Building Frames and Gold Screws

Hello-

My husband is building our frames. He is using Gold Grip Rite screws from Home Depot to put the frames together and to attach the plywood to the bottom of the frames. We looked at what gold zinc is and it is a chromium plated zinc that looks gold.

From a poisoning point of view, we are concerned that chromium and zinc in the screws would leach out into the soil would hurt the plants and then us. Does anyone have any thoughts on this subject? What kind of screws did you use when building your frames?

Thank you for your thoughts on the subject.

Respectfully,

Mary S.

We used just regular old deck screws. I don't think leaching from screws/nails is too big of a concern but... WHO KNOWS? I can't imagine what you could attach the boxes together with if you chose not to use screws/nails. I wonder what the opinion is of the more experienced SFG'ers.

Hi-

Thanks for your reply. We want to use screws, just something that isn't made with chromium. We like the idea of organic gardening, but introducing heavy metals seems like we are defeating our purpose.

Mary

my view is that the screws are going into the wood. will not touch the soil. by the time the wood rots away and exposes the screws, you're going to have discovered a better way to put the boxes together.

ooh, check out the sfg store! they have some neat boxes for sale. some are made by amish and are real pretty!

i consider my gardening organic even though i use 'normal' deck screws.

i am intrigued to see what other folks think though and will be bookmarking this thread to follow along.

i'm open to changing my ways if 'shown the light' on a better way. *grin*

I thought I'd do a little searching, and I found an interesting website about chromium (note that it is a cdc.gov website, so it's pretty trustworthy.):

http://www.atsdr.cdc.gov/tfacts7.html

In short it outlines the ways that high levels of chromium do cause cancer, but on the other hand the body does require it to perform some functions (in small doses). From what I could tell, if it got into the food it would be chromium III which is one of the safest forms.

With that small amount of research, I'd agree with happyfrog: the screws are going into the wood, not the soil. So it's probably safe. On the other hand, there's certainly no harm in getting some regular old stainless steel screws.

You probably have screws that are harmless, with clear zinc plating with yellow chromate as a top coat. This coating is only about .0002" thick or less. You don't want to purchase ANY fasteners with yellow cad plating, (cadmium) as it can be absorbed through the skin. The US military is moving away from all fasteners that have cadmium plating and are using a lot of commercial grade 8 fasteners.

If you are concerned, get the MSDS (material safety data sheet) sheet on the product from your supplier. All US suppliers have them or can get them and should supply them at no cost.

When I said at the end that you could just go with regular old stainless steel screws, it got me wondering, "what's in stainless steel?" My last post was a little rushed (I was on the way out to visit family), so I couldn't look into it at the time. I just got back and I just did some more searching, and I found that the one requirement in stainless steel is to have ... chromium. It turns out that it's the chromium that keeps the stainless steel, well, stainless. (Which I'm guessing is why it's on those fancy screws of yours.) Now I know that there are grades of stainless steel which are actually used in surgeries for permanent implants (steel rods, etc) and they aren't worried about it messing up the body. So I'm sure that you're fine using them in your boxes.

As a side note, I personally didn't put this much thought into the screws I used for my boxes. I just used whatever leftover deck and drywall screws I had. They work.

Many thanks to all who replied. I appreciate your input and research.

Mary

I would expect that any leaching would be extremely minimal. Probably so low that the change in the chromium concentration on the soil nearest the screws vs those farthest from the screws would be undetectable.

I don't have any research to back this up, but it's like others said, those screws are not really going to be in contact with the soil.