These scans were done with the purpose of enabling you to make easy, safe choices when buying items for your home.

Brand

Pyrex

Does this have lead?

Yes

Where can I buy this?

Thrift Store

Item Type

Glass casserole dish

Year Sold

1970's

Test Results

Positive for lead with Fluoro-Spec

Is this safe to use? (Full explanation)

Probably not

About XRF Testing?

I used a Niton XL 5 Plus made by Thermo-Fisher to scan this item. Portable XRF isn't perfect but it does give a very good indication of generally how much lead things have in them, the pictured scan is within average of the scans taken on this object.

I keep the device set to 1.5 sigma, which means that when it collects information about the sample, this means that the about 86% X-Rays that come from the sample are within 1 standard deviation of the number under the PPM column plus or minus the numbers under the margin of error column. While not perfectly accurate in my opinion this is plenty accurate for getting a good indication of how much or little lead there is.

Let’s use a thermometer as an analogy

Lets say I have a thermometer that reads the temperature as 100°F.

Margin of Error:

The thermometer comes with a margin of error of ± 5 degrees. This is like saying your thermometer is accurate but not perfect—it can be off by a bit.

What 1.5 Sigma Means:

• 1.5 sigma in this context means that there’s an 86.64% chance that the actual temperature is within 5 degrees of what the thermometer reads.

• So, if your thermometer reads 100°F, you can be 86.64% confident that the real temperature is between 95°F and 105°F.

Breaking It Down:

• Imagine your thermometer is a bit fuzzy and can fluctuate a little.

• When it shows 100°F, it’s saying, “I’m pretty sure the temperature is close to 100°F, but it might be off by up to 5 degrees.”

• This 5 degrees is the margin of error.

Confidence Interval:

• This margin of error creates a confidence interval from 95°F to 105°F.

• You can be 86.64% confident that the true temperature lies within this range.

Summary:

• Your thermometer reading is 100°F.

• The margin of error at 1.5 sigma ± 5 degrees.

• You can be 86.64% confident that the actual temperature is between 98.5°F and 101.5°F.

So while not as accurate as other methods which destroy the sample, dissolve it and test, its wayyyyy faster and accurate enough for practical purposes.

XRF scanning is not a leach test and does not indicate how much lead comes off an item when you use it, but a general rule of thumb is that the higher the lead levels in an object the more likely lead is to leach into your food. The amount of lead that comes off will vary based on what kind of material it is and how its used.

I have a full write up on this on this page.

About Fluoro-Spec (FS) Testing

Testing with FS uses some of the same principals as XRF, however it requires the lead to be

• On the surface

• Chemically converted into a crystal by the FS testing liquid

• Dry

This means that the form of lead and its presentation needs to be on the surface and easily broken down, this means anything that glows with the FS test kit will release a lot of lead when you touch it.

FS does not detect buried or chemically inactive forms of lead, however under many circumstances this may not give you significant exposure to lead since its locked up.

Fluoro-Spec is like a seat belt, It helps significantly in most cases but there is always the risk of truck falling off the overpass, with that being said its the most sensitive lead testing kit, available at the lowest cost ever and there are no false positives for elements other than lead.