All About Jars

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Do Weck Jars Contain Lead?

date 2018-09-07T21:04:00.000Z

Do Weck Jars Contain Lead?

I’d had this question for quite some time and have researched the idea on more than one occasion with no certain answer. The internet is full of speculation regarding Weck jars and lead.

There are the well-known accounts of Tamara Rubin of MisLEAD  declaring her special lead detector (XRF Testing) reads positive for lead in Weck jars, (video here) and mentioned in an article here.

Weck and Lead

Then there were accounts of Weck admitting to using lead in the production of their product (see this video) and the comments halfway down the page of this article, but assuring that there was no possible way it could migrate out of the glass and contaminate your food.

For convenience, here is the commentator's note referenced above:

I e-mailed Weck Jars, and here is their response:
Yes WECK’s products are tested every year by the Drug and Food Administration in Germany. Not only the end products but all of the components. There is no chance of lead or any other chemicals used in the manufacturing of WECK jars to migrate into the food or liquid that would be put into WECK jars. This is the statement WECK has sent us:
Total elimination of lead in the glass is not possible. The small percentage detected is minimal and migration into the food impossible.
The German food and drug administration responsible for Food safety is testing the composition of the glass mixture, as well as the rubber ring annually for food storage safety
I have also attached the testing results that were done in Germany.*

Weck’s confidence was backed by the strict European standards (Made in Germany) and frequent testing of both their jars and rubber rings (seals/gaskets).

However, I haven’t seen the results of these studies published anywhere.

More time researching led me to this statement on Life Without Plastic:

Note: If you are concerned about the possibility of lead in Weck glass products please note that we have conducted leach testing with a U.S. Consumer Product Safety Information Act-accredited laboratory and no lead was detected.

This statement certainly made me feel better because I own several Weck Jars of varying sizes and shapes. Yet, the results weren’t published publicly, to my knowledge, and no detailed information about the testing was provided.

Simply put...

I had to test it firsthand to be as sure as I could be that my family wasn’t inadvertently ingesting lead on account of these lovely, functional and marketedly ‘clean’ (plastic-free, toxin-free) jars.

So I bought a set of lead test strips that are designed to do just that: test for leachable lead.

In fact, this Lead Test Kit tests for leachable lead using one of the two ways that concern home canners: high-acid foods and high heat. The FDA claims that improperly glazed pottery, for example, can leach lead into “food and drink that is prepared, stored, or served in the dishes.” This lead test kit requires that you leave distilled white vinegar – a high-acid substance – in the vessel for at least 4 hours prior to testing for leachable lead.

The Testing

We poured distilled white vinegar into several vessels and left it overnight.

These included:

  • Ball mason jars, both blue tinted and clear glass
  • Kerr mason jar
  • Weck jars
  • Le Parfait terrine
  • Le Creuset small ramekin

Be glad you weren’t the one doing the experiment because the rotten egg smell was extremely pungent and lingered for hours. I can see why they recommend testing in a well-ventilated area! Thanks, Hubby, for being the scientist on this one!

The Results

None of the above vessels showed even a trace of leachable lead – not the Weck jars, the blue Ball jar, Le Parfait, Le Creuset or Kerr brand. None. Nothing. Nada.

It was an astoundingly boring experiment as far as chemistry is concerned. But a very happy ending to finally  stop worrying about Weck jars leaching lead!

In Summary

There are 3 facts which help to prove that Weck Jars don’t leach lead:

1. Science.  Formed glass is inherently a nonporous substance. Even if Weck adds lead to their glass, or even if trace amounts of lead are found in the Earth’s natural materials, what’s in there when the glass is formed at amazingly high temperatures is most likely going to stay in there, due to the logistics of porosity.

This concept, however, may be challenged in the area of glazes on earthernware, pottery and ceramics. Read this article for more information.

2. Anecdotes.  Both Weck Jars/Glaushaus and Life Without Plastic assert that testing has been done, and it is not possible for Weck jars to contaminate our food via leachable lead.    

3. Additional testing. The testing of my specific jars with a leachable lead test kit using a high-acidity substance (white vinegar) confirmed that lead does not leach from the glass to its contents.

Disclosure: This article may contain affiliate or sponsored links to products that I recommend. By following these affiliate links and/or making purchases, I may receive compensation at no extra cost to you. Thank you for supporting the work of this website!