FBC Health verdict from 3/4 of a material science engineer

[Collin]

I'm a longtime lurker of the forum but am doing my first long hike (Long Trail, VT) in the summer and became interested in Freezer Bag Cooking (FBC). Since some folks were curious if plastics leech into the food- here are some items I collected:

The short- it should be fine. Don't make a habit of cooking all your meals in it for the rest of your life, but that's about it.

Ziplocks (and most other bags) are made of LDPE or HDPE (mostly LDPE). That is low density polyethylene. Here is the Material Safety Data Sheet (MSDS) on them both:
http://www.pattersonvet.com/msds/078408296

Specifically, "Ingestion: Not expected to be an ingestion problem; no first aid procedures are required"




This is why we use it for food and in microwaves. There are a number of other MSDS for LDPE that are more specific to different shapes and whatnot, but ingestion regarding them all seem to only be concerned with gastric blocking (like if you swallowed the whole bag).

I noticed online that someone got a written response from Ziplock on this and they said not to do it since the bags break down starting at 192 degrees F. That seems about right (my textbook says 220 F, but I imagine Ziplock is more concerned about their seams deteriorating first).

So there is my opinion. Take it with a grain of salt because this is the internet. heh.

[Connie]

I read the Ziplock brand website, very thoroughly, one time during the controversy.

Ziplock was very clear their food safe bags are not boil-in-a-bag certified.

However, Ziplock reported that poured hot water was acceptable, that poured boiling water isn't boiling hot water when it is poured.

It should be noted that their stronger freezer bags were recommended, not the ordinary Ziplock bags.


FWIW, Industrial Technology Bachelor of Scrience program in materials science, Western Washington State College, Bellingham, WA.

[fastfoxengineering]

Anybody know the difference between Ziplock Freezer Bags vs Ziplock Screw Top Containers which some use for fbc type style cooking?

It just never felt right eating out of a ziplock bag to me.

[Connie]

I don't know.

I don't use soft or hard plastic containers.

I admit I don't bother to lookup the facts, because there is so little labeling required.

I understand Europe has a higher standard for "washing" during the process of making soft and hard plastic water containers and soft or hard plastic food containers.

I don't even know that for certain, only that Europe has a requirement for "washing" cadmium we don't have.

I stopped using soft and hard plastic containers and I never looked back.

[Miner]

The idea of a boil-in-a-bag is very different then Feezer Bag Cooking (FBC). Boil in a bag is dropping a bag into water and boiling that water for an extended period of time. Uncle Ben makes some boil in the bag rice packets that are meant to be used this way. Freezer bag cooking is usually pouring hot water into a bag with food where the temperature is slowly dropping with time until the meal is cooked (if you can really call it cooking rather then rehydrating). Even with the use of a cozy, the temperature in the bag is dropping.

Most people doing FBC aren't actually using boiling water in the bags. Few people bother to actually bring their water to a full boil and accept the presence of numerous small bubbles forming as enough. From my own measurements, I seem to use water in the 180's F.

[Collin]

I read the Ziplock brand website, very thoroughly, one time during the controversy.

Ziplock was very clear their food safe bags are not boil-in-a-bag certified.

However, Ziplock reported that poured hot water was acceptable, that poured boiling water isn't boiling hot water when it is poured.

It should be noted that their stronger freezer bags were recommended, not the ordinary Ziplock bags.


FWIW, Industrial Technology Bachelor of Scrience program in materials science, Western Washington State College, Bellingham, WA.

Cool Connie. My program is mechanical engineering, but I am focusing in microstructures and mat sci.

I just wanted to provide the information for folks that I would use. Maybe I am approaching this differently from most folks though. I admit that somewhere between 190F and 220F the LDPE will begin to soften/break down a little, but I have no issue with that in my food because of the toxicity report. Especially if this is not something you are doing exclusively to eat.

[Connie]

FBC is "freezer bag cooking" not the less sturdy ziplock bags.

I don't actually boil water.

65 C/149 F is "pasturization" temperature killing micro-organisms in milk and in water.

I get a few small bubbles, the water "smokes" or one or two bigger bubbles of roiling hot water and I pour the hot water in the dehydrated food or freeze-dried food bag package. Ziplock freezer bags look better to me than the package.

I am only rehydrating the food. The food is already cooked before I add the hot water. The insulated cozy helps retain heat 15-20 minutes maximum, many packaged dinners are ready in 10 minutes.

I loved mechanical engineering, at university.

[One Half]

what about the vacuum freezer bags like you use in a home vacuum bag machine? Safer? Less Safe? Same?

[Connie]

I use vacuum pak bags. These bags are microwave food safe bags.

They are freezer bags.

The same standard applies.

The boil-in-a-bag is a different standard.


Edit: I found 1 pint and 1-quart vacuum pak size bags in the store.

I immediately thought, these are backpacking serving size. I will use my Seal-a-Meal and my Snippit!

No more single row ziplock opening up.

I purchase double row ziplock freezer bags, when I see them in the grocery store.

Meanwhile, I will repackage the prepared meals in the vacuum pak serving size.


Snippit http://www.tangiblesltd.com/snippit.htm

[lonehiker]

I use the very flimsy bread/storage bags (for FBC) and have been for probably 15 years. I am not dead yet. Changing topics slightly, I have never had one leak either.