The rolled water test.
In Europe, about 2.5 million condoms are bought daily. Until recently,
no standard European test for holes existed. Manufacturers and testing
laboratories in different countries used different tests, leading
to questionable safety of condoms being traded across borders. National
testing laboratories from seven European countries, an AIDS charity
and a condom manufacturer decided to see which of five tests is
best. After extensive testing of nearly 200,000 condoms, they found
two accurate and reliable tests which are now included in the European
standard for testing condoms for holes.
Condoms play an important part of modern life. They protect people from sexually transmitted diseases such as AIDS and as a method of birth control, many rely upon them to prevent unwanted pregnancies.
If condoms are to be effective, they must not have holes in them when they come off the production line. Manufacturers and testing laboratories must run routine tests so consumers can safely rely on condoms. Until the mid-1990s, there was not even a European standard for these tests.
Certainly, the tests were being done, but each country could chose a different test as their national standard. This led to much controversy because the results were not necessarily comparable. Possible trade disputes loomed over condom producers. The question was "Which test is the most accurate and reliable?"
First step - draw up a standard
To remove the trade barrier, a European standard was drawn up. It describes two methods for finding holes in condoms. However, no comparative data existed to allow a choice to be made between these two methods. What's more, very little research had been published, in general, on the effectiveness of hole testing methods.
To compare the tests, the European Standardisation Committee proposed that the methods should be tested extensively. National testing laboratories from seven European countries teamed up with an AIDS charity and a condom manufacturer to evaluate the reproducibility, repeatability and reliability of a number of different condom quality test methods.
The first candidate was the rolled water test. Here, a condom is filled with water and rolled on absorbent paper. If the tester finds any wet patches on the paper, the condom is faulty. This test has been used in the UK and in Scandinavia.
Another test, used in France and Germany, is known as the European electric test. This involves filling the condom with a salt solution that can carry an electric current. The tester dips the filled condom into a bath of salt solution and measures the electrical resistance. If the condom has a hole, the resistance is low as the current is not halted by the insulating condom material. A perfect "hole-free" condom, on the other hand, will show a high resistance as the current cannot be carried through the condom.
For completeness, the partners included another three tests in the study. Two of these tests are electrical methods; one was developed in Japan and another in Spain. The final method, the air burst test, blows the condom up like a balloon. Some experts believed that the condom would not inflate and burst if it had any holes.
How did the partners compare the different methods? First of all, the coordinating partner, London International Group (LIG), prepared test samples. They collected three types of condom. "Natural hole" samples, which have failed an on-line quality control test came from LIG's London factory. LIG also "dipped" about 200,000 condoms in their Barcelona plant. These were counted as "good" samples; the normal commercial product, which is not expected to be damaged.
A high power laser cut tiny holes into some of these "good" condoms, to create "artificial hole" samples. Following treatment with spermicidal, silicone or aqueous lubricant, LIG packaged the different samples and sent to them different partners.
Testing the tests
After two pilot studies to iron out all equipment and operator-related problems, the project team began the full study. The consortium pooled their existing testing skills and equipment to compare the different methods. In this work, each laboratory tested the two methods described in the European standard. Three of the laboratories also worked on the other procedures. As the condoms had been specially labelled with a unique six-digit number, the condoms could be tracked without the testers knowing which condoms had holes in them.
During the 30-month project, the partners went through about 180,000 condoms. Much of the project's success lay in applying new statistical techniques to analyse the results. The group made huge advances in the methodology for performing interlaboratory studies on tests which have a positive or negative result, as opposed to those tests which can take a range of values. The project also linked key condom testers for the first time. The coordinator, Dr Nick White of London International Group says: "We have established a friendly network of laboratories."
And the winner is...
The extensive testing and results confirmed that the two test methods in the European standard are in fact the best ones to use. They are the most effective and reliable. The air burst test should not be used alone as a test for holes. It is not a complete and satisfactory substitute. This test, and the Spanish and Japanese tests also produced far too many false positives. Consequently, too many high-quality condoms would be thrown away unnecessarily at the expense of the company and the consumer.
This thorough study of the standard tests gives condom manufacturers and testing laboratories more confidence. They know that the tests actually give reliable results. Likewise, the public can be certain that the condoms they are buying are safe to use. Good health is obviously the first priority but the result also has important economic consequences for the industry with the European market of about 900 million condoms being worth 467 million ECU in 1994.