We aren't yet committed to switching to post-cat polyurethane but it has several advantages over conversion varnish that we like (low/no odor to the client, exceptional durability, very elegant look/feel).

My main concern is safety and health. Obviously we provide our spray team with vapor masks and optional disposable plastic suits, and the whole spray booth area has plenty of fresh air flow.

I'm aware of the offgassing of isocyanates with post cat Poly. I'm aware that a lot of companies require their employees to wear the disposable suits, and we want to stay as safety minded as possible here.
However, our climate is also much hotter than it is cold. We're deep southeast, and coastal, so it's hot and humid MOST months of the year.

I want to be realistic. If I switch over to a finish that requires wearing a tyvek/plastic suit just to spray it and stay healthy, there's a pretty strong chance I'm going to have a hard time finding anyone willing to deal with that.

So here's my question for you guys that spray post-cat poly for cabinetry and similar high production--- what is your manufacturer saying you need to do for safety? What have you found your finish team prefers doing? What are you offering as "optional" equipment, and what are you requiring they use?

Hello ! With all those equipaments you already have there will be no problem for your workers. If you read all the MSDS you will find out that Pre-Cat or CV are also dangerous, in my opinion using masks and cabin is ok.
The PU system is the best to apply in your city, humidity is good for them. And you will use less material and get better results. Make a 3 month trial , take notes, and you will check by yourself. Have a nice day!

I am not sure what you mean by "cabin", can you clarify what you are calling a "cabin"?

I do appreciate your advice though, very helpful.

If I was working in your spray booth 8 to 10 hours a day, I would require an air supplied full hood in the booth. Too many finishers don't think they will be the ones for organ damage from chemical exposure, until they are diagnosed with it in their late 50s. Too late then!

I agree with the supplied air hood which I find way more comfortable than a half face mask.Especially in hot weather having cool air flowing over your face.
isocyanates have no smell so it’s hard to tell if a regular mask’s filters are good

Mat, 2k urethanes that use isocyanates as a hardener do not "off gas" as you state.
The isocyanate binds with the resin, it does not "off gas".
The finishers are only exposed to free isocyanates in the wet film or wet overspray.
I have been using it for over 30 years and when I spray I wear a mask. Yes you can not smell iso's, but when you start to smell the coating in your mask it is time to change cartridges. I just wear a long sleeve T-shirt and gloves. No need for Tyvek, complete over kill, car painters wear them as they are spraying colors and don't want to ruin clothes.
I vary rarely spray CV or precat, Can't stand the smell in the shop from all the off gassing.
Spraying PU's you will not have that weeks of off gassing either on cabinet insides that customers complain about.

Hi Mat ! I am sorry about my poor english. I wanted to say Spray Booth.
I would like to say that nowadays PU chemistry is more safety than in the past. A long time ago one could have a lot of free isocianate in the hardener, because of poor chemical reaction inside the reactor. But today so many reaction problems was solved, and there is almost zero of this free isocianate. This is the chemical which cause a lot of desease on the guys. If I were you, I would ask for your supplier samples of self sealer PU/Acrylic water based 2K. This is the future for us. Good Luck !!

bob I know you are a ICA guy which product do you use for kitchens and baths thanks

bob,

i, too, spray mostly 2k. i was told the iso's are most harmful in aerosol form, but these can be absorbed by humidity in the air (so maybe not that big of a deal). i wasn't under the impression they were any more harmful in the can or dried finish on the ground. is this not your understanding?

i have a fresh air mask and wear a spray suit. hot and more problematic to get around the booth, but very nice protection against harmful chemicals.

This has been very helpful! Thank you all for contributing.

I had been told before (and, I had forgotten) that the isocyanates weren't offgassed but rather present in the fluid and overspray. Thank you gents for clarifying that.

For Kitchens I like Acrylic Urethane finish systems. The trend is a nice open pore right now and Acrylics provide very good distension, a non yellowing film and long pot life. I use the ICA OAC363 topcoats and FAC241 Sealer most often.
The isocyanates are only a big deal when they are still wet. Dry film is not a problem. Wet overspray in the air is an issue, but with a good spray booth and spraying in the same direction of your air flow will help minimize exposure.
We need to remember that the isocyanate levels in our 2k urethanes made today have very low levels of actual isocyanate compared to the products of 20 years ago.
I will take a few parts per million of Iso rather than p-Toluenesulfonic acid used in CV or a Polyfunctional Aziridine Crosslinker used in many waterbased coatings.
Everything has it's dangers, we as finishers just need to be smart and protect ourselves as needed.

Isocyanate is *only* harmful in two situations:
1. In the air, and only in fast moving overspray that has a chance to be inhaled before reacting

2. Contact exposure.

Isocyanates react *very* quickly with moisture in the air. They are also heavier than air.

When i say "reacts fast", that means that studies done by the various health orgs find that brushing/rolling 2k urethanes generates no detectable amount of isocyanate in breathing air[1], even in spaces with *no ventilation*[2].

That is, whatever amount is so small we don't have anything that can even measure it.

So it's basically "whatever gets on your skin/in your lungs before it can react with the air".

See:

http://www.hse.gov.uk/research/hsl_pdf/2005/hsl0560.pdf

h
ttps://www.ncbi.nlm.nih.gov/pubmed/26833099

You should use supplied air, and be very careful, but as the last post said, it's actually probably a lot better for you than spraying CV (in part because people take much better precautions).

thanks bob , have used those products before, I should have ask about pigmented finishes because thats all I seem to do lately do them come in mixable bases?

Take a look at Alcea Coatings. They have an iso free catalyst. We switched to it about 6 months ago from CV and are very happy.

The iso free catalyst is part number 9981/A699

https://www.alcea.com/en/