I have written this in response to a lot of questions I get from readers who follow the blogger Natural Baby Mama. Since I get the same questions and concerns “on the regular”, I thought I would address all of the concerns that have come up here in one post. Please do take the time to read it thoroughly and please let me know if any point is not 100% clear (and I will do my best to further clarify).
Question #1: Can I hire a hazard inspector to test my toys (and other consumer goods) for Lead?
If you want to hire a certified XRF operator to test your consumer goods for the presence of toxicants (including Lead) the first question you need to ask them is “What type of instrument do you use?” The second and third questions should be “Does your instrument test things in ‘Consumer Goods Mode’?” and “Does your instrument give readings in parts per million?” Finally you should ask them if they have experience testing consumer goods using XRF technology. If they don’t have an instrument that gives readings in ppm OR if they don’t have experience testing consumer goods you should call around a bit more until you find someone who meets those requirements.
What appears to be happening to readers of the blog mentioned above is that they do not understand the distinction between different types of XRF testing, and they are hiring home hazard inspectors (contractors who typically are trained and certified in using XRF technology for testing for Lead-based paint and other very-high-Lead-content finishes and coatings in houses) to test for the presence of Lead in consumer goods — when this is not necessarily something these inspectors have experience with.
A hazard assessor may offer to inspect consumer goods for you – like your child’s toys and your dishes, but please understand this: the majority of hazard inspectors are not familiar with the nuances and distinctions required for testing for Lead (and other toxicants) in consumer goods, and inspectors are truly doing customers a disservice if they claim they are qualified to test consumer goods when they do not have experience doing so.
Not only do most home hazard inspectors not have the training or experience required for testing consumer goods, but it is also very rare to come across a home hazard inspector who has access to both the knowledge base required for accurately testing consumer goods and the appropriate instrumentation (hardware) and application module (software) for testing consumer goods using an XRF instrument.
What are the differences in the instruments used for these different purposes?
COST: The instrument used to test consumer goods is a specific type of XRF instrument that generally costs 3 to 5 times as much as the type of XRF instrument used by most home inspectors. An instrument specifically designed for testing consumer goods (like the ones used by the Consumer Product Safety Commission) sell new for $50,000 to $60,000 (or more!) – with a substantial contributor to the final cost being which optional/critical software modules are purchased and installed (different software modules include soil, paint, metals, consumer goods, and others.) For testing consumer goods, a “Consumer Goods Mode” testing package – which correctly interprets and reports back metals detection spikes down to the range of single-digit ppm – is required.
The instruments used by most hazard inspectors differ from the ones for consumer goods testing in that the cost is typically between $10,000 and $15,000. This is not an appropriate instrument for testing toys and most other consumer goods – ever. Most of these instruments do not have a “consumer goods mode” and do not test in ppm. They almost always give readings in milligrams per centimeter squared, and can only accurately detect higher levels of Lead, and cannot always distinguish common consumer items with “lower”* Lead-levels from potentially Lead-free items.
* With “lower levels” in this context being potentially in the 600 to 5,000 ppm range for Lead — levels which are high enough to constitute a possible exposure risk that could be quite harmful to children.
Instrument “Source”, tube source vs. radioactive materials source:
Radioactive source instrument:
- Home inspectors typically use a type of XRF instrument that has a radioactive-source; these have a low threshold of detection that is actually very high (in the range of 0.1 to 1.0 milligrams per cm squared) and a high threshold of detection that usually caps at “9.9” (which is low and non-specific as far as high thresholds go.) This type of instrument is designed and intended for detecting significant amounts of Lead in Lead-based house paint. They are also very low-precision instruments, with a higher margin of error than the instruments used to accurately test for Lead in consumer goods.
X-ray tube based instrument:
An appropriate instrument for testing for Lead and other metals in consumer goods is usually a tube-based instrument that has software installed that specifically produces test results measured in Parts Per Million (ppm). This is very important, because the concern here is that toys (and other items intended for use by children) are considered toxic (and illegal) at paint or coating levels of 90 ppm Lead and higher. Instruments designed specifically to test for Lead in consumer goods generally test down to the range of single digit parts per million with a very high level of precision/low margin of error (also potentially in the single digits ppm range), and therefore are appropriate to be used as a screening tool in determining if the coating or surface of an item may or may not be safe for children to use.
Why readings from a radioactive source instrument that are in milligrams per cm squared don’t translate…
Even in the LOOSE interpretation for the conversion of milligrams per cm squared (from a radioactive source instrument) to ppm, the lowest possible reading of a typical XRF used by a home inspector is “0.1” (mg/cm2) – and a reading of “0.1” could still indicate something in the range of 500 or 600 ppm Lead (much higher than the modern 90 ppm toxicity level set for toys and other items intended for use by children!), and so even something approaching a “negative” (using an inappropriate XRF instrument) is not meaningful/useful as a reading – because it may actually be negative OR it may be positive (given the high margin of error of these inappropriate instruments) – just at a level below 600 ppm (and thus still very unsafe for children!).
If your inspector does not have an instrument that measures in ppm (but you are having them out for an inspection anyway) – make a note of the readings [with the understanding that, due to the inherent low-precision of the instrumentation, the readings in these ranges may not be anywhere near accurate]… and I may be able help you interpret them.
For consumer goods (especially things like dishes and toys), if a home inspector tells you an item is “negative” for Lead— because it is “less than one mg/cm2” (or even because it is “less than 0.1 mg/cm2”) – please understand they are misinformed and not in a position to make this determination with the instrument they have — as this statement under these circumstances clearly indicates they have not been trained in consumer goods testing and are likely not aware of the relevant toxicity limits for consumer goods (as distinct from the limits set for house paint to be eligible for federal funding for remediation.)
Consumer goods testing takeaway:
Please don’t waste your money hiring a home inspector to test your toys with an inappropriate instrument. HOWEVER, If you are having an inspector out to test your HOME for Lead-based paint (coatings on building components, windows, siding, interior paint, tubs, etc.), and have the opportunity to have him test a few of your consumer goods while he (or she) is there, please know that only the readings over 1.0 are useful – and anything under a 1.0 may still be very unsafe for a child to use and should be re-tested by an appropriate instrument before you make a determination that it is safe or unsafe.
Question #2. Does XRF testing”leave radioactivity behind on the items tested”? I’ve heard I have to “leave stuff in the garage for a month after it is has been tested, so the radioactivity dissipates”.
No. This claim reveals a basic ignorance of what this type of instrument is and does; it is truly akin to claiming that a flashlight “leaves behind photons” on things that have been illuminated by its beam.
Question #3. Can I be in the same room while the testing is being done? I’ve heard that “the backscatter on the instrument will cause an unsafe level of radioactivity exposure to people in the room”.
Yes, you can certainly be in the room if testing is being done properly; this is simply not a reality-based/scientifically-valid concern when the correct type of XRF instrument is used for testing consumer goods, and when that instrument is used in a normal and proper manner; if a tube-based (i.e. non-radioactive source) instrument is being used properly, there is virtually no possible “exposure risk” to people in the room.
One descriptive comparison I have heard from others who know how to use the appropriate instrument for consumer goods testing is that even if a tube-based instrument was pointed at a person’s face and held in the “on” position for 5 hours straight, that amount of x-ray exposure would be comparable to a single dental x-ray.
Even though the tube-based instruments have a very narrow range that they function in (the instrument does not function unless the item being tested is right up against the scope at the end of the instrument) rigorous safety guidelines are still followed when they are in use with others (people other than the instrument operator) in the room. In fact the guidelines that are followed were established for the operation of the other type of XRF instruments (i.e. the radioactive-source ones) — and even though they are not always fully relevant to the operation of a tube-based instrument these safety precautions are still always observed anyway, addressing any conceivable concern!
Safety precautions include:
- Always pointing the instrument away from people (so placing the object being tested on a table or counter that does not have people in the direction the instrument is pointing.) To facilitate this I often test consumer goods on a kitchen counter propped up against the backsplash of the counter – after first testing the backsplash to confirm it is lead-free. If a backsplash is not Lead-free (ND / Non-Detect for Lead) I will prop a known Lead-free piece of wood (like a cutting board) against the backsplash and test against that. Alternately some testing (on certain types of objects, especially some fragile or small objects, or large/heavy objects that cannot be moved) needs to be done with the instrument pointing down towards the floor. For small objects in this category I often prop the object being tested up on a pillow on a chair and point the instrument downward (only when limitations of the object make it difficult or impossible to test the item propped up on a counter.)
- The operator usually does an introduction prior to turning on the instrument and beginning any testing. In this introduction it is normal to ask people who will be there for the testing to stand both to the side and behind the operator whenever possible (to help ensure they will be away from the direction of the x-ray when the instrument is activated.)
- Tube-based instruments have built in safety features: the non-radioactive (tube-based) instruments only are “on” when the button is depressed, and it does not emit any x-rays (or potential scatter) when the button to initiate testing is not depressed or when the instrument is not turned on.
- Dosimetry rings (radiation exposure monitors) are sometimes worn by operators. I have a dosimetry ring to use when I do consumer goods testing. When I signed up for the monitoring service contract I asked the man with the dosimetry monitoring company how often the tube-based instruments used for consumer goods testing show any measurable radiation exposure to the operator (beyond normal background radiation exposure, even taking into account potential spikes that might be generated from other events – like flying on airplanes). His response was “never.” In his experience the XL3T XRF (tube-based) instruments normally used for consumer goods testing hadn’t ever resulted in measurable radiation exposure using his company’s monitoring devices (worn on the hand of the operator.) So one can therefore extrapolate from this that if the instrument is being used properly by a trained operator and the hand of the operator is not seeing any measurable impacts, those around and nearby are also not being subjected to any measurable impacts.
Some additional thoughts from my friend Michael (a friend and longtime supporter of my work, who also works with XRF instruments on a regular basis):
“Fission products from nuclear reactions (fallout from nuclear explosions or material released from reactor accidents) and primary radioactive materials (containing uranium, thorium, radium, etc) are radioactive particulates that can stick to things or travel as airborne dust and continuously emit radiation.
X-rays, however cannot stick to things or turn things radioactive. As Tamara says, the tube-source XRF instruments generate no radiation when powered off. The radioisotope-source XRF instruments used for lead paint analysis have a source that is always “on” but is encased in lead or tungsten shielding. Both types have radiation-proof shutters that prevent any radiation from escaping the instrument except when the trigger is pressed to take a reading. State registration requires periodic leak-testing of the instrument.”
– Michael T.
As always, please let me know if you have any questions.
Thank you for reading and for sharing my posts.
The picture below is my feet (far right),
my husband’s feet (middle) and my friend’s feet (far left.)