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Survey as well as health assessment of chemical substances in school bags, toy bags, pencil cases and erasers 3 Analysis methods and results
The following qualitative and quantitative analyses are completed as basis for an assessment of the possible health risk when using school bags, toy bags, erasers and pencil cases. 1. Screening analysis by FT-IR for determination of the materials which the products are made of as well as of phthalates and to some extent inorganic colouring agents. 2. Beilstein test for detection of the presence of C1 for identification of PVC and thus suspicion of phthalates. 3. Quantitative determination of phthalates in erasers. 4. Quantitative analysis for elements through XRF for determination of the amount of the individual metals in the product. 5. Quantitative analysis for metals in extracts at ICP-OES for assessment of the quantity of each metals migrated. 6. Quantitative analysis of which substances that may be emitted to the air by headspace analysis combined with GC-MS. 7. UV-VIS analysis for identification of certain colouring agents. 8. Quantitative analysis of which substances being emitted to artificial sweat and in one single case to artificial saliva at GC-MS. 9. Analysis of perfluorinated compounds which may have been applied as preservative on certain products. 3.1 Screening at Beilstein’s test3.1.1 Used analytical equipment and proofing methodsBeilstein’s test is a quick method for determination of halogens. The principle of the test is that volatile copper salts will colour a flame green because of the copper content. Copper halides (F is accepted) are volatile and only in a few other cases the test will give a positive reaction. If halogens are present in plastic the plastic is most probably a PVC plastic and will typically be softened with a phthalate plasticizer. A micro-burner and a strong copper wire are needed. The micro-burner must have full air inlet (nearly colourless flame). The copper wire is calcinated and the warm wire is rubbed on the sample so that some of the sample melts upon the wire. The wire is led into the middle of the outer zone of the flame. If the sample is lighted and burns it is burnt out outside the flame. The wire is again led into the flame and shortly before ignition the green colour is seen clearly if the sample contains halogens. 3.1.2 Results of the Beilstein testThe Beilstein test is conducted through a test on all the purchased products of all material types found on the individual products. The results are shown in Table 3.1 and in Appendix D. Table 3.1 The result of the Beilstein test
From the above Table 3.1 it is seen which products having a positive test. This gives a suspicion of phthalates. The presence of phthalates can be verified through a FT-IR analysis. A comparison of the analysis results for the Beilstein, FT-IR and XRF analyses is shown in Appendix D. 3.2 FT-IR analyses3.2.1 Applied analytical equipment and preparation methodsThe FT-IR analyses are conducted on a Nicolet Impact 400 FT-IR spectrometer. Initially, only a screening analysis was conducted for an assessment of the material type. If a product consisted of more than one type of material, the part of the product being assessed to be the largest/most important is analyzed. Different techniques were used depending on the product. Flat, smooth materials were examined using ATR technique. Materials not smooth or flat were investigated by rubbing a silicon carbide sand paper against the sample and absorb the spectrum at DRIFT (diffuse reflectance) with the clean sand paper as reference. Textiles were also examined at DRIFT technique with a steel surface (empty “cup”) as reference. Both ATR and DRIFT are reflection techniques and the spectra become a little distorted in relation to normal transmission spectra. For identification of plastic types primarily electronic reference libraries (Hummel-Scholl or Sadtler Know-it-all) were used in combination with FORCE Technology’s general experience. Plasticizers, such as phthalates, are normally used in large quantity (30%) and can immediately be seen in the spectra. These substances will often camouflage the spectrum of the basis polymer. Normally, a phthalate present in a few per cent of another ester may not be noted. Normally, other additives being used in 0.1% to a few per cent may not be discovered at the screening analysis unless they have absorptions in ranges where basis polymer and perhaps plasticizer for positively do not absorb. Fillers with characteristic spectra as for example chalk may be detected in levels of 10-30% while other fillers most often cannot be positively identified. In relation to anti-oxidants which are added in much less amounts than plasticizers, it will only be in the cases where more than about 0.1 weight% is added and the anti-oxidant, or other additives, has strong absorption bands outside the absorptions from the polymer that they may be recognized in the analysis. 3.2.2 Results of the FT-IR screeningThe results are shown in Table 3.2 and in Appendix D. Table 3.2 Results of the FT-IR screening
If the results of the Beilstein test stated in Table 3.1 are compared to the results of FT-IR analyses shown in Table 3.2 it is seen that the erasers showing positive at the Beilstein test mainly consist of PVC with a phthalate plasticizer. It is also seen that the bags and pencil cases showing positive at the Beilstein test mainly consist of polyester textile (PET). A comparison of the analysis results for the Beilstein, FT-IR and XRF analyses is shown in Appendix D. 3.3 Phthalates in PVC3.3.1 Analysis methodIn co-operation with the Danish Environmental Protection Agency a number of erasers have be selected for quantitative analysis for phthalates. 50 mg of the sample is weighed in fragments in 20 ml screw-top glasses. The samples are extracted with CH2Cl2 at room temperature during the night. Dissolved PVC, if any, is precipitated by addition of methanol. The sample is centrifuged and the extract is analyzed by gas chromatography with mass spectrometric detector (GC-MS). As internal standard butyl-hydroxyl-toluene (BHT) is used. For the GC-MS analyses Varian Saturn 2000 ion trap system is used. The detection limit is substantial below the identified levels. The degree of uncertainty of the quantification is approx. 10% relative. 3.3.2 Result of the phthalate analysisThe result of the phthalate analysis is shown in Table 3.3 below. Table 3.3 The result of the phthalate analysis
* Small amounts of dibutyl phthalate In the analysis, mainly two types of phthalates are identified, DEHP (Bis-(2-ethylhexyl) phthalate) and DINP (Diisononyl phthalate). No attempt to quantify small content of other phthalates has been made. Phthalate is added as a plasticizer to PVC, normally in quantities of about 30% and in some cases up to 50%. It ought to be noted that in sample 15 a phthalate content of 70% is found which is above the normal content. Subsequently, an analysis of DEHP for sample 22 to an external standard is conducted. Here the result was a content of 44 w/w% DEHP. As it is more precise to apply external standards it is a content of 44 w/w% DEHP for sample 22 which is applied in the health calculations. 3.4 XRF analyses3.4.1 Analysis method XRF analysisFor the X-ray analyses (energy dispersive X-ray fluorescence) a X-LAB 2000 instrument (Spectro) is used. For quantification of the content the programme TURBO-QUANT is used. Through this technique all elements larger or equal to no. 11, sodium, can be analyzed. The minimum level which can be determined depends on matrix and element but it is <10 ppm for certain elements. No real sample preparation has been conducted. The sample is either placed directly in the instrument or a piece of approx. 5 cm x 5 cm has been cut. These test samples are analyzed directly in the instrument. The analysis is a surface analysis, i.e. only elements within a maximum depth of approx. 100µm, dependent on the material, are analysed. 3.4.2 Result of XRF analysisThe procedure of the X-ray analyses is that an analysis of all the material types found on the individual products is conducted on all the purchased products. The amount of single substances shown in Table 3.4 is the maximum permitted emission at extraction in stomach acid according to the Toys Statutory Order. There is no reason to examine the extraction level to stomach acid if in the X-ray analyses, there is found a lower total value of the content of the metals in the products than the threshold limits of the maximum emission of the substances at extraction in stomach acid. Table 3.4 Maximum emission of single substances at extraction in stomach acid
The result of the XRF screening analysis of products is shown in Table 3.5 and in Appendix D. The result of the ICP-OES analysis to quantitative determination of selected metals at extraction in artificial sweat is shown in Table 3.7. Table 3.5 Results of the XRF screening
The XRF analysis results confirm the results of the FT-IR analysis and Beilstein test. Most of the erasers consist of PVC with phthalate as plasticizer. As can be seen in Table 3.5 the XRF analysis shows the presence of large amounts of Ca in those products which at the FT-IR analysis showed the presence of chalk. It shall be noted that the XRF analysis also shows a high content of Cr, As, Se, Cd, Sb, Ba, Hg and/or Pb in one or more products. The amount of single substances stated in Table 3.4 is the maximum permitted emission at extraction in stomach acid according to the Toys Statutory Order while amounts stated in Appendix D being the basis of Table 3.5 state the amount found in the product. The results stated in Table 3.5 and in Appendix D shall exclusively be regarded as an indication of the possibility that amounts exceeding the permitted amounts can be found in a migration analysis. The products where a high content of the above substances is found are thus selected for a more detailed analysis. Results of heavy metal contentMeasurement of the content of metals in the products is conducted through a quantitative element determination by means of X-ray analysis (see the results in Appendix E). These results are compared to the application limitation statutory orders for lead, cadmium and mercury as described in chapter 2 under Legislation. As it is shown in Table 3.6, in total four products exceed these application limitations. Table 3.6 Products exceeding the application limitations for Pb, Cd and Hg. (Sample nos. 31, 34, 40 and 42)
3.5 ICP analysis3.5.1 Analysis method ICPBarium is analyzed on ICP-OES – inductively coupled plasma optical emission spectrometry – from Jobin Yvon JY 38 S and other metals are analyzed on ICP-MS – inductively coupled plasma mass spectrometry – from Varian according to DS/ISO 17294-2. 3.5.2 Result of the ICP analysisMigration analyses for metals of selected products are conducted. The results are shown in Table 3.7 below as well as in Appendix F. Table 3.7 Results of migration analyses for metals of selected products
*TLV = Threshold Limit Value These values are to be compared with the threshold limits as stated in DS/EN 71-3 – see Table 3.4. For comparison, the threshold limits are repeated in last row in the above Table 3.7. The measured migration values are all stated in µg/l except for barium which is stated in mg/l. The threshold limits in DS/EN 71-3 are all stated in mg/kg. The conversion factor is: 1 µg/l = 0.001 mg/kg. So all numbers must be devided with 1,000 (except those for barium) to be able to compare them with the threshold limits. 3.6 UV-VIS screening3.6.1 Analysis method UV-VIS screeningIf the products contain colouring agents which can migrate to artificial sweat this will be important information whether more detailed analyses are needed. Products for UV-VIS screening are selected on basis of their strong colours. Products from all product categories are selected. The UV-VIS spectra of the extracts are recorded in the range of 800 – 200 nm on a Perkin Elmer Lambda 2 spectro photometer. Substances having an absorbance of 0.01 at a given wavelength can be detected. Substances absorbing in the range 400 to 700 nm will indicate the presence of colouring agents while substances only absorbing in UV (200-400 nm) indicate other additives like BHT, MBT, phthalates and similar. As colouring agents have different intensity it is not possible to state a general detection limit but as indication it can be informed that strong coloured agents in a concentration of 5 mg/l can have absorbance about 0.2 to 0.5 measured in a 10 mm cuvette. For the analysis a partial sample from the migration test in artificial sweat has been applied. 3.6.2 Result of the UV-VIS screeningThe sweat extracts are recorded using a 10 mm cuvette in the wavelength range of 200-800 nm. Except for sample 24, substances with strong UV absorption are found in all samples. UV absorption can derive from plasticizers (phthalates), solvent residues (isochrones) on various additives. Only three samples have an absorption in the visible range of the spectra indicating staining. One sample, 42A, has shown an immediately visible yellow colour in the extract. Two samples 4 and 38C have given a weak red tinting of the extract. However, the red tinting was so weak that it is not noted immediately. The result of the UV-VIS screening is stated in Table 3.8. Sample 41A is not analyzed through UV-VIS but shows a clear pink colouring in the extract. Table 3.8 The results of the UV-VIS screening:
3.7 GC-MS Analysis3.7.1 Analysis methodIt is observed that some of the products emit a chemical smell, especially when they are quite new. Therefore, a number of products have been selected for an analysis of which volatiles that can be emitted to the air when handling the products. The analysis is conducted semi-quantitatively by headspace technique combined with GC-MS. Screening of volatiles, headspace technique Approx. 1 g of the sample is cut into small pieces. The samples are placed in a closed sample bottle of 10 ml. The samples are placed at 40°C during the night and then left at room temperature for about three weeks. The samples are analyzed by GS-MS by use of the headspace technique. The samples are reheated at 40°C for ten minutes and are shaken at regular time intervals. Hereafter, 1000 µl of the air over the sample (headspace) is injected in the GC. For the GC-MS analyses a Varian Saturn 2000 ion-trap GC-MS system is used. At the headspace technique only substances with a certain steam pressure is observed. It must be noted that due to problems with the analysis equipment, the results from the headspace analyses are not exact but only indicative. It is assessed that the error rate is between 10 and 500%. Furthermore, the problems with the analysis equipment caused that the samples were at evaporation for three weeks and not for six. Therefore, the analysis values represent far more than typical daily values. It is difficult to asses the consequence of the extended period for the analysed values compared to a typical use situation. The evaporation will clearly be largest at the beginning and in time there will be a kind of equilibrium and the evaporation will abate. Furthermore, the temperature will have an influence. The evaporation is significantly larger at the beginning at the higher temperature than at room temperature. As quantization p-xylene is applied as external standard and it is assumed that the total-ion area for a peek proportional with the concentration with same factor as p-xylene. There are differences in the ionization efficiency and the degradation patterns of the different substances so the assumption can only give semi-quantitative values for other substances than xylene but for the same substance in two different samples a higher number will mean a correspondingly higher content. Migration to artificial sweat Artificial sweat is produced according to DS/EN 1811:2000. 2 g sample of varying area is placed in 25 ml artificial sweat and left at 40°C for 4 hours where after the water phase is decanted from the sample pieces. The water phase is examined through UV-VIS for staining and GC-MS with solid phase micro extraction (SPME) of substances migrated to the water phase. A Carboxen-DVB or a 30 m PDMS fibre is applied but a few samples are analyzed using both fibres. There is a certain difference in the concentrating efficiency for the two fibres. Furthermore, only calibration for substances in EN71-9 is used as well as four specific phthalates (DIBP, DBP, DEHP DnOP). Of the substances mentioned in EN71-9 it is in fact only isophorone which is found in the samples. Therefore, the values in the table of other substances than isochrones and phthalates are only comparable for differences between releases of the same substance for the different samples as the difference in the concentration efficiency is unknown. As the migration period is 4 hours the analysis results are divided by 4 in the risk calculations in chapter 5 when the risk of a daily exposure of 1 hour is calculated. Migration to artificial saliva According to agreement with the Danish Environmental Protection Agency a migration analysis to artificial saliva is carried out on eraser 22. Artificial saliva contains in 1000 ml 4.5 g NaCl + 0.3 g KCl + 0.3 g Na2SO4 +0.4 g NH4Cl + 3.0 g C3H6O3 + 0.2 g Urea dissolved in demineralised water where after pH is adjusted to 5.0 with 2 N NaOH. The extraction is made of 1 g sample in 20 ml saliva at 37 degrees for 1 hour to imitate a child sucking the eraser for 1 hour daily. Thereafter the saliva is made alkaline, pH 10, and extracted 3 times with dichloromethane. The extract is dried with sodium sulphate and then evaporated to dryness. The residue is dissolved in 1 ml dichloromethane added tetradeutero-bis(2-ethylhexyl)-phthalate as internal standard. 3.7.2 Result of GC-MS screeningThe result is shown in Table 3.9A and Table 3.9B Table 3.9A The Head-space analysis
Table 3.9B GC-MS of the sweat extract analysis – [µg/g]
Number: Number of products in which the substance is found. If the substance is found in two different examined parts of the product (for instance A and B) it is only counted as one product. Max: Maximum concentration in which the substance is found. Migration to artificial saliva The result of the migration analysis of eraser 22 is that 0.1% (w/w) DEHP or 1 mg/g eraser is emitted to artificial saliva, i.e. that the concentration in the saliva was 0.05 mg/ml. Uncertainty of measurement is 50%, i.e. the real value is between 0.05 and 0.2%. Screening of volatiles, headspace technique By screening of volatiles through headspace technique the following 23 substances of particular interest are identified. The selection of substances for health assessment is based on the classification of the substances and description of effects which may be potentially problematic for the consumer if the migration of the substances from the products is too high.
Migration to artificial sweat The following 25 substances of particular interest are identified through migration in artificial sweat and GC-MS analysis. The selection of substances for health assessment is based on the classification of the substances and description of effects which may be potentially problematic for the consumer if the migration of the substances from the products is too high.
3.8 PFOS analysisPerfluoroctanesulfonate (PFOS) and a number of associated perfluorinated compounds are applied in many industrial products and consumer products due to their special chemical properties, for instance the ability of repelling water and oil. An increasing concern over these potentially harmful compounds has arisen as they are now found as globally widespread pollutions in air, water, soil as well as flora and fauna which indicate that these perfluorinated substances are environmentally persistent and accumulate in animals and humans. PFOS and associated substances are easily absorbed in the body where they can be connected to proteins and especially accumulate in blood and liver but with regard to some compounds also in testicles and brain tissue. The half-life period in the body seems to be several years. The acute toxicity of PFOS and PFOA is moderate and the first-mentioned is most harmful to health. The toxicity of the associated substances increases with the chain length. The liver is the primary target organ of perfluorinated compounds and they generate peroxisome proliferation in rat liver as well as induction of different enzymes involved in the metabolism. PFOS seems to be more active than PFOA regarding this effect but again PFDA with a longer alkyl chain is even more active. PFOA and PFOS also have an influence on the blood level of various hormones, for instance by decreasing the testosterone concentration and increasing the concentration of estradiol in rats. Therefore, the substances must be regarded as hormone-disrupting (endocrine disruptor). PFOS may be applied as impregnating agent in certain products, especially bags might contain PFOS. Therefore, a number of bags are selected for analysis for PFOS. 3.8.1 Analysis method PFOS analysesThe samples (2 g textile cut into small pieces) are extracted by use of methanol, diluted with water followed by centrifugation. The extracts are analyzed using LC-MS-MS with electrospray. 3.8.2 Result of the PFOS analysisTable 3.10 Result of the PFOS analysis
Ten selected products were analyzed for a possible content of perfluorinated compounds. The analyses showed that all measurements were below the detection limit. 3.9 Summary of the analysis resultsA wide selection of the school bags, toy bags, pencil cases and erasers being on the market today has been analyzed. The analyses have mainly shown that:
The 10 products selected for analysis of perfluorinated compounds showed that all measurements were below the detection limit. In total four products exceed the application limitations for lead, cadmium and mercury as described in chapter 2 under Legislation (no violation for mercury). In the selection for a more detailed health assessment/risk assessment emphasis has been on selection of the substances having harmful properties.
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