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earthsaver77
03-19-2013, 01:35 PM
I hope that this information comes in useful.

Plastic containers and tubing are great, but nobody wants the plastic smell or taste in their products. It’s easy to get rid of them from newly manufactured products.

Soft plastics, unlike rigid plastics (like polycarbonate, Lexan, Nalgene, etc) all outgas compounds like aromatic hydrocarbons, aldehydes, and ketones. All soft plastics contain BPA, which is a chemical that mimics estrogen and is an endocrine disrupter. Plastics labeled as “BPA Free” are all rigid plastics, and will shatter upon hard impact. What we use for tubing and food-safe containers still contains BPA. Keep that in mind. BPA is a hot topic right now, but it’s not necessarily the only hazardous chemical in plastics.

Your worst enemy is heat. Plastic products are quite stable in low temperatures, but the warmer it gets, the more chemicals it will release. Keep all plastic containers cool and in the shade year round, and get tubing that is light colored and UV protected so that they stay cooler.

Outgassed chemicals from new soft plastics can be quite strong. Think of that new car smell. That smell comes from plastics. If you have ever tried to clean the inside of your car or truck’s windshield, the film that seems almost impossible to remove from the glass is actually the outgassed vapors from your plastic dashboard. Now, imagine that same film on the inside of your plastic containers and tubing. It won’t go away on its own, and it will continue to appear over the lifetime of the plastic product.

At a bare minimum, rinsing soft plastics with plain water is ok, but the oxidation potential of plain water is insufficient and can take weeks to have any effect on getting rid of chemical surface film without a surfactant or stripping agent such as soap or alcohol.

Soap has its purpose, but it can leave a residue that doesn’t come off some soft plastics easily without high pressure or abrasive action. Soap residue can accumulate on the interior walls of tubing, and flushing a dozen cotton balls through it under pressure is effective, but just very time consuming. Large containers can be pressure washed without too much trouble, but here are some other methods if you want to avoid using soap to get rid of the chemicals that leave a plastic taste or smell.

Top on my list is ethyl alcohol, but it’s expensive, so methyl alcohol in the form of rubbing alcohol works great. With the alcohol method, fill any plastic tubing, fittings, or containers with diluted rubbing alcohol (isopropanol). The alcohol will dissolve chemicals that don't dissolve well in water. The longer your alcohol solution is in contact with the plastic surface, the better it will remove the aromatics. An hour is the bare minimum, and there’s no real benefit beyond a week.

Next best is an overnight to 3 day flush of hydrogen peroxide followed by a few hours of soaking with a baking soda solution.

For tubing, it’s best to circulate the fluids using a pump. For large containers, just fill them and let them sit for a day or two.

Either method will require a carbon rinse, which absorbs any residual ketones and neutralizes the other products used to “strip” the plastic of residual chemicals from the manufacturing process.

The final treatment is the most important step. You can always use just plain water, but including carbon works wonders.
I prefer rinsing with a solution containing solid carbon. I flush tubing or fill containers with water containing pre-washed hardwood charcoal or the rock-like activated carbon chips found in aquarium supply stores. A little goes a long way. One pound of charcoal is sufficient for 100 gallons of water.

Pre-washed charcoal is the key. You don’t want charcoal powder getting into the cleaning water, because it’s chemical nature will be to stick to plastic, and it’s very hard to remove. Rinse charcoal with agitation and keep changing the water until your water remains clear before putting it into a container to soak or into the water flushed through tubing. Charcoal dust is non-toxic and could even residually reduce the load of chemicals released from plastic into your liquids over time, but it really looks terrible.

When in use, minimize heat, and minimize the amount of time fluids remain in contact with your plastic tubing and containers.
When not in use, just keep plastic equipment cool and sheltered, and when it’s time to put it all back into production, give yourself plenty of time to give these items a good soaking and rinse with plenty of fresh water.

DrTimPerkins
03-19-2013, 02:39 PM
With apologies upfront, I'm going to have to disagree with much of what you've written. Unfortunately it is not as simple as all "soft" plastics contain BPA and not all "hard" plastics are BPA free. Both rigid and semi-rigid polyethylene (in maple tubing) as well as nylon (most opaque spouts and fittings) contain no BPA and, as long as food-grade virgin polymer is used in the process, these are all food-grade according to the FDA. Polycarbonate (a very rigid plastic) on the other hand, used in many (not all) of the clear maple spouts, does contain BPA. Many highly clear hard plastics (like baby bottles and sports water bottles) formerly contained BPA. Many of those products have been reformulated though, so it's impossible to tell by looking at them alone (unless you look at the code on the bottom -- 1,2,3,4,5,6 generally have no BPA, 7 "may" contain BPA, 3 will very rarely have some). PVC, which can be either hard or soft, typically contains some BPA, which is used as a polymerization inhibitor (so more in soft PVC, less or none in hard PVC).

Methyl alcohol (wood-alcohol) is not the same as isopropyl alcohol (rubbing alcohol). Neither are food-grade (but ethanol is ;) ). UV inhibitors in tubing have no effect on temperature of the tubing (you're barking up the wrong end of the light spectrum).

Activated carbon sold in aquarium stores is most likely NOT food-grade. If an inspector saw it in your sugarhouse, you might be in for a lot of questions for a variety of reasons (which I won't go into). The powdered form is an inhalation hazard, and it can be a PITA to rinse out of plastics, especially if there is any static.

Bottom line is that modern maple tubing is food-grade, and most people don't flush their tubing, and the plastic odor will be largely dissipated after the first run. It may reappear at the start of the next year a little, but after that, it's gone. I certainly would NOT take a food-grade material (like tubing) and soak it or flush it out with non-food-grade materials (non-food grade alcohols and non-food grade activated charcoal). Rinse with water if you like. Better yet, let the first bit of sap run on the ground if you are very concerned about it.

Burnt sap
03-19-2013, 02:59 PM
I agree with you sir. Where does a mix of bleach and water stand in this arena? Since we use it to clean food prep areas, hospitals and the list goes on and on.

DrTimPerkins
03-19-2013, 03:02 PM
Where does a mix of bleach and water stand in this arena?

It is acceptable. Copious rinsing is advised after use. Squirrels love it.

DonMcJr
03-19-2013, 03:24 PM
With all that said...What is the best way to clean out my tubing for storage at the end of the season? I only have 15 taps and I have a hose fitting that I hook onto the hose, pull the taps and flush hot water through it all from the container end to the taps no longer in trees. I was going to pour some bleach into the hose and then hook up the hot water and flush it all for 10 miutes or so.

Will the bleach harm anything by my maple trees? Would just flushing with plan hot water for 10 minutes be better?

After the flush I was going to tape off the ends and pull down the tubing and store in a closed container til next year...

DrTimPerkins
03-19-2013, 03:34 PM
What is the best way to clean out my tubing for storage at the end of the season?
Will the bleach harm anything by my maple trees? Would just flushing with plan hot water for 10 minutes be better?

Very simply, we don't know if cleaning (with anything) does much beyond making you feel good. With that small a system, flushing it with hot water is fine, or with bleach followed by a good rinse. Don't overdo the bleach though. Chlorine is not good for plants, and the squirrels like the taste. Most larger producers do not take tubing down....it stays in place year-round.

Burnt sap
03-20-2013, 06:29 AM
Thanks for all the info. Now as an Organic producer of maple syrup is bleach and water still accepted? In the past we just used water and pumped the lines including the droplines and taps.

Asthepotthickens
03-20-2013, 06:36 AM
So am I correct in taking out my spouts with plastic line, running hot water through them and then storing them in a 45 gallon plastic drum for the season? I can not get all of the water ( condensation ) out of the tubbing. The few main lines I have I leave up blocking both ends.
Thanks doc

DrTimPerkins
03-20-2013, 08:13 AM
... as an Organic producer of maple syrup is bleach and water still accepted?

Since there are no national organic standards for maple, it would depend upon your certifying agency. Check their rules.

DrTimPerkins
03-20-2013, 08:15 AM
So am I correct in taking out my spouts with plastic line, running hot water through them and then storing them in a 45 gallon plastic drum for the season?

We do not know the best way to clean plastic tubing systems. That way sounds as good as any other.

abbott
03-20-2013, 01:41 PM
Now as an Organic producer of maple syrup is bleach and water still accepted? In the past we just used water and pumped the lines including the droplines and taps.

Don't quote me on this, but I believe in Maine, MOFGA allows a bleach rinse of the tubing. I am MOFGA certified, but I just use water to rinse, so I am not positive on that.

I've been thinking a re-rinse in late fall would be helpful. Go through and repair squirrel (and coyote in my case) damage, then rinse out the bacteria that has formed over the summer. Might not have to dump as much sap in the spring to get the crud out of the lines. That might be the time to do the bleach, when the squirrels are less active and have less lime to do damage.

The Sweet Spot
03-20-2013, 09:00 PM
I ran clean water through my lines plugging from the bottom up. Shut the water off and pulled the plugs. When the water drained I repluged the taps. When we tapped this year I had 3 chewed off taps and 3 broken t's.

The Sweet Spot
03-20-2013, 09:04 PM
I ran the sap on the ground as we tapped the line. There is 67 taps on one 5/16 line (my gravety experement) when we were finished tapping I ran sap into a qt. jar and had no particals at all. I put a filter on the end of the line and found nothing hardly at all, mostly wood shavings.

Burnt sap
03-21-2013, 10:42 AM
Thanks Doc, Good sugaring to you.

CampHamp
03-21-2013, 11:26 AM
Dr Tim, I read your article on tube cleaning in the Oct 2012 "Maple Syrup Digest" and it made me wonder if it makes any sense to clean my tubing at all. Is this article something that you can share here or is it copyrighted material?

DrTimPerkins
03-21-2013, 11:40 AM
Dr Tim, I read your article on tube cleaning in the Oct 2012 "Maple Syrup Digest" and it made me wonder if it makes any sense to clean my tubing at all. Is this article something that you can share...

All our Maple Digest articles are posted on our website at http://www.uvm.edu/~pmrc/ Look at the right under "Recent Publications."

RIFoster
03-17-2015, 12:29 PM
...
Bottom line is that modern maple tubing is food-grade, and most people don't flush their tubing, and the plastic odor will be largely dissipated after the first run. It may reappear at the start of the next year a little, but after that, it's gone. I certainly would NOT take a food-grade material (like tubing) and soak it or flush it out with non-food-grade materials (non-food grade alcohols and non-food grade activated charcoal). Rinse with water if you like. Better yet, let the first bit of sap run on the ground if you are very concerned about it.

So the first year you're stuck with the plastic taste? I ask because I have 14 taps on a set of lines, and so far I've gotten about 2.5 gallons, all of which I had to dump.

DrTimPerkins
03-17-2015, 02:04 PM
So the first year you're stuck with the plastic taste? I ask because I have 14 taps on a set of lines, and so far I've gotten about 2.5 gallons, all of which I had to dump.

No, the plastic odor and taste is in the sap, but does not make it through to the syrup.

RIFoster
03-17-2015, 02:07 PM
No, the plastic odor and taste is in the sap, but does not make it through to the syrup.

Does the heat simply break it down so that it's no longer aromatic, or does it actually boil away into the air? the last thing I want is concentrated (but tasteless) esters in there.

northwoods_forestry
03-17-2015, 02:38 PM
I sat in on Dr. Perkins presentation on cleaning tubing in 2014 and found it to be very informative. My take home was that there was no significant difference in bacterial levels in tubing cleaned with chlorine bleach, peroxide, etc, or plain water. Further, there was no difference between tubing cleaned with any agents vs. uncleaned tubing. I am still amazed that anyone uses any type of chemical to clean tubing when there is no evidence that it does anything.

That said, I still go through the physically demanding process of running high pressure air & water through the lines after every season. I guess old habits are hard to break...

Atgreene
03-17-2015, 06:46 PM
We flush ours each spring before tapping with clean water. It makes us feel good, and the broken fittings and squirrel holes are easier to find. Some years we haven't washed, but its nice to see clean sap on that first run rather than crud from the line. Thanks for the info Dr.

DrTimPerkins
03-17-2015, 07:09 PM
Does the heat simply break it down so that it's no longer aromatic, or does it actually boil away into the air?

To my recollection (it was some time ago that we did this work), we compared plastic compounds in sap and syrup made with and without plastic materials. In general, most everything we consume has some amount of residues from food manufacturing or storage containers, and syrup is no different, however the material and levels were not concerning. Whether you collect with plastic tubing (or bags or buckets) or with metal buckets, you can detect something in the product.

Starting Small
03-17-2015, 07:58 PM
No, the plastic odor and taste is in the sap, but does not make it through to the syrup.

I posted this on another thread but when I saw this I am second guessing myself. I used a garden hose (I know, not a smart move) to pump 200 gallons of sap this weekend because I needed the extra length because I could not get my truck down to where the tank was because of the snow. Now I have sweet in the pans that tastes bad like plastic. I was going to dump it assuming it picked up the taste from the garden hose. Dr. Tim, are you saying that I should finish it and the syrup would not have a plastic taste? It seems to have more of this taste as it concentrates. Just want to make sure before I dump it. Thanks,
-Dave

DrTimPerkins
03-18-2015, 07:24 AM
I used a garden hose (I know, not a smart move) to pump 200 gallons of sap this weekend because I needed the extra length because I could not get my truck down to where the tank was because of the snow. Now I have sweet in the pans that tastes bad like plastic.

Dump it. This is a different thing altogether. Garden hose contains regrind material and extra plasticizers and often has elevated levels of heavy metals and is NOT food grade. Maple tubing is made from virgin (meaning never before used) polyethylene, and is food grade. Tough lesson, but you won't do it again.

Big Stoney
03-18-2015, 07:19 PM
What should you use for line to pump out your storage tanks?

DrTimPerkins
03-18-2015, 07:21 PM
What should you use for line to pump out your storage tanks?

You can use maple mainline, potable water pipe, milk-hose, or any other water-potable or food-grade hose. They also do make a drinking water type "garden hose"....typically it is white and labeled for use with drinking water.

TrentonMaple
03-20-2015, 12:00 PM
You can get potable water "garden hose" at most big-box home stores. I got mine at lowes. It's white and definitely different material than garden hose. Doens't have that awful hose smell/taste either. People use it for RVs to move potable water.