Instron's Guide to PPE Testing
Materials Testing Guidance for Personal Protective Equipment
The global demand for medical equipment has skyrocketed in response to the COVID-19 pandemic, with many companies refocusing their efforts to produce personal protective equipment (PPE). With this vast uptick in demand, medical device manufacturers have scrambled to increase their production capacities while non-medical manufacturing companies have transitioned their own production facilities to create items such as masks, gloves, and nasal swabs. With increased manufacturing comes increased quality control testing, and Instron has received numerous inquiries from companies seeking to expand their testing capacity or reconfigure their existing equipment to test PPE. This guide was created to help familiarize manufacturers with key testing requirements and provide an overview of current FDA regulations. We hope that it will be a useful resource for anyone seeking to aid the fight against COVID-19.
ASTM classifies medical gloves according to their material (latex, nitrile, natural rubber, PVC, or polychloroprene), while ISO classifies them based on their application (patient examination or surgical). Regardless of the testing standard, material, or clinical application, the equipment and general procedure for testing is consistent across all medical glove types. ASTM D6319, ISO 11193, and EN 455-2 are standards used by the biomedical industry to regulate the tensile properties of medical gloves. The key results for all glove testing standards are the tensile strength and ultimate elongation of the material. Rather than testing the entire glove, a dogbone specimen is cut from the finished glove and testing in accordance to the relevant elastomeric standard (ASTM D412 or ISO 37).
|Glove Test Setup|
A 500N load cell is an appropriate capacity for all glove materials.
Air pressurized grips ensure consistent clamping forces Jaw faces are easily interchangeable to ensure the correct surface texture is used for the material. Elastomeric materials like rubber gloves typically require rubber coated faces due to how thin the specimen is. The rubber coating is able to prevent slippage of the material without damaging the specimen.
The biomedical method suite includes preconfigured methods for EN455-2
|4)||Elastomeric Roller Grips
Roller grips provide a cost effective gripping solution for thin elastomers The roller grip utilizes a proportional clamping pressure which increases as more force is applied to the specimen
An optical non-contacting strain device can be used to ensure more accurate strain measurement
All the major ASTM/ISO/EN standards require a dumbbell shaped specimen to be stamped from the palm of the glove EN 455-2 takes into consideration the potential discrepancies in thickness between the palm and the fingertips. The standard compares their thickness and uses a correction factor for the tensile strength of the speicmen.
The Food and Drug Administration is the main regulatory body overseeing the production and distribution of PPE in the United States. The level of FDA involvement depends on the class of the device, which can range from class 1 to class 3 based on the device’s potential risk of nonconformance. Most types of PPE are labeled as class 1 devices, which have the fewest barriers to approval.
Because it can take months or even years to gain FDA approval, in times of health crisis the FDA issues something called an Emergency Use Authorization (EUA). An EUA essentially loosens the requirements for production and distribution of certain medical products to allow production to ramp up quickly. EUAs are currently being granted to manufacturers of COVID test kits, virus therapies, ventilators, respirators, and PPE. These emergency authorizations are generally granted to specific companies who apply to expedite the approval process, but they are also being released as blanket statements covering certain types of PPE so that smaller companies can also participate with minimal red tape. The EUAs include additional documentation that outline the enforcement policy for PPE manufacturing during the current public health emergency and provides criteria for quality control standards as well as the required labeling of products released under the authorization.