Supporting Details & Studies on the Appropriateness of #XRFTesting
This post was written as supporting documentation to a post about the Green Sprouts sippy cup focusing on the appropriateness and efficacy of XRF testing as a methodology for consumer goods testing. Thanks for reading!
If you take the time to read this and follow the links, I applaud your efforts to better understand the concerns and specifics of this situation and the testing methodologies available!
I am posting this page to support a blog post I will publish shortly about the efficacy of XRF testing used for testing (for example) the painted film on the Green Sprouts Sippy cup. I will link the post here when it is complete. In the meantime here are several relevant points.
“What if the component part is covered or sealed?
Yes. A component part of a children’s product is deemed to be not accessible to a child if the part is not physically exposed by reason of a sealed covering or casing, and it does not become physically exposed through reasonably foreseeable use and abuse of the product. Reasonable foreseeable “use and abuse” includes: swallowing, mouthing, breaking, or other children’s activities, as well as the aging of the product, as determined by the Commission. In addition to passing all applicable use and abuse testing, children’s products which are enclosed, encased, or covered by fabric must measure 5 centimeters or greater in all dimensions to be considered inaccessible.”
Please note the Green Sprouts cup is not “sealed”; based on reports I have received from parents across the country it is easily (and often) disassembled by children (children under the age of 4) and often treated like a puzzle. Additionally, parents often use the interior glass bottle as a drinking vessel for the child (without any of the exterior plastic sheath). So it fails the above test.
also
“(D) Alternate reduction of limit
If the Commission determines under subparagraph (C) that the 100 parts per million limit is not technologically feasible for a product or product category, the Commission shall, by regulation, establish an amount that is the lowest amount of lead, lower than 300 parts per million, the Commission determines to be technologically feasible to achieve for that product or product category. The amount of lead established by the Commission under the preceding sentence shall be substituted for the 300 parts per million limit under subparagraph (B) beginning on the date that is 3 years after August 14, 2008.”
The testing I have done on the newly produced glass Avent baby bottles show that it is obviously technologically feasible for a product like this (a baby bottle for children with painted markings on glass) to be lead-free.
and
“(f) More stringent lead paint ban
(1) In general
Effective on the date that is 1 year after August 14, 2008, the Commission shall modify section 1303.1 of its regulations (16 C.F.R. 1301.1) by substituting “0.009 percent” for “0.06 percent” in subsection (a) of that section.”
This lower limit is equal to 90 parts per million – which is the current (2017) limit restriction on lead in coatings for items intended for children.
and
“(3) Methods for screening lead in small painted areas
In order to provide for effective and efficient enforcement of the limit set forth in section 1303.1 of title 16, Code of Federal Regulations, the Commission may rely on x-ray fluorescence technology or other alternative methods for measuring lead in paint or other surface coatings on products subject to such section where the total weight of such paint or surface coating is no greater than 10 milligrams or where such paint or surface coating covers no more than 1 square centimeter of the surface area of such products. Such alternative methods for measurement shall not permit more than 2 micrograms of lead in a total weight of 10 milligrams or less of paint or other surface coating or in a surface area of 1 square centimeter or less.”
The method used is the approved x-ray fluorescence technology not “an alternative method”, so the discussion of the efficacy of alternative methods may not actually apply here (it depends on how you parse out that sentence!)
and:
“(A) Study
Not later than 1 year after August 14, 2008, the Commission shall complete a study to evaluate the effectiveness, precision, and reliability of x-ray fluorescence technology and other alternative methods for measuring lead in paint or other surface coatings when used on a children’s product or furniture article in order to determine compliance with part 1303 of title 16, Code of Federal Regulations, as modified pursuant to this subsection.”
To my knowledge, no such study was performed determining that x-ray fluorescence technology was in any way not reliable as a screening tool for this type of testing.
NOTE: in fact,the XRF has been determined to be an effective field screening tool (see below) AND the only actual relevant considerations that are part of the discussion is that if another testing methodology were used to test a thin painted film on glass (for example scraping the film off of the glass and testing it independently) the outcome (in the case of the Green Sprouts sippy cup painted film) would be that the amount of lead in the paint would be determined to be higher than what I found – because the substrate would be excluded from the test. With an XRF reading in situ, the substrate cannot be excluded from the test.
The fact that I found a level that was already significantly higher (33 times higher) than the CPSC limit in coatings (which is also a level that is nowhere near the low threshold of detection of the instrument) is therefore highly supportive of the fact that the XRF is an appropriate field screening tool for a leaded coating on this sort of product – and the considerations about potentially different results when employing other testing methodologies does not negate the finding as being positive for lead, but rather confirms and supports that.
and
Here is the study that was done that does determine and identify that XRF technology IS reliable. Click the image of the study title below for the full study.
The opening summary statement of this study: ”
“X-ray fluorescence (XRF) spectrometry has the potential to accurately measure lead content in painted films on children’s products at the limits required under the Consumer Product Safety Improvement Act (CPSIA) of 2008…”
Also from the CPSC’s site – a presentation by ThermoFisher Scientific, the manufacturer of the Niton XRF that I use.
The following powerpoint presentation discusses myths and realities around the XRF Analyzer for painted films including: “XRF will not easily measure lead in thin dried films of paint in units of ppm” however further reading of this document (and other similar documents) shows that the concern is for the accuracy of low threshold readings (90 ppm) – not for significant positive readings, as were found in the Green Sprouts sippy cup painted film. Additionally the presentation goes on to discuss pitfalls and drawbacks in other testing methodologies as well as the potential or perceived shortcomings of XRF Testing. My conclusion after reviewing this document: while no testing methodology is perfect, XRF remains an effective screening tool for detecting lead paint (including lead in thin painted films) accurately in the field – (and continuing to read below – this is especially true for levels that are significantly above the limit of detection of the instrument.)
WHO statement in this document:
States: ”
“The accuracy of portable XRF devices is good, although they have a larger margin of error compared with adequately executed laboratory analysis (this is particularly true of X-ray tube–based instruments). Borderline measurements (i.e. readings that are within the device’s margin of error and are close to the established national limit for lead in paint) should therefore be confirmed by laboratory analysis.”
Please note, a reading of 3000 ppm (as I found on the Green Sprouts Sippy Cup) or a reading of 4000 ppm (as the other investigative team found on the Green Sprouts sippy cup) are significant readings and could not in any way be considered “borderline” or “within the devices margin of error” for this particular test. Additionally – this paper discusses possible limitations on testing curved and small surfaces and that “some new devices may overcome these limitations”… It is my understanding that this limitation is primarily referring to the table top models and very small curved surfaces, not to the specific and pointed testing capacities of the newer handheld devices. In my [considerable] experience, I have been able to produce consistent and repeatable testing results on curved surfaces similar to and including the Green Sprouts sippy cup interior glass liner.
and I will conclude with this…. (click the image to see the study):
Never Miss an Important Article Again!
Join our Email List