Are there any woods NOT suitable for food use?

[Odie]

The question is self explanatory, but I'd like to know your reasons for not considering certain woods suitable for salad/food bowls.

Also, if there are some you consider superior, I'd like to hear your reasoning about that, as well.

I have not made a lot of food-safe bowls, but intend to do a few more in the future. I'm using the General Finishes, Salad Bowl Finish. 3 coats, wet sand after first coat, steel wool after second. This sound about right to you?

Thanks

otis of cologne

 

[MichaelMouse]

There are certainly some which are worse choices than others. Open-grained stuff is an invitation to diarrhea, because it provides a lot of places for the bad guys to hide. I would also be wary of those durable woods loaded with fungi/insecticides. If you leave stuff sitting in them, they might leach enough to affect the sensitive.

You're using a varnish finish, which will minimize either of the above concerns, but what the hey, there's enough beech/birch/maple and cherry stock with low toxicity out there to work with. Nice close-grained stuff in lighter colors is what I like. Just oil and burnish, because they'll have plenty oil added later if they toss in the bowl, or urethane for me.

 

[Owen Lowe]

Cascara and Camphor
are two that I'd not wish to try with my porridge.

 

[Wyatt Holm]

Poison ivy> well that might not quite be wood but it would not be good.

 

[n7bsn]

I tend to stay away from tropicals and "known nasty woods". Normally "nasty" woods are woods that are highly resistant to insects and rot. The wood has developed toxins to protect the wood, these toxins -might- not be a good idea for us either.

Recently I was comparing the "normal list of toxic woods" (published in a number of woodturning publications). To a list from the UK's Health people, and some other lists. One thing I noticed is none of the lists included any fruit woods. I suspect this is due to a fruit wood needing the "fruit" to be edible and plants finding it hard to make the fruit "good" and the wood "bad".

The other thing I noticed is that the only listing for Maple, specifically noted a mold, not the wood.

So, I guess my first recommendation might be fruit woods and/or non-spalted maple.

TTFN
Ralph

 

[Vaughn]

Cascara and Camphor
are two that I'd not wish to try with my porridge.

I'd tend to agree, but I did sell two big camphor salad bowls to a chef once. They were finished with just mineral oil, and were still plenty aromatic. He bought them because of that.

 

[MichaelMouse]

Recently I was comparing the "normal list of toxic woods" (published in a number of woodturning publications). To a list from the UK's Health people, and some other lists. One thing I noticed is none of the lists included any fruit woods. I suspect this is due to a fruit wood needing the "fruit" to be edible and plants finding it hard to make the fruit "good" and the wood "bad".

They defend their leaves and bark with noxious chemicals, that's for sure. http://www.vet.purdue.edu/toxic/plant46.htm Keeps them alive and feeding. Reproductive strategies of trees in relatively constant environments like tropical forests will differ, I should think, from those where a single night of frost can destroy all reproduction for a year.

 

[Rob Wallace]

Any of the woods known to cause contact dermatitis should be avoided....

This includes woods such as cocobolo and other "Rosewoods" of the genus Dalbergia (Family Fabaceae/Leguminosae). Leaching of chemical compounds such as dalbergines into the food could cause serious medical/health problems for users of your utilitarian pieces. The comment about poison ivy (which actually does produce true wood) is relevant, since woods in this family (Anacardiaceae) are also known to produce dermatitis in sensitive individuals; stay away from mango, cashew, sumac, goncalo alves, quebracho and related woods.

There are 5 links to toxic wood references listed HERE - have a look at potentially toxic species. Unfortunately, many of these lists are incomplete, and I am slowly compiling a more complete and detailed list of toxic wood species for turners and other woodworkers, but digging through the literature is very time consuming and sometimes tedious and disappointing, due to incomplete information available.

The comments about the harboring of various bacteria in porous, open-grained woods should also be heeded. Close-grained (diffuse porous) woods such as maple, beech, cherry, etc. are best candidates.

Turn safely!

Rob Wallace

 

[Gretch Flo]

Oak?

What about oak?? Gretch

 

[Odie]

What about oak?? Gretch

Certainly, I'm no expert on this subject, but as long as oak is sealed and not subject to liquids penetrating beyond the surface, I'd think it would be OK for food us.......but, my opinion is worth what you paid for it! Ha!

ooc

 

[Bill Boehme]

What about oak?? Gretch

That would most definitely apply to oak. While oak is not toxic, most types of oak have large pores that are good places to trap food residue (red oak is the worst). Coastal live oak does not have large pores, but is hard to find and, in my experience must be turned green because it is rock hard after it dries. There is good reason that it was used for the keel and other structural members of sailing ships.

 

[hockenbery]

Barrels are made from white Oak to hold and age
all sorts of consumables. Very rot resistant too.

Can't make barrels from red oak the leak.
the red oaks have the big pores.

al

 

[Owen Lowe]

Barrels are made from white Oak to hold and age
all sorts of consumables. Very rot resistant too.

Can't make barrels from red oak the leak.
the red oaks have the big pores.

al

Pore size isn't the determining factor between red and white oaks. The white has an abundance of a substance called tyloses in the pores. They look like whitish crystals and function as barriers to liquid flow. Red oak has much fewer of the tyloses and thus isn't liquid tight for containers.

An old-timers trick to tell white from red is to try blowing air through the end grain. Red oak will allow your breath to pass through while white only gives you that fetching Dizzy Gillespie look:
http://growabrain.typepad.com/photos/uncategorized/dizzy.jpg

Owen

 

[robo hippy]

Owen,
I know what happens if you chew on the cascara (chittum) bark, but never had any trouble with the wood. For those who don't know, a lot of people here in the northwet would peel the bark from the chittum trees, and sell it to drug companies as an ingredient for laxatives.
robo hippy

 

[John Nicholas]

Sanitation and Wooden Cutting Boards

http://faculty.vetmed.ucdavis.edu/faculty/docliver/Research/cuttingboard.htm

Get a university research project's perspective on wood and sanitation. The article does a good job of presenting these facts.

Any close grained hardwood.

Also, when selecting a wood, one should give some thought to care of the bowl by the end user. Dishwasher, mashed potatoes, fruit on a table; serve green beans. The use intended may reflect a need for different woods. That may also reflect a need for different design considerations.

John

 

[Bill Travelstead]

Commercially I've only seen maple and cherry used for counters, tools, cutting boards and bowls. Recently I've seen accacia advertised and used on the Food Network for cutting boards.

So it would seem that historically maple and cherry are the preferred woods.

 

[Gretch Flo]

oak butcher blocks

Haven't I seen oak for butcher block tables?? Gretch

 

[Rob Wallace]

Haven't I seen oak for butcher block tables?? Gretch

Gretch:

What woods you see used for butcher blocks that are available for sale, and what's a truly appropriate wood for cutting surfaces of butcher blocks may be two different things. If manufacturers are using oak for the cutting surfaces (especially end-grain) they are doing a dis-service for the reasons noted above about harboring bacteria, etc. in the wide pores of oak (especially red oak). Although the tyloses found in white oak will reduce the porosity a bit, the early wood cells in white oak are still large and can harbor microbes, which are potentially hazardous from a food-safe perspective.

If the actual cutting surfaces were made of a dense, diffuse-porous hardwood like maple or beech, it wouldn't matter what wood was used for the butcher-block support, etc.

Rob Wallace

 

[Dave Roller]

Hey, them bacteria are itsy, bitsy! And can harbor in the closest of grain woods! I think Odie has it about right--what is key is how the wood is sealed. And, how the article is to be used. I wouldn't worry about a, say, wooden spoon, because they are usually used in high temperature situations.

 

[Owen Lowe]

If you haven'd done it yet, read the link John Nicholas posted to a study done at UC Davis Food Safety Lab. The wood porosity is apparently what makes wood a better choice than plastic over time. The bacteria are drawn into the wood, away from the surface and die. A scored (used) plastic cutting board held the bacteria in the knife scores and on the surface.

http://faculty.vetmed.ucdavis.edu/faculty/docliver/Research/cuttingboard.htm

A portion of the article (I added the bolding to the text.)

In addition to our laboratory research on this subject, we learned after arriving in California in June of 1995 that a case-control study of sporadic salmonellosis had been done in this region and included cutting boards among many risk factors assessed (Kass, P.H., et al., Disease determinants of sporadic salmonellosis in four northern California counties: a case control study of older children and adults. Ann. Epidemiol. 2:683-696, 1992.). The project had been conducted before our work began. It revealed that those using wooden cutting boards in their home kitchens were less than half as likely as average to contract salmonellosis (odds ratio 0.42, 95% confidence interval 0.22-0.81), those using synthetic (plastic or glass) cutting boards were about twice as likely as average to contract salmonellosis (O.R. 1.99, C.I. 1.03-3.85); and the effect of cleaning the board regularly after preparing meat on it was not statistically significant (O.R. 1.20, C.I. 0.54-2.68). We know of no similar research that has been done anywhere, so we regard it as the best epidemiological evidence available to date that wooden cutting boards are not a hazard to human health, but plastic cutting boards may be.

 

[Frank Kobilsek]

Rob,

I know the cashew story - that the shells are very dangerous, but what is the story with Mango? I got a Mango log at a turning auction a couple years ago and just rough turned a couple bowls from it this week. It had a nice spalt to it, which I don't know if weas in there when I bought it or developed as it lived on a wet spot in the garage. Along with the bolw rough out I have several box blanks from this log.

Frank

 

[robo hippy]

Just remembering, but Laburnum (Golden Chain) is supposed to be bad, all parts, flowers, leaves, stems, bark, wood, and roots.
robo hippy

 

[Gretch Flo]

Longevity of sealer

Hey, them bacteria are itsy, bitsy! And can harbor in the closest of grain woods! I think Odie has it about right--what is key is how the wood is sealed. And, how the article is to be used.

As mentioned in previous threads, over a period of time the finish may get eventually washed/worn off. Does this apply to sealer????? Gretch

 

[Rob Wallace]

Rob,

I know the cashew story - that the shells are very dangerous, but what is the story with Mango? I got a Mango log at a turning auction a couple years ago and just rough turned a couple bowls from it this week. It had a nice spalt to it, which I don't know if weas in there when I bought it or developed as it lived on a wet spot in the garage. Along with the bolw rough out I have several box blanks from this log.

Frank

Frank:

The connection with mango is that it belongs to the same plant family (Anacardiaceae) as poison ivy, sumac, and other species that are known to cause dermatitis and other allergic responses. These were mentioned as a "caution" for woods that might not be recommended for contact with food, given that in sensitive individuals, health concerns might develop. If the wood you mention (or for that matter, any wood) is truly spalted, I would not recommend it for use with food. Those who favor the "seal it and use it" philosophy would differ, but with so many woods available for which there are no major problems known, why risk problems when you can decide to avoid them altogether?

Rob Wallace

 

[Odie]

As mentioned in previous threads, over a period of time the finish may get eventually washed/worn off. Does this apply to sealer????? Gretch

Hiya Gretch......

I would think that all depends on how deep the sealer penetrates the wood. Things like room temperature when the sealer is applied, the wood species, and brand of the sealer probably make a difference, too........


Here's a related question:

I've been using General Finishes "salad bowl finish", and the final product is kind of dull looking. Would it be ok to apply some Carnauba wax to the salad bowl finish? I expect the Carnauba to not last at all, but it might make a salad bowl more saleable.........OK, or not?

ooc

 

[MichaelMouse]

Hey, them bacteria are itsy, bitsy! And can harbor in the closest of grain woods! I think Odie has it about right--what is key is how the wood is sealed. And, how the article is to be used.

As mentioned in previous threads, over a period of time the finish may get eventually washed/worn off. Does this apply to sealer????? Gretch

Bacteria do not care about pore size, except that they generally require help to get around. Even the ciliated types appreciate a film of water persisting in a nice pore to finish their life cycle and form spores. If there's some semisolid food stuffed in the space in addition to moisture, there'll be a lot more spores available for transport when the wood gets wet again.

So a sealer that stuffs pores will continue to help even when the surface finish is gone. Or, in the case of stuff I do, there is no surface finish. I stop at first shiny coat of wipe-on poly and wet sand the film off. Carnauba or any other wax is going to be vulnerable to the ultimate salad bowl finish - salad oil - where the salad is dressed in the bowl, so it's sort of false advertising to put it on at all. It will also water spot without prompt care after dampening.

I just tell folks to rinse after use, and then to wipe the interior with a towel dampened with vinegar prior to next use. Decent antibacterial.

 

[Gretch Flo]

temporary finishes

Hiya Gretch......

I've been using General Finishes "salad bowl finish", and the final product is kind of dull looking. Would it be ok to apply some Carnauba wax to the salad bowl finish? I expect the Carnauba to not last at all, but it might make a salad bowl more saleable.........OK, or not?

ooc

That's the point I want to avoid-making it look good and having the buyer or gift recipient be dismayed that it doesn't look as good with a few washings. Min oil beeswax makes it look alot nicer so I avoid for sale items. I have however made my own (5 pts beeswax to 3 pts mineral oil) poured into crystal lite (I drink alot of that!!) 2 oz plastic tubs. Cover with Press and seal wrap. Give away with purchases of $50+.
I too didn't like the end result of salad bowl finish. Still not satisfied on some woods with gen Finish's Danish oil, nor Mahoney's walnut oil, or a combination. Looking for something easy to apply that gives a uniform satin sheen that stays -wistfully hoping for permanency. Gretch

 

[Odie]

That's the point I want to avoid-making it look good and having the buyer or gift recipient be dismayed that it doesn't look as good with a few washings. Min oil beeswax makes it look alot nicer so I avoid for sale items. I have however made my own (5 pts beeswax to 3 pts mineral oil) poured into crystal lite (I drink alot of that!!) 2 oz plastic tubs. Cover with Press and seal wrap. Give away with purchases of $50+.
I too didn't like the end result of salad bowl finish. Still not satisfied on some woods with gen Finish's Danish oil, nor Mahoney's walnut oil, or a combination. Looking for something easy to apply that gives a uniform satin sheen that stays -wistfully hoping for permanency. Gretch

......and, that's a point well taken, Gretch.

I wonder how many people actually expect their used salad bowl to remain as good looking as when first purchased......? Undoubtedly there are some, but these are probably among those who can't/won't be satisfied about many things in life that they should! I'm half tempted to say it's too bad they are disappointed, and welcome to reality!

As far as using a little Carnauba to enhance the looks of a new salad bowl.......do you believe there is something dishonest, or unethical about doing that? Carnauba is food safe, isn't it?

That's a great idea you have about including some of your favorite beeswax/mineral oil with a bowl sold. (That could also be used as a "selling tool" in the right situation!) I have been telling people to just apply a coating of cooking oil after each use. This is what I've been doing with a cutting board I have that has been used for about 25yrs in my home......and although it's got lots of knife cuts, it still looks very good!

Yeah, you and me both! Sure would like to get a fabulous finish on a salad bowl that looks....and STAYS great!

BTW: Here's a pic of a Cocobolo bowl I saw on ebay. This has about the most gorgeous looking finish I've ever seen!.....and it's advertised as "food safe", but doesn't mention what the finish is. It's made in Costa Rica and imported here. Check this out!

ooc