A whiter shade of pale
Evan Zabawski | TLT From the Editor August 2012
Milking an answer for all it’s worth.
The same ingredient that whitens milk is also used to whiten paint.
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WHILE AUDITING A HEAVY-DUTY MAINTENANCE SHOP, I WAS ASKED A SIMPLE QUESTION THAT REQUIRED AN EQUALLY SIMPLE ANSWER, BUT EVOLVED INTO AN INTERESTING DIGRESSION. The question came about after I viewed their large-scale parts washer that employed an aqueous cleaning agent. I stated that without a secondary rinse, there was a strong possibility that residual cleaner might show up in the oil analysis results. My guide then asked if lead from aerosol paint would also show up in the oil analysis results since they repainted their equipment in the adjacent paint booth.
I playfully answered, “I hope not. You shouldn’t even have lead-based paint. It was banned decades ago.” He quickly realized the folly of his question and laughed, too, but I then stated he was onto something. I then asked him if he knew what made white paint white (their company color happened to be white). When he said he didn’t know, I went off on a tangent and have repeatedly used this tale in my training seminars.
I always state that people who attend my training will learn three things about the dairy industry that will forever change how they view dairy products. First, butter is synthetic—a full explanation can be found in my July 2010 column. The second involves the preceding tale and its conclusion.
The beginning of my tangent recounts my desire to have a healthier diet resulting in a switch from drinking 2% milk to skim milk (aka fat-free milk). Usually the discussion really digresses for a moment while others share their experiences and declare they didn’t like the taste of skim milk at first. Not only does removing the fat change the taste, but it also removes a lot of the whiteness, causing the milk to be an unappetizing bluish- grey color.
A key aspect regarding accepting skim milk into your diet begins with appearance, and this is recognized by the dairy industry, which is why they add a pigment to restore its whiteness. The same ingredient that whitens milk is also used to whiten paint. It is also used to whiten cottage cheese from its naturally yellowish color. I can’t decide if that really is more appetizing or if I would prefer it to actually resemble other cheeses.
The pigment employed by both the dairy and paint industries is titanium dioxide. It works due to its very high refractive index, making products whiter, brighter and even reflective. Titanium dioxide is the most widely used pigment and is also used to color paper, plastic, medications, cosmetics and toothpastes. Changing the size of the pigment particles allows it to be used to provide opacity in many of the same products. When coated with alumina or silica, titanium dioxide becomes the key ingredient in sunscreen, where it is able to absorb ultraviolet rays without photocatalyzing carcinogenic free radicals.
I hope I haven’t put anyone off skim milk, now that you know it is pigmented with the same ingredient used to pigment paint and is the key ingredient in sunscreen.
Returning to the original question about lead showing up in the oil analysis report, the answer is still no; however, it is possible to find titanium. These particles could be from excess aerosol paint that does not bond to the metal surfaces or could evolve from loose paint chips being milled into very small particles over time. Realistically, finding titanium in oil analysis results usually indicates wear from titanium alloyed steel parts, but keep this alternate source in mind.
So what’s the third thing to learn about the dairy industry? I’ll leave that for another column.
Evan Zabawski, CLS, is the vice president of technical services for CAN-AK/IAS in Calgary, Alberta, Canada. You can reach him at ezabawski@can-ak.ca.