Thursday, December 23, 2010
Friday, December 3, 2010
How to Become Exam Grade
In the last blog, we mentioned that special testing is required in order for a glove to be used in any type of medical application. So, what are these tests? Well, before we explain the tests, here are some terms you need to know:
Acceptable Quality Level (AQL) is the minimum manufacturing requirement needed for a glove to pass for exam grade. In the United States the AQL must be 2.5 or less.
Tensile Strength is the maximum stress that a material can withstand while being stretched or pulled before becoming deformed.
Megapascal (MPa) is the unit of measurement used in the tensile strength test. 1 Mpa is equal to approximately 145 pounds per square inch.
Now that you understand the terms, here are the three main tests used in order for a glove to be labeled (or classified) as exam grade:
Water Test
This test is used to determine the AQL of the glove. The test detects holes that allow water leakage in the glove. Each glove is filled with water to determine if any pinholes exist. Any holes in the glove count as a defect. The AQL score is then calculated by the number of defective gloves for every 100 that were tested. For example, if out of 500 gloves only 6 had any defects, the AQL for that batch would be 1.2.
All of our gloves have an AQL – industrial or exam grade. This can be confusing because sometimes people think that if there is an AQL, then it must be exam grade. This is absolutely not the case. As I said before, the FDA requires the AQL for exam grade to be 2.5 or lower. So when you see an AQL above that, know that it is an industrial grade glove.
Blood-Borne Pathogen Test
This test method is used to measure the resistance of penetration by blood-borne pathogens. Phi-X174, one of the smallest measurable viruses in the world, is used to test the glove’s ability to act as a barrier. If the glove acts as a good barrier to the Phi-X174 virus, it is considered a good barrier against larger viruses such as Hepatitis B, C and HIV.
Tensile Strength Test
There are two parts to this test. First, there is the test to get the tensile strength, which is determined by how much stress the glove can take before becoming deformed or breaking. Using a universal testing machine, the glove is tested and measured by MPa until the breaking point.
The second part of the test is measuring the elongation percentage. The glove is stretched until it breaks, then measured to see how much longer the glove is versus before it was stretched.
For example: The glove starts out at 9 inches long. After stretching and breaking it, the two remaining pieces are 54 inches long. The elongation percentage would be 500%. Here is how it is calculated:
There are other tests such as determining how much latex protein is in a latex glove and how much powder is still on a powder free glove, but these three are the main tests. According to the American Society for Testing and Materials (ASTM), the following are the minimum requirements from these three tests for Latex, Vinyl and Nitrile gloves:
Even though there are only three main tests, the results are what make the difference in what grade the gloves fall into. Remember that you should use exam grade gloves in any type of application where you could come in contact with blood or bodily fluids. And although having AQL numbers on industrial grade gloves can be confusing, remember that unless it says “Exam” it isn’t.
Acceptable Quality Level (AQL) is the minimum manufacturing requirement needed for a glove to pass for exam grade. In the United States the AQL must be 2.5 or less.
Tensile Strength is the maximum stress that a material can withstand while being stretched or pulled before becoming deformed.
Megapascal (MPa) is the unit of measurement used in the tensile strength test. 1 Mpa is equal to approximately 145 pounds per square inch.
Now that you understand the terms, here are the three main tests used in order for a glove to be labeled (or classified) as exam grade:
Water Test
This test is used to determine the AQL of the glove. The test detects holes that allow water leakage in the glove. Each glove is filled with water to determine if any pinholes exist. Any holes in the glove count as a defect. The AQL score is then calculated by the number of defective gloves for every 100 that were tested. For example, if out of 500 gloves only 6 had any defects, the AQL for that batch would be 1.2.All of our gloves have an AQL – industrial or exam grade. This can be confusing because sometimes people think that if there is an AQL, then it must be exam grade. This is absolutely not the case. As I said before, the FDA requires the AQL for exam grade to be 2.5 or lower. So when you see an AQL above that, know that it is an industrial grade glove.
Blood-Borne Pathogen Test
This test method is used to measure the resistance of penetration by blood-borne pathogens. Phi-X174, one of the smallest measurable viruses in the world, is used to test the glove’s ability to act as a barrier. If the glove acts as a good barrier to the Phi-X174 virus, it is considered a good barrier against larger viruses such as Hepatitis B, C and HIV.
Tensile Strength Test
There are two parts to this test. First, there is the test to get the tensile strength, which is determined by how much stress the glove can take before becoming deformed or breaking. Using a universal testing machine, the glove is tested and measured by MPa until the breaking point.
The second part of the test is measuring the elongation percentage. The glove is stretched until it breaks, then measured to see how much longer the glove is versus before it was stretched.
For example: The glove starts out at 9 inches long. After stretching and breaking it, the two remaining pieces are 54 inches long. The elongation percentage would be 500%. Here is how it is calculated:
There are other tests such as determining how much latex protein is in a latex glove and how much powder is still on a powder free glove, but these three are the main tests. According to the American Society for Testing and Materials (ASTM), the following are the minimum requirements from these three tests for Latex, Vinyl and Nitrile gloves:
Even though there are only three main tests, the results are what make the difference in what grade the gloves fall into. Remember that you should use exam grade gloves in any type of application where you could come in contact with blood or bodily fluids. And although having AQL numbers on industrial grade gloves can be confusing, remember that unless it says “Exam” it isn’t.
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