X-ray Fluorescence Spectroscopy (XRF) as a Public Health Screening Tool for the Presence of Hazardous Chemicals in Plastics Jeff Gearhart Ecology Center, Ann Arbor, MI Research Director Hans Posselt Ecology Center, Ann Arbor, MI Senior Scientist
Presentation Outline Why screen for hazards in plastics XRF testing Overview Validation Product screening Cars, car seats and toys Consumer guides to products Fate of PBDEs in vehicles Conclusions
Why screen for hazards? Toxic chemicals in plastics & people Increasing public interest in chemicals in products Increasing use of voluntary certifications Regulatory restrictions Market pressure from manufacturers & retailers: Manufacturers: H&M, Nike, Interface, Herman Miller Retailers: Walmart, Kaiser Permanente Government and institutional purchaser are growing more environmentally aware
Chemicals in People
Toy Standards
TUV SG Label
Oeko-tex Standard 100
Problems Lack of safety testing of majority of chemicals Underclassification (or mischaracterization) of hazardous compounds Continued use of hazardous products Inadequate incentives for new product development Inadequate disincentives for continued use of problematic compounds Lack of information about chemical composition
How Toxic are the Unknowns? h ~40% of NEWLY REGISTERED chemicals hazardous h QSAR evaluations suggest 44% of 42,000 EINECS (European existing chemicals database) chemicals are classifiable (cf. Danish EPA report, 2002) AND h ~15% of ~1000 EU hazardous chemicals are underclassified (cf. Swedish report, 2003)
X-Ray Fluorescence (XRF) Methodology
XRF Sampling
Advantages of XRF Testing Non-destructiveness High speed (10-30 sec) Ability to screen finished consumer products Portability Low cost compared to traditional methods Applicability to a wide range of media, e.g. soil, alloys, plastics, fabric, etc. High correlation with conventional analytical methods (GC/MS, AA)
Pb-XRF Comparison with ASTM 3335* Samples are converted to ash at 450 C for 60 min and digested with nitric acid/30% hydrogen peroxide Lead analysis by traditional means, e.g. atomic absorption (GFAA) Correlation coefficient: 0.994 XRF: MDL 2.5 ppm GFAA: MDL 0.7 ppm *D. Cappelini & W. Stopford, Duke University, November 2008
Total Lead Content of Plastics Tested by X-Ray Fluorescence (XRF) and GFAA after Charring and Nitric Acid Digestion Description XRF Result (ppm) Muffle Furnace/Nitric Acid/GFAA (ppm) Vinyl Notebook Sleeve (Various Colors) 25 25 Vinyl Notebook Sleeve (Various Colors) 223 238 Vinyl Notebook Sleeve (Various Colors) 239 229 Vinyl Notebook Sleeve (Various Colors) 2845 2989 Vinyl Notebook Sleeve (Various Colors) 25 43.7 Vinyl Notebook Sleeve (Various Colors) 25 13.9 Vinyl Notebook Sleeve (Various Colors) 406 475 Vinyl Notebook Sleeve (Various Colors) 25 13.1 Vinyl Notebook Sleeve (Various Colors) 1972 1969 Vinyl Notebook Sleeve (Various Colors) 25 6 Vinyl Notebook Sleeve (Various Colors) 25 9.2 Vinyl Notebook Sleeve (Various colors) 25 4 Marker Plastics (Various Colors) 731 850 Marker Plastics (Various Colors) 607 870 Marker Plastics (Various Colors) 310 350 Marker Plastics (Various Colors) 321 210 Marker Plastics (Various Colors) 298 260 Marker Plastics (Various Colors) 431 490 Marker Plastics (Various Colors) 954 990 Marker Plastics (Various Colors) 871 870 Marker Plastics (Various Colors) 437 335 Marker Plastics (Various Colors) 298 265 Marker Plastics (Various Colors) 623 620
Linking PBDEs in House Dust to Consumer Products using X-ray Fluorescence; J. Allen, M. McClean, H. Stapleton, & T. Webster; 03/04/08
Vehicle Br: XRF & GC/MS Seat dust collected by vacuum from 60 vehicles (Lagalante*) Good correlation between Br (XRF) & BDE-209 in dust Additional work looking at additional model ongoing *Polybrominated diphenyl ether (PBDE) levels in dust from previously owned automobiles at United States dealerships. Lagalante et al, Environment International, December 2008
XRF Results with Multi-layer Materials Table 4: Examples of XRF Results with Multi-Layer Materials Vehicle Component Br (ppm) 1996 Dodge Neon Full Seat (Cloth) Seat Foam Only Fabric Only Outer Surface Fabric Only Inner Surface 1993 Mercury Grand Marquis Full Seat (PVC) Seat Foam Only Fabric/PVC Outer Surface Fabric/PVC Inner Surface 1998 Oldsmobile Silhouette Full Seat (Leather) Seat Foam Only Leather Outer Surface Leather Inner Surface 21,300 89 62,400 77,400 87 8 192 34 4,181 10,100 2,780 2,564
XRF Sampling of Vehicle Components X-Ray Fluorescence Spectrometer (Innov-X) h 11 different components h Elemental composition h Analysis of 450 2006-2009 models
Auto Interiors Unique Environment Temperature: 190 0 F UV & Visible Light Exposure Occupancy: 111 minutes per day
Polybrominated Diphenylethers (PBDEs) Deca-BDE most prominent use in vehicles and furnishings Deca-BDE breakdown from UV-exposure, forming toxic congeners High levels found in house and vehicle dust Developmental neurotoxicity, potential carcinogenicity (EPA) Deca-BDE levels in vehicle dust: Gearhart et al. (2006): 10 ppm Lagalante et al. (2009): Average 272 ppm, Median 48.1 ppm Deca-BDE breakdown study in cars
Typical Sampling Locations in Vehicles 2007 Chevrolet Silverado
BFR Use in 2008-2009 Vehicles Percentage of Components with Br Contents >1000 ppm
BFR Results in 2008-2009 Vehicles Percentage of Components with Br Contents >1000 ppm, By Manufacturer
Number of Br-Free Vehicle Components Components sampled: 2,069 (2007); 2,410 (2008) Models sampled: 162 (2007); 218 (2008)
Elements Found in Toys Lead Detected in 2008 Toys (1,528 Products Tested) Detected elements Cadmium: 38, or 2.5% Arsenic: 289, or 18% Detected polymers Chlorine/PVC products: 406, or 26.6%
Problems cannot be solved at the same level of awareness that created them. -Albert Einstein
The design of chemical processes and products to reduce and/or eliminate substances hazardous to human health and the environment.
The Green Chemistry Opportunity
Benefits for Business New markets for safer & greener products Easier introduction of new chemicals onto the market, incentives for development & innovation This is the only benefit that has been calculated More predictable regulatory system (for planning) Reduced risk of future liability lawsuits, e.g. asbestos Increased trust among consumers, employees, communities & investors, leading to a more positive business environment Improved transparency & communication through the supply chain will lead to increased power & confidence for downstream users
Contact Information Jeff Gearhart Research Director Ecology Center 734-761-3186 x117 JeffG@ecocenter.org Hans Posselt Senior Scientist Ecology Center 734-761-3186 x113 HansP@ecocenter.org