CV and formaldehyde fumes

      The wrong respirator can lead to serious health problems. July 22, 2003

Question
How long do CVs take to cease giving off odors? I'm using Duravar with catalyst and now, four days after spraying (spray and cure temps in the mid/low 70's), the room is still filling with offensive fumes a few minutes after the exhaust fan is switched off. How much longer can I expect the strong odors to be present?

What is the wait period before usage? Assuming the general conditions above, what is the ballpark figure for a waiting period before a piece finished with CV is cured enough to be put into daily usage?

Forum Responses
(Finishing Forum)
From contributor D:
I have never heard of it taking that long. Usually after they are skinned, the odor is gone. Could it be possible that not enough catalyst was added to the Duravar? Otherwise you got me.



Or maybe too much catalyst added?


From the original questioner:
I mixed it by the quart and used the courtesy plastic catalyst cup made by MLC. I added 3.2 oz (as close to the line on the measuring cup as I could get... just how precise need one be?) per quart. I would like to get a beaker and graduated cylinder for general shop liquid measurements.

I have a room full of sprayed pieces and together they still fill the room with a heavy odor.



From contributor D:
Usually after four hours or so spray pieces can be handled well enough to install. In a day they should be good to go.


From contributor C:
I have to disagree with the above responses. We used Duravar for about seven years and sprayed over 200 gallons and have had the same experience you describe with a strong odor lasting over a week. Some residual odor is evident for several months, especially if sprayed in drawers, behind doors, etc. It's the nature of the product. We have since moved on to Van Technologies waterbornes. The only recommendation I can make is leave the booth fan on or place the finished items in front of a fan until ready to ship.


Welcome to CV. The PTSA reaction in CV lasts a long time. This is why the Europeans use 2k urethanes more than CV. That odor you smell is formaldehyde gassing off from the reaction taking place as it cures. Some products are worse than others. I would, if possible, set the products outside in the shade and let them gas.

Bob Niemeyer, forum technical advisor



From contributor D:
Contributor C, that is good to know. My only experience with CV was SW CV that a previous employer used and in that case, I never noticed the odors like described above. But it was a large building and that may explain it.

As far as Van Technologies goes, I use them too and feel they are an excellent company.



From the original questioner:
Thanks for the insights. Bob, what health hazards are associated with breathing in all these fumes? My shop space is small, so I don't have additional storage facilities to place the work in as it continues to cure - I'm in the same atmosphere as it. Am I poisoning myself? I have noticed a mildly irritated respiratory track and attendant phlegm.

This is my first time spraying the CV. I'll have to evaluate the pros and cons. I spoke with an ML Campbell tech before buying and they mentioned extremely low levels of formaldehyde... but I'm now thinking about how many manufacturers misled customers (or just plain misinformed customers who didn't do their homework) with hazardous coating products.



When they talk about low formaldehyde formulations, I want to laugh. The formulas do have a very small amount in them. It is a required part of the reactive resin and is put in by the resin manufacturer.

But during the curing of the coating itself after you have added the PTSA, it gasses off many times the levels they report. I have been seeing the "E-1" standard floating around for a long time and I feel it is just a marketing tool.

As for your health, I had the same reactions you currently have and about the best thing you can do is just keep the air moving and exchanging. A cheap box fan will do wonders to blow the fumes out of the shop as the finished product cures.

Don't get me wrong - CV and all other coatings emit stuff that is no good for us and we have to deal with it. Even waterbased products have toxic products. I look at it this way - CV=formaldehyde fumes for days and low levels for weeks. And 2k urethanes have all the reactive isocyanates gone as soon as they are dry to the touch, with most going up the spray booth stack.

Bob Niemeyer, forum technical advisor



From the original questioner:
Well, it certainly was an eye opener. During mixing and spraying I had worn my half face respirator that seemed to do the job - good fit, no fumes getting through, etc. I'm wondering, though, if the post-spraying cure period isn't as heavily toxic, or more so, than the actual spraying.

After spraying, I had my exhaust fan running nearly non-stop pulling fumes out the shop, but the finished pieces were in close proximity to me while they were curing and happily off-gassing to their hearts delight. I even wore my respirator a great deal of my time in the shop post spraying (and I'm there about 14 hours daily). When I had the respirator off and walked near the units, the reek was evident.

1.5/2 days after spraying my lungs felt like I had just smoked three packs of cigarettes in succession. Upper respiratory tract congested, tight, breathing feeling labored, some coughing, all that. Much luggie hocking. Nose blowing. Day two I vacated the shop in late afternoon to get away and was feeling mildly feverish, like I had the flu (which in all honesty, I might have had by coincidence... who knows?). Night of day two I noticed small specks of pinkish-red in my phlegm.

Day three (today) the shop odors have dropped down several notches, but if I draw up close to the works and breath I am repulsed, gah! I have avoided the shop today except for a couple hours.

Is this perhaps some sort of toxicity poisoning? Does anyone know what the medical toxicity effects are of CVs when inhaled (especially during curing)?

Serious stuff. I'm going to reconsider my continued usage and/or plan to spray so I can vacate the shop for 2-4 days post spraying.



You may or may not have had a reaction. I would see your doctor just to confirm and talk with him about you concerns.

I would get a weird low grade fever when working in a confined area shooting CV (i.e. a kitchen or a high-end home office with lots of woodwork). I would vent very well but the body can only handle so much. The low grade fever would only last about a day. Everyone's different - listen to your body!

Bob Niemeyer, forum technical advisor



From the original questioner:
For those interested, here's an update.

My cough is still with me two weeks after last spraying the CV. It's a forceful, sharp, shallow cough. No phlegm is coming up, but the cough persists.

I discovered an abysmal error on my part. I had looked over the 3M info for my half-face respirator canisters, and I had thought I was good to go for the formaldehyde. However, during cough week I had another look, and called a local supplier. He said the canisters were *not* filtering the formaldehyde and it was passing right through and into my lungs. Gah! We're talking about 3 gallons of CV, with marginal at best spraybooth/ventilation and post-spraying crosslinking fumes. Yummy.

Well, this is after the fact, but I ordered a new half face respirator as I just now found out 3M is rearranging its product line and has discontinued my model and will no longer support it for canisters. I got a North half-face with organic/formaldehyde canisters. I also got a supplied fresh air respirator with an electric pump and respirator hood for future use of whatever nasty crap I'm shooting.

Went to hospital emergency room but they didn't help much. They said if I was unconscious then I would have done damage and would need help. I'll need to visit a doc with respiratory experience to get the gruesome details. From the few science types I've discussed formaldehyde with, apparently it 'fixes' tissue and cells.

Be safe - double check your gear, and replace those beat-out canisters.



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