As reported earlier, here, we reviewed several pairs of Phillips Boroscope filters and checked them against the American National Standards Institute standard for safety eyewear (ANSI Z87).

At the same time, we sent a lens out to be tested for its transmission spectrum.

The testing company is Optical Data Associates, LLC. They are a well-known and respected company that does nothing but spectrophotometric testing for others, including the U.S. Government. You can visit their web site here. The tests were performed by Dr. Michael Jacobson, on a Varian Cary 500E UV-Vis-NIR spectrophotometer.

For us, the results of the test were astonishing, to say the least.

Phillips Safety, on its web site, makes the following statement: "Phillips Boroscopes were designed to meet the need for extra IR and UV radiation protection when working with borosilicate glass."

Note the phrase "designed to meet". To give Phillips Safety the benefit of any doubt, they probably instructed their subcontractor to manufacture a lens that reduces UV and IR for safe use by borosilicate workers.

Later, they write: "Boroscopes should be worn when working on hard glass types where regular didymium or ACE-202 are not adequate due to the fact of insufficient filtration of ultraviolet and infra-red absorbtion." This is very true. Borosilicate workers do need additional filters to reduce the IR levels generated by working borosilicate glass to safe levels.

If you look at the transmission charts prepared by us through the use of data provided by Optical Data Associates here, you will see that there is a major discrepancy between the claims on the Phillips Safety web site (and those of its distributors) and the actual factual data from the spectrophotometric testing. Most disturbing is the fact that the Phillips Boroscopes sample that was tested was found to actually transmit better than 50% of IR between approximately 950 nm and 2300 nm, the most hazardous to the eye portion of the IR spectrum. This is disturbing because the user is lead to believe, through the claims made by Phillips Safety, and the seemingly universal belief that a dark lens, especially a dark green lens, is safe to use for borosilicate use.

Additionally, their claims of shade number equivalence to the ANSI welding shade table are, based on the sample tested, absolutely untrue. In order to use shade number equivalency, the filter MUST meet both UV, visible, AND IR transmission thresholds per the table below:

The sample that was tested by Optical Data Associates was called a Shade 3 by Phillips Safety. It certainly meets the standard for Maximum Visible light transmission. It absolutely fails, however, to meet the standard for Maximum IR transmittance, which should be 9.0 %, and is actually about 48% over the range tested (900 to 3000 nm).

We should also note that the sample we sent for testing was 3.6 mm thick. If the product out in the field in actual use is thinner, the transmission will be proportionally higher, by as much as 4-6%.

These test results should be a major concern to borosilicate lampworkers who are using this product with the expectation that they are receiving full protection from IR radiation, as advertised by Phillips Safety. The data shows that the Boroscopes filter is only removing slightly less than half the IR the borosilicate lampworker is being exposed to. Borosilicate lampworkers should be wearing eyewear that transmits no more than 2.5 to 9.0 %, based on the ANSI Z87 welding shade table (above).

Phillips Safety compares its filter to the ACE-202 filter, making the statement as noted above, that the ACE-202 filter is not safe for borosilicate workers, leading the reader to believe that its Boroscope is adequate for borosilicate workers. If you look at the transmission chart for the ACE (which we call AUR-92), you will see that there is actually very little difference in the mid-range IR transmission between the ACE-202 and the Boroscope filter. The ACE-202 transmits between 70 and 80% IR, while the Boroscope transmits between 50 and 60% IR. A 20% reduction in IR is not enough for borosilicate workers, especially those who are working large production pieces. What is occuring is known as the "sunglass effect". With a dark lens, the pupil opens up wide to allow more light to enter the eye. When the lens also transmits high levels of IR energy, more of this energy enters the eye because the pupil is wider open than normal. So, potentially, the 20% reduction in IR is offset by the wider opening of the pupil of the eye.

Several distributors have taken the Phillips Safety statements a step further: "These glasses are very suitable for working borosilicate glass and soft glass." In light of the above information, we hope that these distributors will re-examine the information they are presenting to their customers.We do not fault the distributors of this product, as they are only reprinting the materials supplied by the company providing the product to them. If you have concerns about the safety of the product, please contact Phillips Safety.