Ask the Expert Question-and-Answer Archive

by Ron Joseph

January, 2001

Paint Particulates in Spray Booths

Q. I am an engineering student who is developing a computer program to help in the preparation of an Air Permit Application for a coatings operation, i.e., spray paint booth. I would like to know if there exists a list of Common Particulate Species, i.e., titanium dioxide, that are found in coatings?

A. To the best of my knowledge there is no list of particulates that you will find in a paint spraybooth. However, if you were to call the paint companies that supply paints and coatings to the operation you referred to, they can give you a detailed list of the ingredients that the paints are comprised of. This includes the resins, pigments, extender pigments and paint additives. Many paint and coating companies will not provide the information in such detail, but perhaps if you tell them of your project they might be willing to help you.

Why do you need such detail for the permit application? Frankly, the most important information for permitting purposes is the presence of hazardous air pollutants, (HAP), and here chromates are among the most important solid components. Titanium dioxide is not a HAP and I don't see why you need this for a permit application. If there are EPA reportable ingredients in the primers and topcoats, they will be listed on the MSDS.

I am interested to hear more about your computer program project.

Camouflage Paints

Q. I am interested in information pertaining to paint or ink that will stand out when viewed through special eyewear such that when viewed at a distance an item with the paint or ink applied will jump out at the viewer. The paint need not be invisible. I would appreciate any help you can give me.

A. There are indeed paints that, when viewed under different light sources, can jump out at you. Specifically, camouflage paints that are used by the military have one appearance and color when viewed in broad daylight, and a completely different appearance when viewed under infrared light. However, in order to see them you need to shine an infrared beam on the object, or use natural infrared light. This is how the military is able to spot non-camouflaged military hardware at night from high flying aircraft or satellites.

Since I don't know what you intend to do with your application I can't help you further, except to suggest that you call the chemists at some of the large paint companies, such as Sherwin-Williams, Deft Inc., Spraylat, and more. All of the companies that I've mentioned make camouflage paints for the military, and should be able to advise you further on the types of pigments that are available.