Hey guys. I have a quick question. I have a bunch of odorless thinners using them for weathering and I was wondering should I be wearing a respirator?
I am not sure what “odorless” in this case means… is it safe to use it this is why it is odorless, or does the vapors toxicity is still there yet you cannot smell it and a respirator is needed?
thx
It depends on what the stuff is,what warnings does the product itself give.It usually comes down to amout of exposure and time of exposure.Are you well ventlated,are you spraying clouds of it for large amounts of time,or are you mixing small amonts and applying it to your model with a small paint brush for a few minutes.
You are probably okay,but consider the products warnings,your amount of exposure,and your own tolerances
Basically, odorless is just that, no smell. It still evaporates and gets inhaled to your lungs but as Anthony points above toxicity depends on you, how you use it, etc.
thx guys. I actually missed to mention that I am using it to dilute oil pants that I hand brush for weathering, and keep some on the side for cleaning.
For spraying I have my spray booth setup no worries there.
FWIW - I like to place model in my spray booth for the weathering with washes process. Running the fan to ventilate just like when airbrushing clears any fumes from mineral spirits or naptha/cigarette lighter fluid very nicely.
What is in a word?
Odorless = no smell. Smell and toxicity is not the same
Drastic example: Carbon monoxide is also odorless, but too much of it will kill you …
As Tojo72 wrote: “It depends on what the stuff is”
Just for the fun of it, here is the Material Safety Data Sheet for Gamsol (just one of many odorless thinners)
Gamsol data sheet
Section V - Health Hazard Data brings us this cheerful message:
To be honest, I definitely prefer a stinky solvent/thinner which keeps me aware of the presence of it.
If I can see, smell or hear “danger” I can avoid it, odorless will creep up on you
Which product/products are you using?
An excellent question and thanks for asking it !!!
I use it pretty much as you do George.
I survived 40 years in the printing industry and there were some nasty chemicals we used every day.
There were a few times I caught a buzz from a chemical called Fedron. A high then a nasty headache followed. Ahhh… memories !
thx guys!!!
@Uncle-Heavy I have the AK odorless thinner (AK050) and white spirit (AK047), and Mig odorless thinner (A.mig-2008).
I didn’t manage to find any data sheets for them, AK recommends reading the labels on the bottles.
Since one is a turpentine and the other a white spirit, both are solvents, I would treat them as turpentine and white spirit. Use with good ventilation and/or respirator. The small amounts we use also limits the exposure, painting for several hours per day versus at the end of a long building project.
Use a repirator, it won’t hurt, whereas not using one may have ugly, and painful consequences 5-10-20 25 years down the road
I was outside in my wide open fresh air car port spraying a couple of Tamiya rattle-can test strips. Even still, at minimum, l had to wear a mask. I’ve always been very sensitive to airborne particulates. 
—mike
I did some digging and here are the results, and the hopeful message 
:
Now comes the interesting part: I did some research on the safety levels for both of them, and it seems that white spirits are “safer” than turpentine (even though turpentine is considered a “natural” product):
I am going geeky now but bare with me:
The exposure limit (PEL) for turpentine is <100ppm (525-590 mg/m3). For example in US(OSHA) the limit is below 525mg/m3, while in UK is <590mg/m3). The exposure limit for white spirits is 500 ppm (2900 mg/m³).
Ppm stands for parts per million and that is just a unit of concentration and one ppm is basically one millionth of the total vapor volume.
The PEL or permissible exposure limit is the amount of exposure a worker is allowed to be subject to in (commonly) 8 hours . Any more exposure than that over an 8 hour period must be mitigated or reduced in some form.
Talking the Turpentine solvent which is the worst of the too as an example, this means that in case one is working in a normal room of 4x3x2.2=26,4m3 the PEL is 525*26,4=13.860mg/26,4m3. This translates to 16,116ml of Turpentine, that we should be using to be in the danger zone.
For white spirits the limit is way higher (76.560mg/26,4m3, or 96,1ml)
Now in my case, which is the case for most of you, I do not use more than 4ml when I do my weathering, so it seems we are safe… I still wear my respirator though
References:
Turpentine
White Spirits, White Spirits 2
White spirits Hazard labels: Interesting about this document is the Hazard labels of white spirit products (note, the AK white spirit has only the H304, which means it is one of the softer WS solvents).
I hope this is helpful and will bring some ease of mind to restless spirits like me 
Note: One aspect I could not scientifically confirm, is that odorless Mineral Spirits are heavily refined to remove as many harmful pollutants as possible so the formulation doesn’t negatively affect respiratory health. This could mean that the AK odorless thinner (turpentine) has potentially higher PEL than standard turpentine.
