cutting polycarbonate lenses
this is my first post, but I would love to have input on the latest information regarding the health risk of cutting polycarbonate lenses. This question has been generated from the latest findings of polycarbonate in general,causing numerous health risk when used in baby bottles and drinking glasses. I have worked as dispensing optician and done most of the cutting in the finishing lab for an optometrist for the last 20 years.My health has deteriorated to the point where I have had to cut back on my hours and missed lots of work. In any event, I have many of the symptoms associated with the latest findings of polycarbonate,in general. I would think that being exposed to the raw material in the cutting proccess could exacerbate exposure to the toxins. Is there a law concerning exposure within the optical industry? Have the laws been tightened up since new findings are coming out? I would like the latest input in this regard. Thanks in advance for any input you proffessionals can give concerning this topic. Mike
PS: I love this forum
Ventilation is the key....................
Quote:
Originally Posted by
THE MEB
..........................I would love to have input on the latest information regarding the health risk of cutting polycarbonate lenses.
.................................... I have worked as dispensing optician and done most of the cutting in the finishing lab for an optometrist for the last 20 years.My health has deteriorated to the point where I have had to cut back on my hours and missed lots of work. In any event, I have many of the symptoms associated with the latest findings of polycarbonate,in general.
Mike
Mike......... any hot plastic or solvent will emit toxic fumes. The only proper way to work with them and stay healthy is proper ventilation. A ventilation hood directly over the workplace venting the fumes outside, not into a centrally ventilated building endangering others.
http://www.twi.co.uk/j32k/protected/.../faqkg006.html
As you have done optical lab work for 20 years and suffer health effects you must also have a tinting unit under heat all day long, and also without proper ventilation. This is as bad or worse as hot neutralizers emit toxic fumes that have long term health effects on kidneys, liver and brain. So do also some additives in the dyes.
There are also many other chemicals that should be handled under a ventilation hood. Or if you can not start using the tinting systems that does not emit any dangerous fumes.
If you arrange your workplace with good ventilation at the right spots you should be safe. But you should also use water + surfactant based chemicals if possible.
check MSDS.........................
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Originally Posted by
apaul
So any ideas?
Should we be wearing gas masks?
Al
You have the right to request a MSDS (Material safety data sheet) fom your supplier on the cured lens material. Then check the section on toxicity of fumes when overheated or burning.
However if you use a coolant when edging, the problem would simply be an unpleasant smell and not fumes.
Hot plastic materials..................
Quote:
Originally Posted by
apaul
Hope i am not going to ridicule myself but arent smell and fumes the same thing?
Alan
Nothing ridiculous about that. Smells can be or are most of the time harmless if they are emitted from a unheated object, however they can be warning signal.
If you inhale an expensive perfume which consists of a half a drop of concentrate dissolved in ethanol in its normal cold condition you will inhale a non dangerous and minimal amount of the alcohol.
However if you heat the same perfume and start smelling the bottle you will inhale a thousand fold the alcohol which transposed into a gaseous state by heating it up and would be immediately be subject to its toxicity of the chemical.
This same effect you have in your lab with lens dye neutralizer. No problem when smelling it cold but very toxic when hot.
That is why I asked above if you use a dry cutter on your edger or wheel with coolant. The dry cutter would create heat and could release toxic fumes that can develop with plastic materials taht are otherwise safe.
dangers of cutting and grinding
- If you cut or grind you will have dust and vapor. You need proper dust collection and proper ventilation for the vapor. If you smell something, then you surely have vapor.
- The same dust you see on your counter is also collecting in your lungs, which is why wearing a mask is smart. The dust collection in your lungs is cumulative. It does not pass. It takes a number of years to discover the heath threat. Then it is a little late. The learning process is much similar to that which folks learned about with mining coal and asbestos. The optical industry tends to pretend this is not an issue. One day this will be just as big an issue as in those other industries. This will hit the guys without proper dust collection and ventilation where is should, in the wallet. Because you do not see or feel it quickly is a lousy reason to be lazy and cheap.
Regarding smells of high index...
Pulled this past post of mine that new optiboarders may find interesting-
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Join Date: Dec 2004
Location: Where Fezz used to be...
Posts: 474
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Memorandum from Seiko 6/2/1997 RE: New SLU Resin Odor
Took a CE class a few years back and asked the instructor about the odor of the very high index lenses and if it was toxic. Her reply was "that's the smell of money". So I again asked if it was toxic and she said only in extremely high concentrations that no lab environment could produce which made me curious as to how high extremely high was.
Found a lab who faxed me the following Seiko Memorandum addressed to Distribution.
"AS you may have had inquires from your customers regarding the odor of our new.......
In reviewing the Material Safety Data Sheet (MSDA), hydrogen sulfide is the only classified chemical class with an established threshhold limit value (TLV). This occupational exposure limit is set by the American Conference of Governmental Industrial Hygenists. The actual TVL at time weighted average (TWA) is 10 parts per million (PPM) or 14mg/m[to the (3rd?)]. This TWA translates to a safe concentration level for a normal 8 hour workday and a 40 hour work week, to which nearly all workers are constantly and repeatedly exposed without any adverse health effect.
Seiko states that when our lenses are processed under the worst conditions (dry edger with no ventilation or air circulation), that only extremely small amounts of hydrogen sulfide are released. The actual measured results at 5-10 cm around the edging point are 0.01 PPM or less. This is to say the exposure is 1,000 times less than the TLV-TWA. Therefore, it would be safe to say that if a person in a three foot cubic room was to edge 100 lenses at the same time and exposed to that atmosphere all day for a 40 hour work week conditions would still be 10 times less than the established TLV amounts."
They proceed to recognize the lenses smell like rotten eggs when edged and suggest to wet edge, ventilate, use deoderizers and "problematic or sensitive employees could be advised to wear dust masks."
There is no mention of how thick the test lenses are.
Fester
P.S. According to "New Scientist" magazine on 7/28/2001 and "Biochemical Pharmacology" Vol. 62, 2001 flatulence (word for the day?) is primarily-- you guessed it(!) hydrogen sulphide :eek:
(Can a chemist among us confirm hydrogen sulfide and sulphide are the same? I'm hoping not!)
Judy- Were you that instructor? The "smell of money" always stuck with me!
MSDS Data Bases...........................
Alexa provides a full page of free data bases you consult for just about any chemical on the market.