What Does AQL Mean?
...and How Does it Impact Safety Glove Selection?
Safeguarding the hands of workers is an increasingly technical process given the development and inclusion of advanced fibres and materials engineered into safety gloves today.
For safety managers a range of EN standards exist to help them identify and specify the right gloves for workers.
Whilst some of these standards are more commonly understood – including EN374 and EN388 – the EN455-1 AQL certification often goes under the radar with many people not aware of the test or the significance of the results.
So what is an AQL and how does it meet EN455-1?
The Acceptable Quality Level (AQL) is an internationally recognised quality standard designed to assess the statistical quality control of products such as medical protective gloves. In particular measuring for the % likelihood of pinhole defects in a batch of disposable gloves.
How did AQL develop?
The advent of mass production manufacturing following the industrial revolution created challenges when it came to ensuring the consistent quality of products produced on such a large scale.
The challenge was this - how do you ensure that your customers receive the quality of product that they expect without inspecting each and every item manufactured? For quite some time no solution was available and industry continued to manufacture millions of products without any agreed and systematic way of checking their quality.
Eventually, statisticians working for the US Army between the Great War and Second World War devised a series of statistical tests enabling a small proportion of randomly chosen samples from each batch of ammunition to be tested.
From these tests, results from this small proportion were then used to accurately predict the behaviour of all of the untested ammunition. This test method proved so successful in predicting the performance of ammunition that the military started using it to control the testing of their other bulk purchases.
By the 1970’s the UK recognized the effectiveness of this approach, adopted the tables and re-published them as British Standard BS6001. The international community then followed suit, re-publishing them as International Standard ISO 2859.
Today almost every statistically controlled mass production process uses these tables to sample and test its output.
When it comes to measuring the effectiveness of gloves in protecting workers hands against the hazards, ensuring quality and safety is essential.
How are gloves tested to create an AQL score?
A defined number of gloves from a production batch are selected and tested for water-tightness (detection of holes) which is determined by a leak test. In the test, the gloves are filled with 1000ml of water and then observed for a defined time period. The test is considered passed when no water leaks from the glove, proving that it has no holes.
An AQL result of 1.5 accepts the statistical probability that there are less than 1.5% of the products with defects in the batch of gloves. An AQL of 0.65 assumes a more stringent quality acceptance level, allowing the wearer to have a higher degree of personal protection.
How does the AQL apply to gloves and what do I need to look for?
The most important thing to remember when it comes to AQL is that the lower the AQL number rating, the greater the quality of barrier protection the wearer will have.
European Standard EN455 states that medical examination gloves shall have an AQL score of 1.5.
The most common AQL numbers in the UK and Europe are 1.5 and 4.0. However, you can also get 1.0 and 0.65 AQL rated gloves which are often used in some specialist areas such as microbiology labs and surgery.
As an example of this, Globus has worked with global manufacturer SHOWA to launch a new range of premium single use nitrile gloves combining comfort, dexterity and chemical protection.
Silicone-free and powder-free for safer use, the new range of single use nitrile gloves includes accelerator-free, antistatic and hi-viz versions. They also feature AQL ratings ranging from 0.65 to 1.5.
To find out more about AQL and protective gloves, you can contact the Globus team on, +44 (0)161 877 4747 or email firstname.lastname@example.org.Leave a Comment
Thoroughly informative blog.
I have a concern about the adequacy of the standard AQL test. Due to the surface tension of water the standard glove test only identifies holes down to around 20 µm. Bacteria and viruses can penetrate through holes much smaller than this. The condom test will detect holes down to around 1Å (10-10m). Bacteria are significantly larger, i.e about 1µm (10-6m). I once saw a test on single-use vinyl gloves performed in the USA where 500 gloves were tested using the condom test. Over 50% failed this test. I don’t believe this was made public at the time as it was done by the company for a customer.
Given their size, does the standard AQL test provide an adequate test for nanoparticles?