Rubbermaid 'Brute' plastic containers

The simple answer, and without getting too chemical-ly: most every version of PE, in its raw form, would be OK for Food Grade use. I used to do all sorts of stuff with PE and a number of other plastics in my medical device days.

The long answer: The difference between LLD and HD versions of Polyethylene is the way in which the polymer chain is created. I always understood it as being a function of the lengths of the polymer chains (LLD being shorter than HD), though just looking around to refresh my memory it suggests that there's actually a difference in the density and length of side-branches attached to the main polymer chain. In either case, both are made up almost completely of one of the simplest polymer components there is, ethylene, which is almost as simple as two methane molecules stuck together. I know there's an O-chemist out there coming out of their skin in the description, but we're trying to be simple. These simple bonds are not very prone to break, so there is little from the polymer than can be dumped into a foodstuff (say, a fermenting must), or can be brought out of the foodstuff and attach to the molecules.

One can run into problems in two ways: First, colorants used in polymer processing are often poisonous, and one has to be very careful as to whether or not these can leach out of containers into foods/liquids, especially where the liquid is both water and alcohol based - both great solvents. This is why containers for food use are usually white, not black, red or blue.

Second, most other polymers (excluding Teflon and fully cured Silicone) are more complicated than PE, resulting in chemicals that can be drawn out of the material if food is stored in them. For example, PVC is made with plasticisers to help the polymer-creating reaction, and these plasticisers remain, at some concentration, in the material after the object is formed - these plasticisers can be drawn out by solvents.

Finally, all of this is a function of time, which is why racking canes and pumps can get away with PVC or Urethane tubing - contact time is way too short to cause a problem.

One final sad bit of trivia - a lot of the animal testing of cosmetics and medical devices one hears about (bunnies wearing eye shadow and lipstick) is an extension of the above-stated chemistry. We weren't allowed by the FDA (who also control the cosmetic industry) to put certain products on the market before we knew that they wouldn't cause unexpected reactions. They've gotten better now in their requirements, but back in the day a lot more bunnies got tested on than really needed to be tested...

Ric wrote:

I know several old-timers who ferment in whatever tubs they get their hands on. One "goombah" used to seal his trash cans with 2-tube epoxies when he neede more primaries, he said it added to the wine's character. For 2-3 weeks primary fermentation, i wouldn't sweat it. If the barrel says food grade, go with it & don't kvetch. JMHO. regards, bobdrob

Nice post. I work with Rubbermaid Commercial Products Division; here is a link to their materials compatibility page which goes in line with your post. They do make products specifically for the food service industry as an aside.

If someone gives me a specific product code they want an answer on I can email them. No guarantees they will definitively answer the question but I can ask.

Joe

Product code 2620 is a 20 gallon round container and, per specs, is made of LLDPE (Linear Low Density Polyethylene). Product code

2632 is a 32 gallon round container and is LLDPE. The lids for both are HDPE, 2619 and 2631.

Is LLDPE food grade for use a primary fermenters in the homebrewing of wine, mead and beer?

In secondary fermentation, oxidation is a material issue. It is generally presumed that HDPE provides oxygen intake barrier while LDPE does not. Is this correct? To what extent does LLDPE provide an oyygen intake barrier?

What is the difference between HDPE and LLDPE for the end-user?

Why are the lids HDPE while the containers are not.

I, and many others, would appreciate a knowledgeable response to these questions.

Thank you very much for any efforts you can make.

Dick

You may want to talk to the manufaturer on this. They will generally answer you questions if you ask the right question. I would assume the lid is HDPE as it may need to be more durable but ????

As far as food grade is concerned there are several issues. First, it could be food grade but not rated for acidic alcoholic food. Both of these factors can act as solvents to leach things out of the container. I would suspect that this in not a problem but, for peace of mind, you may wnat to ask.

Second: It could be fine for single use but not for reuse. If it is low density, some liquid may go into the plastic and not be easily washe out. Then it could become infected during storage and infect your wine the next time you use it. The LD rating would have me concerned about tis. I do not think you will get reliable answers with out contacting the manufacturer but if you do get answers, let us know.

Ray

The original posting that spurred all of this discussion includes a link to the product description which in turn provides a link to a detailed Chemical Resistance Guide.

Now I'm not a chemist nor do I play one on TV, however, it appears to me that the Brute product in question is highly resistant to alcohol and acids, and as previously mentioned, it is food grade (in certain colors). So, are we missing anything here? Is there any reason to believe that this isn't a safe container to use as a primary?

Greg G.

My guess on why the lid is HDPE and the body is LLDPE is manufacturing capabilities. They've likely learned a lot since when I was closely involved in molding and extrusion, but LLDPE was a lot easier to mold (and mold consistenly across a part), and the buckets are obviously molded. HDPE was more easily processed in sheets (or blow molding), so the lid would lend itself to being formed that way.

I can tell you that we tested both these materials for compatibility with polar and non-polar solvents, up to 30 day exposures, without problems like materials leaching out. We didn't test re-use, since we weren't making a reuseable medical device. But I do re-use milk containers without fear after cleaning, and they're PE.

Most raw plastics are transparent or slightly blue translucent if unpigmented during manufacturing. White plastics typically use Titanium Dioxide to give the plastic color (we used about 97%PE/3%TiO2

- no other contents), and Titanium Dioxide is also a typical, acceptable in-food colorant, so even if it leached out it wouldn't be a worry. I've got no direct connection to Rubbermaid, but for them to declare it food grade, they know that their raw materials don't pose a danger to people.

Don't know what to say about stuff leaching *in* to the plastic - that'd be a decent question for Rubbermaid, but I'm not worried about the answer. After all, many of us re-use a much more highly porous, virtually unclean-able container on all our wine batches - an oak barrel. If we can keep those clean, we can live with buckets, I imagine.

Rob, Just to confirm what's been said already, I went outside and checked my gray 32 gal Brute. Both the lid and can are rated by the National Sanitation Foundation as safe for food contact, which falls under NSF standard 2, which deals with food handling eqpt. White, gray and yellow colors are approved for food, but all colors are approved for trash (NSF std 21, as if it mattered what you put the trash in!)

I have used the gray cans for primaries and bottling tanks for years without problems. No staining of the cans, but the closed up fermenter smelled wonderfully fruity when I opened it up just now. Apparently a little something does diffuse into the LDPE cans.

Mike Cokesbury, NJ, USA

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Rob, Just to confirm what's already been said, I went outside to the barn and checked my gray 32 gal Brute.

Both the lid & can are rated as safe for food contact by the National Sanitation Foundation, under their NSF std 2, which covers food handling eqpt.

White, gray and yellow are OK'd for food, while all colors are safe for use as trash cans. (Don't laugh! NSF std 21 says it's safe to put garbage in colorful cans.)

I've used gray Brutes for years as primaries and bottling tanks with no problems. No stains, even from inky reds, but a wonderfully fruity aroma greeted me just now when I took the lid off my stored primary. So I guess a little something does diffuse into the LDPE cans.

I call both Rubbermaid and US Plastics and spoke when two exceptionally knowledgeable people. My conclusion is that the Yellow (my choice), White, and grey 5620 and 5632 Rubbermaid Brute Containers with lids are a great buy for primaries. US Plastics does manufacture and sell HDPE containers of 20 gallon plus, but they start at over $80 each.

Dick

I'm sure that if they say these three colors are food-safe, then they've tested them completely for food safety, including extractions into whatever food is contained in them. I didn't mean to exclude grey and yellow, I just don't know what the typical colorants are that are included in the plastic to give those shades, so I didn't want to speak about them. Just trying to hide a little of my ignorance :-). Having said that, we did make devices out of gray and yellow polypropylene which were tested and passed all biochemical tests - I'd figure that those colorants could be included in PE and pass as well.

Either that or it's not as clean as you think! I always store my primaries upside-down and unlidded.

One more story, just in case y'all aren't completely bored yet. And in telling this, I am in no way condoning using any container not labeled food grade for containing a foodstuff such as wine, mead, etc. I have had a serious discussion (in years past) with a plastic-company representative. Food grade plastic costs more because of the testing needed to prove that it's safe, but frequently there is no difference in composition from that and the identical-looking container next to it from the same company not labeled food-grade. Unless it's custom-compounded to the end-user's specifications, the original plastic-maker is likely only to have one formula for a particular plastic. In other words, you'll pay more for uncolored food-grade PE from Joe's Chemistry Company than uncolored non-food-grade PE from Joe's Chemistry Company, even though the material is identical, and in fact were run at the same time. You're paying for the testing that they perform to prove it's food grade, not necessarily a fancier material. You want that proof, for you and the consumers of what you're making, so again, I'm not condoning use of non-food-grade materials. But that's how the processors work.

Rob

Both points heard & understood. However, the primary had been rigorously cleaned with percarbonate (Oxyclean) and a stiff brush. As for the preference for open, airy storage, my barn is plagued by cave crickets. While fearsome looking but harmless, they leave little fecal spots where they roost. That's something I'd like to avoid, I think. Mice, too.

BTW, does anybody else have problems with cave crickets in their wine cellar?

I pretty much suspected this.

Did either of them speak to Ray's point about re-use? That seems to be the only open question here.

Erroll

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Often it is the case they are identical, but having been in the plastics molding business, I know that the ones not labeled food grade sometimes have reground production scrap in them, and the purity of the regrind cannot be guaranteed. The ones marked food grade in my experience were made only with virgin resin with traceable lot history.

Gene

As a personal decision, I am comfortable re-using my plastic NSF grade containers for fermentation.

I do know that the various types of polyethylene plastic do absorb material from the fermenting must... but as long as i am using the container only for the same thing, what is already absorbed into the plastic is the same thing i'm fermenting the second time around.

As a previous poster said, sanitation with percarbonate (oxyclean) is sufficient, and his comparison to oak barrels absorbing stuff from the wine is same as my understanding.

I have one well-stained white plastic NSF approved food grade fermentor that i use for extended maceration of some of my red wines. The stain is absorbed, not just on the surface.

As a chemist, I understand the mechanism of the staining. The aldehydes, esters and alcohols (and traces of stronger organic solvents made as byproducts of the fermentation) in the fermenting must open up near surface pores in the plastic by a mechanism known as 'swelling', into which the wine material diffuses. HDPE is the most resistant to this. Polypropylene and LLDPE are more susceptible, being lower density materials to start with.

Eventually the surface of the plastic will start to break down due to the repeated swelling/shrinking cycles. This is observed as a less glossy surface, akin to comparing flat paint to semigloss paint. At that point, I choose to use the container for trash only.

Gene

Yep. All true, and I've seen it myself. Which is why I was in no way encouraging use of non-food-grade materials.