Hopefully the last word on things leaching from plastic containers, tanks, buckets and cans!

[mcarroll]

I stumbled on this PDF put out by the Chem division of Agilent Technologies (a former division of the H-P from the good old days).

From the article:

The aim of this study was to find a cost-effective means of storing ultrapure water (UPW). The target was to find a low cost material that was free from contaminating metals that might leach into the UPW during storage. Results for selected metals from the analysis of UPW stored over short and long periods are presented. Low-density polyethylene (LDPE) and high-density polyethylene (HDPE) were compared with PTFE perfluoroalkoxypolymer resin (PFA) and PTFE fluorinated ethylene-propy-lene (FEP).

In a nutshell, LDPE is the best.

Another key quote from the results:

The most common elements extracted were Ca, Fe, Mg, Al and Cu.

All of them were only measurable in the parts-per-trillion range, even after multiple years of storage.

The caveats to this info:

The bottles are made from virgin resins with no pigments, additives, or stabilizers.

Good stuff - read the link!

-Matt

 

[JMSKI333]

Thanks for the read! Interesting!

 

[redfishbluefish]

Matt, I first had to chuckle at "last word." Is there such a thing as last word in this hobby?


The second caveat is that all plastics were produced by Nalge.

It would have been nice to know the amount of the tested elements that were in the various plastics to begin with.....known quantities where you could see the rate/amount of leaching.

Nalge specifically makes plasticware for lab use. I'm sure their quality assurance for contaminants in their plastics is closely watched. I would speculate that the plastics we use are from companies using a blend of virgin and recycled plastics. In addition, there is an un-named country that has a very poor track record of producing clean plastics....typically contaminated with heavy metals (lead and cadmium, to mention two). I know this first hand dealing with this country for medical grade plastics. We would get a few batches that were good, and then a contaminated batch. We'd talk, they'd clean it up...and again a few good batches, and then contaminated again. If we weren't diligent in testing these plastics, they'd be contaminated. I am highly suspicious of any consumer plastics coming out of this country...where it isn't regulated....scary.

The bottom line conclusion from this study for us is that if you use Nalge containers for water storage, you will know the amount of leaching elements that end up in your water......negligible (and more so for polyethylene based containers.)

What we wish to conclude from this study....that the Rubbermaid High Density Polyethylene Brute garbage can I have isn't leaching much into the water. In my little mind, this is what I want to think. I'm not sure what companies need to do to get "food grade" status for their plastics, but I'd venture it has to do with leaching/surface contaminants.

 

[mcarroll]

Well..."hopefully" was my leadoff.

What Kind Of Plastic? What was the point?
While they did name the brands (multiple) of plastic, they also named the test gear and reagents they used. I don't think this was intended to change the scope of the paper.

It's worth re-pointing out I think that the point of their test was not to find what brand of plastic leaches the least. (Seems like we may have jumped to the conclusion that this was a test promoting Nalge-brand plastics. Not so.)

The point was to find an inexpensive (i.e. commonly available) plastic that could acceptably hold ultrapure water. HDPE and LDPE - which are the most common in our hobby - came away with great records.

It also seems like it may be worth stating that: even under conditions designed to elicit leaching (high-purity acid in the water; storage for multiple years) and using some of the most sensitive test equipment available, all that leached was in the parts per trillion concentration. Parts-per-trillion is just a very precise, scientific way of saying "nothing". These levels are certainly insignificant in the light of the seawater/chemical soup we ultimately make with this water.

A Brute Is A Brute....Right? What About Phosphates In The Plastic??
FWIW, most 5-gallon buckets are HDPE.

Brute containers are LLDPE.

Also FWIW, there are two lines of Brute can - one that has recycled plastic content and one which does not. I think 99.9% of us have the can that does contain recycled content.

We know Brute's have colorants added (probably dye added to the virgin resin in their case, which is good) and I'd say it's likely they have UV protectants as well since outdoor use is to be expected for many of the Brutes out there.

I can't find any evidence so far that there are phosphates used in any product used for color or additives in this plastic. Interestingly, it seems like anti-oxidents (including some of the ones we know dietarily) are the main additives in polyethylene. Oxidation is apparently one of the only things these plastics are susceptible to.

-Matt

 

[redfishbluefish]

I learned something today.....and that's a good thing.


Matt, I was about ready to tell you that you were wrong, wrong, wrong, in regard to the composition of Brute cans. I had proof on the old 20 gallon I use in the fish room:

However, I did a little search and found that within the last year or so Rubbermaid changed over to LLDPE. Prior to this change-over they used "any number of plastics depending on manufacture date." In my particular case, the manufacture date was a good year for HDPE. I also have another "old" 32g Brute in the basement, but it's filled with water right now. When it's empty I'm curious what I'll find.

 

[redfishbluefish]

I didn't mention, but the Brute above was date stamped 2010. This one below is date stamped 2007.

And so now I scratch my little pea-brain head and question why they jumped around from polymer to polymer? The only thing I could come up with are purchasing issues.....availability and/or price of the polymer.


So now it would appear that purchasing a Brute will be like buying a good bottle of wine, "Ah yes, that was a good year!"

 

[mcarroll]

Interesting. Will give mine a peek when it's empty next time as well.

-Matt

 

[revhtree]

Interesting thread!

 

[mcarroll]

[...]Prior to this change-over they used "any number of plastics depending on manufacture date."[..]

I'd be curious to know for sure, but I doubt that includes anything that isn't polyethylene.

Wonder if they meant "...from any number of sources..."? That would make sense for a product containing recycled content.

-Matt

 

[McolonReefAddict]

Very interesting thread since I've recently been looking for a 15gallon container, I don't know what kind of container to get because i wasnt sure what would be a good material, I was thinking of one labeled "Food Grade", what do you guys think about that? just looking for opinions.
thanks.
Mcolon

 

[Sacohen]

I need to check my 20 gallon Brute when I get home. I just got it about months ago.

 

[redfishbluefish]

Very interesting thread since I've recently been looking for a 15gallon container, I don't know what kind of container to get because i wasnt sure what would be a good material, I was thinking of one labeled "Food Grade", what do you guys think about that? just looking for opinions.
thanks.
Mcolon

Any of the "polyethylene" materials mentions above would be just fine....LLDPE, LDPE or HDPE. I too make up 15 gallons, and the ideal container is the Brute 20 gallon trash can....which you can find at HD. I know gray colored is food grade (as well as some of the other colors they sell.) Fifteen gallons of water comes up to the ridge in the picture below:

 

[kframe]

I'm actually a material supervisor for PolyOne. We extrude all kinds of plastics. From military use to medical use. Any time of color plastic has an additive that is added to it call concentrate. And most of the concentrates used already have an additive "u.v.i". Even your white plastic container have the concentrate additive. Virgin material is almost a clear material when extruded. It's heat to 450 degrees or so and either smoothed out by chrome rolls or matted by a different type of roll. Pretty much all plastic is going to leech, wether you're using LDPE, HMW, HDPE , Or PP. Your best chances of havering less toxic leeching would be in the almost clear plastics that have no additives . We do run some clear plastic but not very much. I would say 90% of the plastic we run has some sort of additive in it. And really the main difference in the different types of virgin material is the density of the material it's self. Some of a higher melt temp and are a stronger plastic. I would think that it doesn't really matter which of the types of plastics used (except for PP) if is has any sort of color to it or if It's suppose/intended to be used outside it's going to have an additive that will leech over time. Sonic you're worried about leeching your best bet would be to find a clear plastic, just make sure it doesn't have the uvi additive in it.

 

[redfishbluefish]

Good stuff kframe.


The white, gray and yellow Brutes are listed as food safe, meeting NSF Standard 2. And for what it's worth, the wine industry also uses Brutes as their primary fermenter, and they don't seem to have a problem.

Bottom line, I've been using Brutes for 7-8 years without issue. My saltwater sits in them for between 1 to 3 or 4 days. I also give them a vinegar cleaning about once a year or so. For the intended use, there is no problem using them. Safe as safe could be.

 

[Sacohen]

My 20 gallon gray Brute trash can says LDPE, but is marked with a 4 not a 2. Is thus still good? I haven't seen any phosphates when I've tested the RO/DI water with my Hannah Checker.

 

[redfishbluefish]

My 20 gallon gray Brute trash can says LDPE, but is marked with a 4 not a 2. Is thus still good? I haven't seen any phosphates when I've tested the RO/DI water with my Hannah Checker.

Any of the polyethylene Brutes (ending in XXPE) are just fine. So LDPE will not be a problem. Or let me state, any Brute will be fine.

 

[Sacohen]

Thanks.

 

[AquaCox]

So I have been searching around for places to buy some of the larger plastic water storage containers (the tall white one i see some people use) for my new build. I don't know of any place local, but they are quite expensive in my opinion online, especially with $100 to $150 freight shipping charge. Something that just popped into my head when reading through this thread about leaching, why not just use an aquarium for water storage! It seems common sense enough but I've never really thought about it I guess because I never see people do it...Some of the the recent posters in this thread talking about a 20 gallon brute, a 20 gallon aquarium is just as cheap and just as common and there is no worry of leaching, same with a 55 gal...Anyone out there already use an aquarium just for water storage???

 

[mcarroll]

Lots of people use aquariums! If you have the space it's a great option. The advantage to other storage options is that the footprint is smaller per gallon.

Depending how big a storage tank you really need, as a compromise I kinda like glass-cages' "10 Tall". Not a bad footprint for the volume. Above ten gallons and you're pretty much into regular-aquairum sized footprints.

AquaFX offers a nice set of plastic tanks as well if you're looking for something bigger.

If you are where your profile says (Indiana), there has to be a farm and feed store near you...they often have big water tanks...and can probably special order something they don't carry. If you're lucky, shipping could be much more reasonable this way.

These guys out of Texas claim to have a warehouse or something in Indiana...might be worth checking them out.

Of course, there's Elkhart Plastics if you're more local to them...but not you'd have to call to ask about sales.

Hope this helps!

-Matt

 

[AquaCox]

Ya there are plenty of farm n feed stores around but usually they only have very large water tanks like the type you would put in the back of a truck, they may possibly be able to order something like what we would be intersted in (a tall container with small footprint) but from what ive seen of prices online for what i would like around 75 gals the tanks are at least $100 or more without shipping, but I could go to an LFS and get a 75 gallon aquarium for $75 AND not have to worry about leaching plastics...just build a stand to hold 2 tanks one above the other and thats prob about the same space as 2 brutes side by side...