synthetic gloves such as nitrile, neoprene, and vinyl can last up to five years if stored correctly. It is even possible to use the gloves beyond ten years if they have been properly stored and show no signs of damage or deterioration.