When tested with an XRF instrument the small burnt orange Franciscan potteries dish (made in California) pictured here had the following readings on the FOOD SURFACE of the dish:
- Lead (Pb): 228,400 +/- 8,600 ppm
- Barium (Ba): 2,765 +/- 437 ppm
- Chromium (Cr): 398 +/- 212 ppm
- Tin (Sn): 62,800 +/- 2,400 ppm
- Zinc (Zn): 535 +/- 55 ppm
- Copper (Cu): 296 +/- 123 ppm
- Iron (Fe): 593 +/- 138 ppm
- Vanadium (V): 1,546 +/- 629 ppm
This dish was tested for a full three minutes (180 seconds) to ensure the most accurate possible reading.
I will update this post with more information shortly, but in the meantime, please read some of the other posts I have written about vintage dishware to better understand the test results reported on this website.
As always, thank you for reading and for sharing my posts.
Please let me know if you have any questions.
Tamara Rubin
#LeadSafeMama
Candy Eve says
I have mustard yellow and gray. I believe the pattern is called “Metropolitan”. Were my mom’s. She and I never used them, as far back as I remember. Are those colors most likely the same lead amounts? I assume they are.
What do we do with this stuff?
Tamara says
Very likely highly leaded – Franciscan is not a safe brand for use for food (as a rule.) Here’s my article on “what to do with them” – https://tamararubin.com/2019/12/what-should-i-do-with-my-lead-contaminated-dishes-to-toss-or-not-to-toss/