Hello everyone! I would like to welcome you to SPEX CertiPrep’s Webinar, “Identification, Preparation and Analysis of Imported Plastic Children’s Toys for Restricted Elements”. My name is Amy Williams and I’m the marketing manager here at SPEX CertiPrep and I’ll be moderating the presentation today.
Before we begin, I just want to get a few housekeeping tips out of the way. If we want an attendance, won’t we see emails with the presentation slides and also an email with a link of the webinar recording on our Youtube channel. And that will probably go out next week. Slides will go out today or tomorrow morning and the recording will go out next week. If you have any questions during the presentation, please type it in the question box on your screen and we’ll answer them during the Q & A session after the presentation.
I’d like to introduce our speaker today, Patricia Atkins. Patricia is the products’ applications specialist for SPEX CertiPrep and I’m sure that a lot of you recognize her as a regular from our number of our cast webinars and research projects including the trace elements in lipstick, the chemistry of wine and bpa and phthalates in plastic toys.
Thank you very much and I would like to welcome everyone to our presentation this morning. If you are gonna be at ASM as we also welcome you to stop by our post tour, we’ll be having a post tour on this top at this upcoming ASMS meeting in Baltimore.
I’d like to get started, just talking a little bit about the toy industry and its importance to study different toys because of their impact on our economy as well as the impact on our children.
First of all, the toy market worldwide is a very big business of 84 billion dollars a year and the U.S is the single largest importer of toys from 22-35 billion dollars a year. More than 75% of the U.S toys here are actually produced in China and these products, toys and other Chinese products included account to more than 60% of all product recalls. China also supplies more than 81% of counterfeit goods seized by customs like our friend, the doll here. What’s amazing though is only a very small percentage of all of these toys that come into the U.S are actually rejected for exceeding limits. From 2010 to 2014, there are, on the CPSC website14 toy recalls for specifically for chemicals and lead.
The toys’ cells are composed of many different types of polymers from ABS type of plastic, which is a hard material that’s usually molded. It’s most commonly seen in things like legos or building bricks. The softer plastics like PVC or some durable plastic like polyethylene. You can have a toy like the car here, which is composed of many different types of polymers all put together.
What’s the concern is that these toys contain a lot of hazardous materials as well as being physically hazardous to a child. These toys contain things like heavy metals, phthalates and bisphenol A. And these restricted compounds and elements can be found almost anywhere in the toy. The paint on the stickers, the paint applied to the plastic themselves, the polymer that the toy is made out of and if the toy contains an electronic component, then you have RoHS and WEEE directives governing the different heavy metals in electronic components.
Mostly, when we think of heavy metal exposure on children from toys, we hear about lead. Lead has been famous for being a case of poisoning on children, mostly because lead poisoning is associated with paint. Now, lead paint was banned from home use in 1978. But 25% of U.S homes with children. Lead paints, especially lead (II) chromate in chrome yellow and lead (II) carbonate in white lead are primary formulations of lead in paint.
Another potential source of heavy metal contamination in children is cadmium. Cadmium is the by-product of Zinc smelting but it’s also used as a PVC stabilizer and a colorant.
Used as powder screen coloring. Chrome (VI) which is found in chemically-treated wood, steel manufacturer and other colorants. And there’s Antimony which is a catalyst for polyethylene teraphthalate and flame retardants. Finally, there’s barium that’s used in different paints. In the E.S and in Europe, there are regulations regarding lead, lead in paint layers, metal content in children’s toys, total lead levels, migration of lead and other elements from children’s toys and the limits are very similar. The most notable limits are the limits for lead, which are about 90 µg/mg/kg.
There are two types of ways to study the lead and other content of children’s toys and paint. There’s a migration which is tested by leaching the material in a matrix that simulates hydrochloric acid systemic contents and then there’s the total amount where the total amount of a bent element is measured in total toy weight. Over the last few years, the levels of acceptable lead have dropped from 300 ppm 90 ppm.
For our study, we had 26 toys from dollar or discount stores. We separated them into their component parts which gave us over 65 different samples. We tried to choose items that were designated for oral contact, meaning that they were designed to be placed in the mouth. Things like our funny teeth, our whistles, our snorkel. Then there are items that are suggested to have high probability of oral contact or mouthing by small children, these are items that within reason will be placed in a child’s mouth during play. Things like our rubber duck, our doll and our toy soldiers.
The toys were disassembled to their different components of different polymers, so our truck here, the wheels were taken off, the silver seats inside were separated, the stickers were removed and when it was possible, we tried to separate the paint from the underlying polymer to use that as a separate sample.
We also did a homogeneous grinding of parts of the toy using our SPEX SamplePrep Freezer Mill and liquid nitrogen. We cut 2 ½ grams of plastic into about 5 millimeter decreases and then ground it into fine powder using liquid nitrogen and cycles of pre-cooling cool.
What this gave us was a fairly homogenous powder and you can see that part of our subject was a nice fine powder. Our whistle and our teeth also gives a fine powder. Now, we had used these toys in a previous study that we referenced a year or so ago where we did organic components on these toys and in that study, we were following a CPSC method which the toys were suggested to be cut into under 5 millimeter pieces. We were not sure if the actual size of the particles was going to greatly affect our extraction at that time so we did a little study and we extracted 5 millimeter piece, 2 millimeter pieces and dome powder and we can see that we got a lot more extract on that powder than we did in the larger chunk pieces.
When it comes to sample digestion, affine powder is a little easier to digest or at least uniformly digested compared to a large 5 millimeter or 2 millimeter piece. Our next step was to try to decide what type of polymers these different toys fell into. This is an identification chart of the most common polymers in use with their recycling codes. And we have things like polyethylene terephthalate which is most commonly known as soft drink bottles and primary dangers from PETE are acetaldehyde and antimony which are used or by-products of manufacture.
And you have your polyethylenes, your high density and your low density polyethylene which we know is in milk jugs, bottles, shopping bags, but they’re also components of many toys. Now, overall the literature, there’s not a huge amount of phthalates or other additives in these polyethylene materials. So they’re considered to be a little bit cleaner on the scale of, at least in organics, the cleaner for some of these potentially dangerous elements of compounds.
We also have PVC which is, on the other hand, notoriously dirty organic compounds. This is pipe, shower curtain, especially toys, they are considered to be soft toys. And they are loaded with Phtalates, Bisphenol A and especially heavy metals.
Some of the other polymers are not quite as common. Polystyrene, polycarbonate, ABS, which I’ve mentioned before is most commonly known because they’re a component of legos. And they each have their different dangers or hazards. So for us, the first step in identification is to see if there was any recycling works on our toys and unfortunately, there wasn’t. That left us with a bit of debate of how we go about identifying our different toys and now there are a lot of analytical tools that could be used to identify plastics, FTIR, IR. Not having one those instruments in our laboratory, we decided to go kind of old school and we compiled the chart of the different physical and chemical characteristics of each of the different polymers and we then done testing each of these physical and chemical criteria and narrowing down to our choices to what kind of polymer they were.
Overall, it came down to a spreadsheet or a flow chart that looked like this. Don’t worry if you can’t read all the fine print. I’m going to be a little bit more detailed. But this is the overall scheme of things. The blue boxes were density tests where we tested the plastic against a certain density standard. The pink triangles, or the pink diamonds were solubility tests where we tried to dissolve our plastics in some different types of solvents to see if they were soluble or not. And the yellow triangle at the bottom was a flame test where we actually set fire to some of the samples using a copper wire and observed what types of residues, smoke, or flame color it produced.
So, I guess the first step in this process was the density test and the easiest one was the density test against water which was able to separate our plastics into if they were the lighter plastics like the polyethylenes and the polypropylenes or if they were the heavier plastics like the PVC, polystyrene and the polycarbonates. From that point, we took those plastics and we tried some solubility tests such as in DCM that was able to derive out the polyethylenes which are very insoluble in almost all solvents to something like an APS or a polypropylene which was soluble in DCM. Then, we did more density checks to find out if it was a low density or a high density polyethylene or if it was a polypropylene or an ABS plastic.
Finally, when we were looking at the other sides, some of the heavier plastics again, we’ve done some density checks to bring it down to the last level where we did the flame test to prove if it was PVC or not because PVC burns with a green flame.
So our sample identification was as follows. Most of our toys were polyethylene toys, either LDPE or HDPE toys and PVC. We had a few plastics represented some polycarbonate, a few polypropylene, one ABS toy, silicone and some poly cloth. We were not sure of the combination but it was some fort of cloth material probably polymer-based.
Since notoriously, PVC toys are very dirty with organic contaminants like phthalates, we thought this was the best place to start looking for heavy metal contaminants. So some of our PVC toys turned out to be some of these dinosaur figures, our friend, the rubber duck, the teeth and the snorkel. The teeth and the snorkel were particular interests because they’re meant to be put in the mouth. We also had some cartoon figures that we blurred out the identities to protect the innocence.
If you’re interested in some of our previous work on the organics, like phthalates and bisphenol A on toys, you are more than welcome to get our webinar on sample preparation, extraction and analysis of imported children’s toys for phthalates and bisphenol A. I’m gonna give you a little snapshot, this shows you why we decided to pick these PVC toys.
During that experiment, we were basically following the regulations from around the world, from the U.S, from the EU, from Japan, when it came to six banned or restricted phthalates, the DEHP to the DNOP. In the U.S, we’re allowed up to .1% of each of these phthalates, especially the ones with oral contact, things in the pink. Those are the ones that we have 0.1% of each of this. In EU and in Japan, you’re up to 0.1 combined for the different groupings of phthalates.
Here is the snapshot of what we’ve found in our PVC toys. If you see the orange dotted line, that’s the U.S limit, that’s a 0.6 total, and most of our toys, barring about 4 of them are, of our PVC toys, exceeded the limit that would be allowed for the U.S to be sold because of these restricted phthalates. Most troubling is that pink snorkel, which is way above the U.S limit and as is actually meant to be put enough. The purple dotted line is the EU limit and this is the lower limit that 0.1% or total.
So overall, what we’ve found is we found several different phthalates but the DEHP was actually our most-detected phthalate and was in 15 out of 17 of our toys. 12 out of 17 of these PVC toys exceeded the CPSC limit of 0.1% and would not have been allowed to be sold here in the U.S.
So, we decided that this would be our first contestants in testing our metal content.
Our first experiment was a digestion experiment. We used our CEM Mars 5 microwave with Easy Prep vessels, 0.1g sample with 10mL of nitric acid and a pretty standard ramp temperature up to 210°C with a 15 minute Hold. What we did find, that some of our PVC samples, not all of them, but some of our PVC toy samples did not digest completely despite having tried digest them several times. This could be because there are certain additives that prohibited the complete digestion or maybe the additive saved themselves, maybe we should have brought the temperature up in order to digest that additive. But not knowing what some of these potential plasticides or additives were, we did have some incomplete digestions. We handled that by a very normal way of taking our sample residue in filtering it and then drying it.
For our standards, of course we used our CLMS suite of standards for ICP-MS and our RoHS/Weee Standards. We used high purity, very high purity nitric acid and high purity HCl to eliminate any potential contaminants.
Our study was done using an Agilent ICP-MS 7700 with a cyclonic spray chamber and a meinhard nebulizer. We did perform a collision mode with helium on our samples to try to avoid some of the polyatomic interferences.
We were able to monitor a large suite of elements but we really focused on the connotation of the restricted elements. And you can see that we did have a large suite to look at, most of the time we were looking at these elements for potential interferences.
So our first digestion, this is a snapshot of our first digestion, it was a little anticlimactic to be honest. We were expecting huge amounts of lead. We had read papers, we have done background research, we have expected a large amount of lead in our samples. What we found was that the lead levels were definitely way below what was allowed. We did try to find some paint samples, but it is very difficult to isolate just paint samples from the polymer underneath and in many cases these toys have been used in another study earlier and by the time the metal study came around, there might not have been a lot of paint in some of the area to isolate a large enough sample to give us analytical results.
Two results that did catch our eye though was a large amount of barium which was found in our duck and donkey samples and some antimony which was found in our snorkel. Now, the antimony found at 40g/kg is under the limit of 60mg/kg but for having a toy that’s being placed in the mouth, that’s a pretty high result for a toy that is meant to go on a child’s mouth and has to stay in contact with that mouth.
So then we decided, okay we didn’t quite see what we were going to see, so let’s try a different attack to it. So we chose a migration method. We also expanded to look at some of the other types of polymer or some of the other toys. We chose some HDPE and LDPE toys, our action figures, some of our toy car parts and our baby sippy cups.
We also looked at the paper stickers from the car, the doll’s dress, the flute with the medallion which is also meant to be put in the mouth and we decided to retest our friend, the rubber duck, who was basically one of the cooperates in our organic study.
For this study, we based it on the EN 71 Migration/Extraction method. We did use our CEM mars microwave system again with our Xpress vessels, 1 gram of sample and 10 mL of 1 mm HCl to stimulate a gastric fluid environment in a child’s stomach. It was run at 37°C with stirring in two hours in darkness.
One of the problems we found came down to the calculations of how you interpret these results. Because the samples are extracted or migrating from the toy into the matrix, you can calculate it into two ways. Now, there are instrument app notes and different app notes from vendors that suggest they were following a filtration/dry weight method where they took the sample after they have been extracted and they filtered it and took that filtrate, dried it out, then reweighed it and that became the basis of their calculation.
For us, that was a very very small amount. The amount of that actually extracts into the matrix to about 10mg, a very tiny amount. There’s potentially a benefit because you’re seeing the actual portion that migrates into the matrix. But anytime you have to dry and reweigh your samples, you exponentially increase your error. The more common way of looking at it and the way prescribed by the EU is looking at the total weight of the sample or the total weight of the plastic that you put into your extract. For that, that was 1g. This overall takes your results though and spreads them across that 1g sample.
If we take a look at the dry weight, that very small, tiny amount, we can see that almost all of the toys actually exceeded the barium limit, the chromium limit, only a few exceeded the lead limit and some of them also exceeded the antimony limit by factors. I’m not entirely sure that this is an accurate representation of what the concentration might actually be in a child’s system.
If you look at the total weight of calculating it, most of the results do fit within the limit allowed. The only exceptions are for barium where we find the duck again became the villain of our story with 5000 mg/kg of barium. The silver seats in that little car were at a thousand, just at the limit. We also had antimony which was higher than almost all of the samples we tested in the doll’s dress. Now, it did not exceed the limit for antimony but it was much higher, an order of magnitude higher than our samples.
Now, it’s two studies under our belt and let’s do a follow-up. We’ll do a second digestion of some of the more interesting toys from the first two runs. We did our cars, we did our doll’s dress and a few of the other items. What we did find is when we did our second digestion, those barium levels did fall below the limits. But the antimony levels in that doll’s dress went way up. So the antimony was there in the sample but was not actually migrating into the extraction. So the antimony in that doll’s dress was 301.
If we look at the comparison of the digestion and migration results, here we have our silver car seats. For the digestion, all of the results actually do fall under the limits, but the migration shows that the barium actually migrates up to the limit for the silver car seats. Our friend the duck, the barium levels in the migration seem to be very high while all the rest of the other results fall into other limits. It seemed like the higher barium levels were found in our migration studies but things like the arsenic are only slightly higher in our migration studies over the digestion. Things like cadmium, chromium and mercury were at very similar levels no matter what it was migration or digestion. The antimony and lead levels though were clearly higher in the digestion rather than in the migration.
Here’s our doll’s dress where we can see that antimony, which was a little high in the migration but was very high in the digestion and in our migration study, the barium would exceed the limit of the digestion was definitely undergoing.
So some of the challenges that we found from analyzing toys for metals, there were digestion challenges. It’s very difficult to predict whether all polymers are going to dissolve especially when the polymers are from different sources and contain different additives which sometimes change the chemical composition that makes it more difficult to digest. Also, determining the residual weight of any under-digested material can be a problem and adds source of impair to the calculations. And it is very, very difficult sometimes to separate the polymer from the paint for analysis. It was difficult when scraping the paint off, not to get the underlying polymer into your total sample weight. As I’ve said before since we have a limited amount on our samples, sometimes trying to collect the paint to get a result was a difficult process.
For the migration, you have different cited ways of calculating the analytical results. We found that not all elements were actually migrated at the same rate when compared to digestion.
Then there’s, how do you test your toy? Do you do surface coating testing? Do you look at the total toy amounts? Or do you do a migration study? There’s also the problem that there’s not a lot of matrix match standards for paint and different toy polymers in order for you to really understand what your recovery is in either extraction or digestion.
In conclusion, the lead levels we were expecting to find very high in these toys were all within the specifications despite whatever method we used with digestion and total weight. We have been able to isolate more of the paint samples or we had a bigger sample batch to collect a larger sample size of the different paints that might have changed. As the toys were ground homogenously in some cases, while we did try to isolate a small amount that just wasn’t enough for us to find the lead in our extracts that we digested. It was not possible to see any necessary lead in those paints.
Our dry weight migration methods had results for above all the limits for almost all the targeted elements. I have a suspicion that this is probably not the best way in trying to calculate this type of information. The highest elements we did find overall were barium and antimony. Barium being in our friend, the rubber duck and the silver seats of the car. Antimony being in the dress and a little bit concerning was also in the snorkel.
The total weight and the digestion methods were comparable for several elements including the cadmium, the chromium, the mercury. What we did find was the antimony was often high in almost all the digestions while barium seems to really migrate quite well into the extracts so for the migration study, barium is the highest.
I would like to thank all the SPEX SamplePrep Staff who helped me grind our toys with our freezer mill and all our SPEX CertiPrep chemists and analysts who helped do the ICP-MS analysis and helped me with my samples. I think we have time for a few questions.
Yes, that’s right Patty. Thank you very much. We have some questions from the audience and we’ll go through them right now.
Q: So the first question we have is “What country where the toys you studied from?”
A: We got toys from dollar stores and it was not by design but by accident that all of the toys we picked up seem to be from China. I don’t know whether if it’s just most of the products in that store are from China but all products were from China that we worked at.
Q: Did you test any brand-named or U.S-made toys?
A: As far as I know, these were all just cheaper dollar-store toys. We purposely did not look at some of the more expensive toys. First of all, trying to get the budget to get 20, 30 or 40 dollar toy of 20 or 30 of them at a time would have been cost-prohibited for a small study like this. In honesty, the dollar store toys were a large access to the public, so we wanted to see what was passing through a lot of people’s hands. I know, being a mother of a small child, it’s very easy when you’re going to a discount store to pick them up a cheap toy and just hand it to them then buy something off of a shelf than pay 5 times the price so we really just focused on the cheap dollar store toys.
Q: Are you planning on following up with any of the brand-named U.S made toys?
A: There has been a lot in the news about different brand-named toys, the industry for themselves just try the police themselves, they are actively engaged in a lot of toy-testing to make sure they are compliant. My concern was that the smaller toys, which do kind of pass under the radar were the ones that had the biggest potential to expose children to these dangerous elements so at this time we don’t have any plans to follow up with some more of the toys but you can go to most of the toy manufacturer’s websites and you can see if they’ve had any toy recalls. They’re pretty good at keeping up with their recalls and their different warnings.
Q: Is it possible that the results can change by analyzing the chunks components of the toys rather than grinding them?
A: Absolutely. We chose to look mostly at the ground samples because as I’ve said before, this was a two part study. The toys were first used in our inorganic study where the paint is not as much of a concern in the sample itself so the toys, for the most part, not all of it, were ground. So that made that accessible for the next part of the study. In some cases, also making an analytical choice in the laboratory, for a toy-testing laboratory or consumer-testing laboratory, which part of the toys do you sample? Do you sample the part with the red paint? Do you sample the part with the back paint? Do you try to composite them altogether? Do you try to separate it out? As I’ve said before, my hats off to any laboratory that has to separate paint from toys because it is a very tedious process and it can be very time-consuming and sometimes it’s takes hours of work and you don’t get enough samples to give you a really good analytical result.
Q: Okay, and we have time for one more question which is one that I can help answer. The question is, Is it possible to get a copy of the phthalates slides presentation?
A: Yes, it is possible to get a copy of that and what I’m going to be doing is sending all of the registrants from today’s webinar a copy of the slides of this presentation and the previous presentation as well. Then in a week or so, we’ll have the webinar on our Youtube channel and I’ll also send all of the registrants a link to that as well.
But I wanna thank everybody for coming to the presentation today and I also wanna point out that SPEX Certiprep is glad to be celebrating our 60th anniversary this year and with this anniversary we do have a new catalogue available which is 2014-2015 inorganic and organic catalogue and it’s available online and also, if you would like to receive a hard copy of this catalog, please email me. My email is actually in the previous slide here at email@example.com and I will be glad to send you a copy of the catalog. But again, thank you very much for attending the webinar today and we hope you find it informative and interesting.
The recording of our webinar entitled, "Identification, Preparation and Analysis of Imported Plastic Children's Toys for Restricted Elements."
Topics of discussion include:
• Plastics Identification
• Sample Toy Preparation
• Sample Digestion
• Analytical techniques for determining elemental content
• Correlations between restricted organic content and inorganic elemental limits