January 2015 Meeting
- Written by Chuck Jones
West Tennessee Woodturners met January 10, 2015, at Jackson State Community College. There was a good turnout with twenty-one members and three guests braving the cold weather to attend. Bob Hobbs presided at the meeting.
The door prize was $25 contributed by Bill Wyche and was won by Jim Tusant. The wood exchange was not held due to the cold weather.
Bob announced that the program for February will be Norman Fowler demonstrating the proper use of the bowl gouge. Norman's skills with the bowl gouge are highly regarded and this will be an excellent opportunity for all of our several newer members to pick up lots of points about bowl turning. Some of us long term members who didn't pay close attention the first time will gain some good information as well.
For February the challenge will be "Two Identical Items". Start early. Don't be fooled into thinking it's easy. That's why it's called a challenge.
- Written by Emmett Manley
Woodturners often encounter and even ask this question -- is this wood finish food safe? The answer is almost certainly yes, especially when you remember that food safe is different from food friendly – a few drops of linseed oil or turpentine won’t harm you, but the flavor of your food may suffer. If people would just think for a moment, they would realize that only an infinitesimal quantity of finishing material could possibly be ingested with each use of a bowl.
The tiresome phrase “finishes are safe if dry” had to be written by some bureaucratic intern at the FDA. Who is going to eat cereal out of a bowl still wet with a coating of polyurethane gel? And what would happen if you did? It would be a challenge to find a wood finish that produces significant toxicity in such small doses.
In a previous life, I was a pharmacologist who spent a lot of time evaluating the toxic potential of substances foreign to the body. Drugs and other chemicals differ in terms of the type of toxicity which may be produced and in the amount required to produce that toxicity. Which brings us to the critical factor of DOSE. As Paracelsus (circa 1530) stated: All things are poisonous, for there is nothing without poisonous qualities; it is only the dose which makes a substance a poison. Cherry wood and apricot pits contain cyanide, one of the most toxic chemicals found in nature, but the amount of cyanide is too small to produce problems under most circumstances. On the other hand, drink enough water -- several gallons -- and it will kill you.
With each use how much shellac, lacquer, wax, etc. could be ingested from a wooden bowl that had been finished with such a product? One milligram? Probably less than a microgram. Let’s take an extreme case. Rather than ingest a tiny amount of shellac with each bowl of cereal, what if we swallowed the amount of shellac covering a wooden bowl in one gulp. What would happen? Not much. And you won’t be consuming all the shellac at once, probably a small percentage even over decades of regular use. A similar situation exists for most other common finishing chemicals. If a tiny bit should be absorbed it is comforting to know that most foreign chemicals are quickly removed from the body, typically by some biotransformation in the liver, followed by elimination in the urine.
Also, most ingested oils and waxes are not absorbed by the body to an appreciable extent; in fact, long chain hydrocarbons (mineral oil, petroleum jelly, paraffin, etc.) are used as lubricant laxatives because they pass right through the gastrointestinal tract. The laxative dose of such oils is measured in grams, not milligrams or micrograms.
How did all this concern about containers being food safe get started? Remember I said most foreign chemicals are quickly eliminated from the body. Well, there are a few exceptions and heavy metals constitute a major exception. Lead, for example, accumulates in the body when ingested over a period of time. And, it does not take a lot of lead to produce serious toxicity to the brain, heart, kidney, and just about every other critical organ in the body, especially in children.
About 75 years ago there was a rash of toxicities reported in people using unglazed lead-containing pottery from Mexico. Daily consumption of acidic beverages (orange juice, etc.), leeched lead from the pottery, and over a period of years, resulted in irreversible and serious neurotoxicities, including developmental disorders, seizures, coma, even death. More recently there has been legitimate concern about lead based paint pigments and such paints have been banned in the U.S. since 1978. Lead was removed from gasoline because of the same concern.
If you want to worry about food safety – think about the last person who used your fork at your favorite restaurant. Did they have hepatitis? Was the tableware really sterilized in the dishwasher? Did the kitchen guy making the cold salads have E. coli smeared all over his hands? There is a lot to worry about relative to food safety, but a few micrograms of polyurethane in your cereal is not one of them.
A postscript for the professional woodturner. If you are trying to sell “food safe” products, you have to respect what customers believe, even knowing that they are wrong. It is not worth the time to try to educate folks who are so caught up in the green, organic, and natural world that they are totally opposed to any “chemicals”. Therefore, you may be forced to use mineral oil, beeswax, walnut oil, or other perceived “natural” finishes to make a sale. Or, use no finish at all, but most people want shine!
NOTE TO READERS: THIS IS A TWEAKED ENCORE ARTICLE FROM 2009