So there have been a bunch of threads on lab ventilation recently and the general consensus is good ventilation is necessary.
Does anyone have any suggestions on how to fit a lab with a good system? Is there a company that is recommended or should I contact a local lab supply company to get a vent hood? Is there an optical-specific setup?
I believe PSI has some decent and cost effective ventilation options.
Ventilation in optical lab....................
Venting to the outside is a job you air conditioning company can do easily.Originally Posted by Ory
They are in the business to install ducts and ventilators to push air. All that is special, is that they have to make a hood or 2 with a backdraft flap. This will be your most economical and professional way of doing it.
Before you just spend money, you need to determine how much air you need to move. That is an engineering question and an industrial hygiene question. Speak to a proper professional first. The phone book under restaurant equipment is filled with names of vendors of ventilation hood systems. Additionally, in some markets you may need a building permit and a release from a landlord.
Most importantly it is good business sense to have a safe environment for you, your employees and customers.
Since you are an optometrist, I am assuming that you have a finish lab. Even if you have a full lab, it is almost impossible for anyone to be overexposed to an airborne contaminant in an optical lab environment. This excludes electroplating, or any like products with could have chromic acid. So don't worry, you aren't hurting anyone.
I'm sure the main reason for the question is the smell from high-index lenses, and maybe a tint unit. If this is the case, you will need a couple of things. Foremost you want the keep the lab under negative pressure so the smell doesn't escape to patient areas. Second you want to get the smell out of the lab for employee comfort. You will need a minimum of 2 air-changes per hour of exhaust ventilation to keep the room under enough negative pressure to keep smells inside the lab. For the lab employee comfort, I would suggest about 6 air-changes per hour. Anything over 2 will work, it just takes longer to remove the smell. The more air-changes, the more it costs in heated or air-conditioned air that is being removed from the bldg.
Mechanically, what we are talking about is a small hood and fan vented to the outside, with a backflow flap; just like Chris described. The backflow flap will also keep heated air from escaping when the fan isn't on. Chris is also right, call your heating and air guys.
There was in interesting post on here once where someone removed the light from his Kappa edger and replaced it with tubing connected to an exhaust fan. I thought that was a great solution for the high-index smell and Trivex smoke.
You just got your engineering and industrial hygiene services.
Mark E
BS Mechanical Engineering
MS Environmental Science
Industrial Hygienist for 14 years
Optician for 1 year
Good post Marc..................I just added a little more
Nasal septum lesions and lung function in workers exposed to chromic acid in electroplating factories
The smell form high index lenses could be fumes from the resulting heat from dry cutting the lenses and could be in the the family of acrylic acid fumes, (I stand to be corrected) wich would be "Ethylenecarboxylic acid, Acroleic acid and 2-Propenoic acid. I have found an MSDS on that subject at: http://www.inchem.org/documents/icsc/icsc/eics0688.htmI'm sure the main reason for the question is the smell from high-index lenses, and maybe a tint unit.
In the matter of tinting units the largest danger lies in the use of regular lens dye neutralizer which has been made from glycol ether's of which, when heated produce long term health dangers to liver, kidney and brain. I have made already many post's. Some dyes do also contain toxic additives. So be safe and vent them outside or use products that do not emit fumes and vapours that are dangerous.
Anyone can go to Google, look up “MSDS polycarbonate” and find that poly emits a cocktail of gasses when subjected to heat during curing and friction grinding. Hazardous thermal decomposition products are: carbon dioxide; bisphenal A; phenol; carbonic acid; diphenyl ester; diphenal carbonate; carbon monoxide, hydrocarbons, phenol derivatives, methane.
And don’t forget that the grinding of lenses may place lens dust in the air. Pneumoconiosis, also known as miner's lung, is a lung condition is caused by the inhalation of dust, characterized by formation of nodular fibrotic changes in lungs.
Go ahead; try go get MSDS from lens manufacturers. Some are very cooperative and some are not.
I think you need to do that yourself - Polycarbonate does not emit a cocktail of anything - at least nothing hazardous. Health=0, Flammability=1, Reactivity=0, Special=0
US EPA SARA Hazard Category:
This product has been previewed according to the hazard categories under section 311 and 312 of SARA Title III and is considered not to have met any hazard category.
Yes, processing polycarbonate my release certain fumes (along with any acrylic based plastic), none of which are listed as being hazardous to one's health unless at extremely high doses.
You are absolutely correct; no health hazard from poly when the product is just sitting there. Look farther down on your same MSDS under “Hazardous Decomposition” and take a big whiff. The product decomposes when subjected to heat such as friction grinding and curing.
SARA Title III establishes requirements for governments and industry regarding emergency planning and “Community Right-to-Know” reporting on hazardous and toxic chemicals that are stored in huge volume. Poly does not apply to the definition of hazardous and toxic when applied to public danger.
Then I suggest you wear a respirator when in the lab - or better yet, find a different career path.
While the number of cases of developing miner's lung, silicosis, or any number of dust related diseases in the optical lab is low the possibility is still there.
Ventilation is part of the issue, along with dust in general. I used to work in the lab for 10-12 hours at a go. It was amazing how much dust running an SGX with a vacuum system, the handstones, and 2 professional edgers can make with only 40-60 pair a day. We were wiping off tons of dust from the tables around the handstone, wiping off the machinery, and everything to boot.
Dust does develop and in significant quantities and under the right conditions is can get deposited into the lining of the lungs, making them less elastic, lowering lung volumes and making it harder to breathe.
One doesn't always know if you will be prone to develop a problem till after you discovered you have it.
That is the reason to use ventilation to reduce those chances.
Cassandra
"Some believe in destiny, and some believe in fate. But I believe that happiness is something we create."-Something More by Sugarland
Yes poly will decompose to hazardous materials. By heat decomposition, that refers to burning. Burning any plastic will emit a "cocktail" of hazardous materials. No problem in the lab, though. The most hazardous material you can grind in the lab is glass. It's the only lens material that could cause silicosis, miner's lung, or anything like it.
Fumes............
Any chemicals composition, even when cured, is, when overheated emitting toxic fumes. So why do we have to breathe them into our systems if there are quite easy to do solutions.
However if you have a shop located in an air circulated office building or shopping center, you might encounter some problems by NOT being able to vent to the outside.
Fumes from hot solvents and smoke from plastics can be very toxic, and you are looking at long term damage as you are breathing the stuff a little bit every day.
Last edited by Chris Ryser; 11-02-2006 at 11:51 AM.
Chris is Right. Where does it say that “decomposition” refers to “burning”? The MSDS for water says that it decomposes into hydrogen and oxygen. Water doesn’t burn. It decomposes through evaporation at room temperature. Why can't poly decompose during friction grinding and curing?
Friends, the decomposition materials in the MSDS are published by the manufacturer of the product in accordance with OSHA Hazardous Communications Standard (29 CFR 1910.1200). This leaves me or anybody else with little latitude to interpret.
Concerning the statement that glass is the “the only lens material that could cause silicosis, miner's lung, or anything like it.” Beware of absolute statements from anyone and let this one stand as an example.
Last edited by Reinhardt; 11-02-2006 at 11:42 AM.
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