Re: How can I measure nail polish for flammability?

Now then - flammabilty of nail polish - thats a tough one for many reasons. 
Firstly, we won't doubt that nail polishes are considered "Flammable" which is 
level 3 on a scale of 0-4 (for a good explanation of each catagory see this 
link).
 
The polishes are considered flammable due mainly to the solvents used in 
the polish. These solvents, as you are probably aware, are usually ethyl 
acetate, isopropyl alcohol or butyl acetate. 

These three solvents are used in nail polishes as they have a good (ie. 
high) %vapour/volume values. So what do I mean by this?  It means that at 
any time a certain percentage of the solvent exists as vapour above the 
liquid solvent, which in this case is in the polish. So thats why you blow 
across your nails to dry them faster, this blowing is removing the solvent 
that has evaporated and is sitting above your nails as a vapour. Removing 
this vapour to the atmosphere allows further solvent from your nails to 
evaporate from the liquid polish and after awhile, all of the solvents have 
evaporated, leaving your nails coated in coloured polymer (plastics).

Flamabilty ratings for chemicals such as the solvents found in nail polish 
are determined from chemical properties of that particular chemical. The 
main factors are flash point and volatility. All of the nail polish 
solvents have low flashpoints (see above link, for explanation of 
flahspoints) and are fairly volatile, so really the only way to determine 
the "flamabilty" of a particular brand of nail polish would be to determine 
the amount of flammable material in it.

I simple test you could do is to take a small glass jar, with screw-top 
lid, and quickly smear a line of polish across the bottom of the jar and 
then close the lid tightly. After waiting a certain length of time 
(dependant on the size of jar and amount of polish applied) some of the 
solvents will have evaporated and now be as a vapor in the sealed jar. 
Quickly openning the jar and placing a long barbeque style lit match above 
the jar top or placing the long match just inside the jar should ignite the 
vapourised solvent. Perhaps, after say 1 minute or 30 seconds, a polish with 
low solvent content would not ignite whilst one with higher solvent content 
would, and by this you could state some sort of flamabilty rating.

Just on safety, make sure you never expose nail polish itself to a lit 
flame or high heat, the solvents in the polish would most certainly ignite -
most likely causing the coloured polymers to catch alight as well. Burning 
polymers and the solvents themselves can release posionous gases such as 
carbon monoxide so be careful when and where you perform such experiments.

Good luck with the fair.