Rust vs Galv vs BPA's

[TapME]

Dr.Perkins, This rust subject has come up a number of times here, and the galvanized debate still goes on. I have a request to make if you can fill it. 1 Could you post findings on aluminum transfer into syrup(we all know about aluminum poisoning)vs galv into syrup from sap being in these containers(not lead that's another subject). 2 Post the findings of lead transfer from galv buckets into syrup and how that differed from non galv buckets(aluminum and or plastic etc). 3 could you post the findings about food grade plastics and the release of BPA's into the contents from the containers. Thanks for your time. TapME

[Clan Delaney]

Moving this reply to it's own thread at the poster's request.

[DrTimPerkins]

1 Could you post findings on aluminum transfer into syrup(we all know about aluminum poisoning)vs galv into syrup from sap being in these containers(not lead that's another subject). 2 Post the findings of lead transfer from galv buckets into syrup and how that differed from non galv buckets(aluminum and or plastic etc). 3 could you post the findings about food grade plastics and the release of BPA's into the contents from the containers. Thanks for your time. TapME

1. Little is known about aluminum transfer into syrup through sap. There is likely very little (if any) measurable aluminum in uncontaminated sap straight from the tree. We have looked at aluminum concentrations in syrup, and there doesn't seem to be any problem. The association between aluminum in food and health effects is very tenuous at best except in extreme cases. However, the maple manufacturer's guidelines are to limit aluminum in maple equipment where possible.

2. Pre-1994 galvanized buckets, particularly the really old ternplate buckets or lead soldered buckets can be significant contributors of lead to sap, especially during slow weeping flow periods when buckets are not emptied frequently. Plastic buckets obviously do not leach lead into buckets.

3. Nearly all plastics will contribute some compounds into sap. In terms of BPA, the new styles of polyethylene tubing and food-grade nylon (spouts/fittings) are typically BPA free. BPAs typically originate from polycarbonate plastics, PVC, polystyrene, and epoxies...which are not terribly common in most sap collection materials. There is unlikely to be a high amount of BPA contamination in sap.

Tim Perkins
UVM PMRC

[TapME]

Thanks doc. I was looking for more concrete info on the subject of lead and aluminum transfer and BPA's. In my mind if it's made from plastic(oil with chemicals in it) it has to be leaching something into the sap. You just don't have a test for it yet or its not been brought to our attention. As for the lead I was looking for PPM info. And could you base that on the US standards for allowable PPM in foods. (drinking water comparisons would be nice to have also)
I would like everyone here and especially those that have there syrup tested and it passes the state and fed guidelines on lead in PPM and hobbyist know that it is OK to use that old pan and feel good about it. We just have to remember that we are not drinking out of lead cups and killing ourselves slowly as the Romans did. Whats next in 20years stainless has a bad leaching effect on causes us to grow a second something?

[DrTimPerkins]

Thanks doc. I was looking for more concrete info on the subject of lead and aluminum transfer and BPA's.

I could probably write a book on lead (we did 6 yrs of research on that topic), a paper on aluminum (related to some work we've done on metal contamination of syrup), and a couple of sentences on BPA (one study on plasticizers). This is not the place for any of those, except perhaps the latter, for which there is exceedingly little information available.

If you have SPECIFIC questions, write me off-list (Timothy.Perkins@uvm.edu) and I'll try to answer them. Don't just ask me to tell you everything I know about lead, because I just don't have time to write that book right now.

The bottom line is probably that it is extremely unlikely that you could consume enough syrup for either aluminum or BPA to be a health issue, and it would be darn hard with the vast majority of maple syrup. It is only in some very specific instances with extremely high lead levels in conjunction with high consumption levels of syrup that you might run into a problem.

Tim P.
UVM PMRC

[Haynes Forest Products]

Didnt they try and scare everyone half to death with rumors that cooking food in aluminum pot's caused Alzheimers? I go to a resturant supply and they have pots from 1 quart all the way up to 160 quart pots all made of aluminum. You start making tomato sauce in them babbies and will all be forgetting our names:lol:

[KenWP]

The problem with aluminium is that it can melt real quick in a arch if it ever was with out water,sap syrup etc. My first idea was to use a big A pot as it was pretty cheap compared to SS untill I figured out the pot wasn't big enough and second wasn't tough enough. Since aluminium is the most common metal in our soils as it is we get a good dose of it in our water and food every day anyways. The tiney bit from cooking is small compared to what we get with out trying.

[DrTimPerkins]

Since aluminium is the most common metal in out soils as it is we get a good does of it in out water and food every day anyways. The tiney bit from cooking is small compared to what we get with out trying.

Aluminum, like several other metals, is not readily picked up by plants and translocated in the sap stream (unless the soil is quite acidic -- not typical of agricultural crops). Thus it does not accumulate in plants. Any aluminum (or lead, or cadmium, etc.) you're getting from plants is most likely due to surface contamination (dust, soil) if the crops aren't washed well.

Cooking and storage in aluminum containers is probably a higher contributor to lead in the diet than plants. This is especially the case with acidic foods. Most GOOD aluminum cookware is anodized (hardened), so aluminum transfer into food is greatly reduced.

The LMEA (Maple Equipment Manufacturer's Association) voluntarily limited the use of aluminum in maple collection and processing equipment. Better options exist in most cases.

All that said, my personal opinion is that the health threat from aluminum from cooking pots is quite low. The link between alzheimers and aluminum is quite tenuous.

Tim P.
UVM PMRC

[cncaboose]

Dr. Perkins, Just a genuine thank you from NY for taking the time to respond to our questions and contribute to this forum.

[TapME]

Didn't they try and scare everyone half to death with rumors that cooking food in aluminum pot's caused Alzheimer's?

Just my point, What is a safe level for this aluminum transfer and illness to occur. What are save levels for all the other chemicals before they cause harm. Just want to know what the skinny is.

[DrTimPerkins]

Just my point, What is a safe level for this aluminum transfer and illness to occur. What are save levels for all the other chemicals before they cause harm.

Unfortunately there isn't a "skinny" story. The story is very "fat" (long) indeed. These issues are quite complex due to the large number of variables involved (how much aluminum in the pot, how big the person is, their age/developmental status, their sex, what is their aluminum exposure from other sources...air, water, soil, other exposure factors, how much aluminum in the food of question on average, what is the maximum dose in the food, how is the aluminum complexed in the body, how much is excreted in various ways, how much and where does it accumulate in the body, etc., etc.). All of these (and many more) go into the equation for what the "safe" level is.

In general with these types of materials, you aren't getting a massive dose at one time, but it is a slow accumulation. If the input is far higher than the output, then health problems may occur. Typically the situations when health problems are found are abnormal though, and people will get some high dose exposure from something, and more acute issues will present themselves.

As far as lots of other chemicals go, there just isn't a great deal known and it just isn't a big issue. If they aren't causing problems, there is little impetus to look and to try to answer all these questions in depth, and the questions are so difficult to answer (per above). So for the most part, if it doesn't cause a problem, it isn't greatly investigated. To do that research work for all chemicals would be incredibly expensive....costing hundreds of billions of dollars.

There is the Codex Alimentarus, which covers international standards of food in trade around the world. Generally it focuses on specific food items, standards for those food items, and known issues of spoilage, contamination, and adulteration.

If anything I'd say that maple went a step further than many other industries. During the lead issue, the maple equipment manufacturers formed an industry group, the LMEA (Manufacturers of Maple Sugaring Equipment Association) that came up with voluntary standards for maple construction materials and practices. They were fairly conservative in their approach. If you want more info on that, type "LMEA" and "Maple" (without the quotes) into some search engine (Google, Bing, Yahoo).

Tim P.
UVM PMRC