I have had these symptoms described in short lifetime UV protective spectacles,
which in most cases have come down to the cleaning solutions used. Polycarbonate
is usually very resistant to cleaning with alcohol, for example, and most
acrylics seem to survive alcohol cleaning solutions and sprays, but our phototherapy
team have managed to destroy, even melt, visors and spectacles by cleaning
with certain hospital-intended green cleaning solutions, whose contents we
can only guess at. Crazing, cracking and softening of the materials in the
eyewear seem to be associated with what you splash on to clean them.
Have you been able to verify exactly what has been used every time the eyewear
needed cleaning, or do you just get an answer that reflects the most common
cleaning method? It doesn't take more than one or two exposures to the wrong
stuff to start the destructive processes going (I am still trying to establish
my boundaries to ethanol exposure, and haven't found them yet).
>-- Original Message --
>Date: Tue, 11 Apr 2006 17:16:42 +0100
>Reply-To: British Medical Laser Association <[log in to unmask]>
>From: Harry Moseley <[log in to unmask]>
>Subject: Re: life expectancy of laser safety eye wear
>To: [log in to unmask]
>
>
>Matt
>
>This is an interesting and practical issue. We recently returned
>eyewear (2 pairs both with plastic lenses) that had developed numerous
>cracks within 18 months or so. At no time were they dropped or
>mis-handled and they were cleaned in accordance with the manufacturer's
>instructions. I now see that our new eyewear is developing small cracks
>after only a few months. I am wondering if the material is stressed
>during the manufacturing process. Perhaps there is someone out there who
>can enlighten us about the manufacturing of eyewear?
>
>Re-certification would not be worthwhile as it is very expensive.
>
>Regards
>Harry
>
>
>Harry Moseley
>
>Hon. Reader
>Consultant Medical Physicist
>The Photobiology Unit
>University of Dundee
>Ninewells Hospital & Medical School
>Dundee
>DD1 9SY
>United Kingdom
>
>Tel: (0)1382 633894
>Fax: (0)1382 646047
>
>
>>>> [log in to unmask] 4/11/2006 4:51:27 PM >>>
>during an HSE inpsection today
>one (of the few) question was raised about renewal intervals for Laser
>safety eye-wear.
>
>Obvious damage etc renders end of life.
>
>Any members/ manufacturers/ suppliers experience of replacement
>interval
>
>is each manufacturer different,
>Do some products last better than others, eg stability of filter
>system, glass vs plastic etc
>
>Or would it be prudent to have eye wear re-certificated at intervals
>
>Matt
>
>Matt Williamson
>Laser Protection Advisor
>Medical Physics
>Leeds General Infirmary
>tel 01924 212900
>mobile 07768 987956
>[log in to unmask]
>
>
>
>Matt Williamson
>Consultant Clinical Scientist
>Head of Clinical Physics
>Pinderfields General Hospital
>Wakefield
>tel 01924 212900
>pager 07699 648631
>mobile 07768 987956
>[log in to unmask]
>
>
>
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