In industries where contamination control is paramount, particularly in pharmaceuticals, biotechnology, and cleanroom environments, personal protective equipment (PPE) plays a vital role in ensuring both worker safety and product integrity. Among the essential safety measures, double donning has become a critical practice in maintaining contamination control.

This dual-glove technique is a cornerstone of aseptic procedures, reinforcing the need for sterility and ensuring compliance with EU GMP Annex 1.

Why Cleanroom Operators Need to Double Glove?

Single gloving involves wearing just one pair of gloves, providing a basic barrier of protection between the skin and the environment. While it is suitable for general tasks, single gloving may not provide sufficient protection in environments where contamination control is critical. In these cases, single gloves can be prone to punctures, tears, or degradation, which may expose both the operator and the cleanroom environment to contamination.

On the other hand, double gloving involves wearing two pairs of gloves, one over the other, to enhance protection in environments that require strict contamination control and personal protection. The inner glove provides a base layer of protection, while the outer glove acts as a barrier against potential breaches, such as punctures or tears.

Double Gloving and Compliance in ISO Class Cleanrooms

Double gloving is a critical requirement in ISO Class 5 and 4 cleanrooms due to the heightened risk of contamination. These cleanrooms are subject to the strictest cleanliness standards, with even the smallest particles posing a significant risk to both the environment and product integrity. Double gloving provides an essential barrier, and the dual layer of protection not only safeguards workers but also helps maintain compliance.

In ISO Class 6-8 cleanrooms, while double gloving may still be employed, it is less critical than in ISO Class 5 & 4 environments. These classifications permit higher particle counts, so the contamination risk is somewhat lower. As a result, single gloving is generally sufficient for routine tasks. However, double gloving remains recommended, particularly when handling hazardous or sterile materials, as an added precaution against contamination.

Single vs. Double Gloving: Which Offers Better Protection in Cleanrooms?

Chemical Protection:

Exposure to chemicals in cleanroom settings varies based on industry requirements, from handling Active Pharmaceutical Ingredients (API) in pharmaceutical production to working with acids in semiconductor fabrication cleaning.

Single Gloving: Provides basic chemical resistance depending on glove material. However, if a chemical permeates the glove, exposure is immediate.

Double Gloving: The additional glove layer provides extra time before a chemical reaches the skin, enhancing protection. If the outer glove gets compromised, the inner glove can still provide a barrier, reducing the risk of direct exposure. However, this setup may slightly reduce tactile sensitivity. If chemical exposure occurs, both glove layers should be removed immediately.

Puncture Resistance:

Gloves can be punctured by sharp tools, rough surfaces, or accidental contact with contaminants, compromising their protective function.

Single Gloving: If a single glove is punctured, there is no backup barrier, putting the worker at immediate risk. Some gloves are thicker for durability, but this may reduce dexterity.

Double Gloving: Provides a fail-safe mechanism—if the outer glove is punctured, the inner glove remains intact, preventing direct exposure. However, wearing two gloves can slightly reduce tactile sensitivity, making precision tasks more challenging.

Both single and double gloving serve specific purposes in cleanroom environments. Single gloving is sufficient for lower-risk tasks, providing greater dexterity and ease of use. Double gloving, on the other hand, enhances protection against contamination, chemical exposure, and punctures. The choice depends on the level of risk, industry standards, and the application being carried out. Cleanroom professionals should assess these factors to determine the most effective glove strategy for their work.

Double Gloving and Cuff Length in ISO-Class Cleanrooms

Double gloving is expected in ISO Class 5 and 4 aseptic cleanrooms because even minor breaches can jeopardize product and environmental control. In these zones, a second glove layer creates redundancy, while a longer outer cuff, typically 400 mm, helps maintain sleeve–glove overlap during reach and rotation and adds useful splash coverage during routine wipe-downs and transfers. Annex 1 does not prescribe glove length; cuff selection should be justified in the site’s contamination control strategy using observations, task mapping and deviation history.

In ISO Class 6–8 areas, where particle limits are higher and tasks are often lower risk, single gloving can be sufficient for routine work. That said, double gloving remains advisable when handling hazardous chemicals or sterile materials, or wherever your CCS indicates reach, splash, or frequent outer-glove sanitizing that increases wear and the chance of exposure.

Product Integrity: Why Double Donning Matters

In the life sciences industries, maintaining strict contamination control is essential to ensure product integrity and patient safety. A practical example highlighting the effectiveness of double donning comes from a leading pharmaceutical manufacturer. In a study conducted there, the results revealed puncture rates of 8.5% for outer gloves and 6% for inner gloves. Notably, there was only one instance where both glove layers were punctured, and these did not coincide at the same location. This finding underscores that double gloving significantly reduces the risk of contamination, as the inner glove maintains its integrity even when the outer glove is compromised ¹.