Tracking toxic gases penetration through firefighter's garment

1. Tracking toxic gases penetration through firefighter's garment Ge Li , Vesselin Shanov, Mark J. Schulz, University of Cincinnati Andrew Schwartz, LION Apparel Inc. William Jetter, Sycamore Township Fire Department

2. Outline Background and Objectives Our Approaches Results and Discussions Conclusion Future Work

3. Background • Firefighters are exposed to chemicals and by-products of combustion • The fire environment becomes more risky due to new technology, i.e. chemicals used in hybrid automobiles and furniture • Fatal injuries reported is increasing annually • The toxic threats: CO, HCN, HCl, H2S, etc induces sensory irritation of eyes and bronchial irritation and heart attack • Garment is critical for protection • Frequent exposure of the garment causes deterioration • Absorbed chemicals in garment act as a secondary source of hazardous exposure

4. Background Typical Firefighter Garment Outer Shell Layer Resist ignition & protect internal layers from rips, tear, abrasion, etc Moisture Barrier Layer Preventing external water from penetrating into garment Complete system of four components Air Layers and Thermal Barrier Layer Create insulation by air spaces within the layer & bring comfort and mobility Moisture Barrier Layer Provide the seam strength to hold the whole garment together; ‘wick’ perspiration off the body and bring comfort

5. Possible Damages to Fabrics During Fire Event: Thermal Damages (Crease, Shrink, Deform or partly Melt) Chemical Damages (Decompose, Dissolve in Acid) Mechanical Damage (Graying, Worn out) Background

6. Objectives • Study representative samples and analysis the types and quantity of absorbed chemicals • Create a profile showing how these toxic gases penetration through firefighter’s garment • Generate data and provide information about durability of fabric • Find out the possible mechanism of deterioration caused by absorbed chemicals

7. Outline Background and Objectives Our Approaches Results and Discussions Conclusion Future Work

8. Sample Collects Sample Set 1: Blank (never exposed to fire) New garment fabrics (4 layers) Received from Lion Apparel Inc. Sample Set 2: Used (exposed in fire-ground for 18+ hours, not washed) 6x3 inch garment coupon (only outer shell layer) Received from Sycamore Fire Department Sample Set 3: Retired (Used for 5 years, washed quarterly) Old Piece of clothing cut from retired firefighter’s garment (4 layers) Received from Sycamore Fire Department

9. Methods EAG Lab • GC/MS(Identify fractures of different substances within a sample) • XRF (Analyze concentration of Chlorine as well as others) • IGA (Analyze C,H,O,N,S in volatile form under high T) • ESEM & EDS(Micro-Morphology study) • Tensile Testing(Mechanical properties testing) • TGA(Thermal properties analysis) UC

10. Outline Background and Objectives Our Approaches Results and Discussions Conclusion Future Work

11. ESEM & EDS • Fabric appearance is one of the most important aspects of fabric quality • Micro-structures on fabric surface • Environmental Scanning Electron Microscope (XL30-FEG ) is a microscope with 2 nm ultimate resolution. The Peltier stage may be utilized to keep samples at 100% Relative humidity while they are being imaged. • Energy dispersive X-ray spectroscopy (EDS) is an analytical technique used predominantly for the elemental analysis or chemical characterization of a specimen.

12. Outer Shell Layer (New) Outer Shell Layer (Retired/old) EDS Foreign particle composition

13. ESEM (Thermal Barrier Layer) New Old

14. ESEM (Face Cloth Layer) New Old • No significant difference between new and old face cloth layer

15. ESEM & EDS (Summary) • At outer shell layer, foreign particles were attached on to the fibers; we also found peel-offs and split like (more voluminous and hairy) on the surface of used fibers • The chemical composition of foreign particle contains S, Zn, Ca, Mg • Peel-offs and hairy structure could also be found on old thermal barrier layers • No significant differences of face cloth • Note: Si and O is always there because of the environment inside ESEM. We coated the sample with Au (Gold) in order to get the sample conductive and get good ESEM images.

16. Tensile Test • Fundamental type of mechanical test • Showing how it reacted to the forces being applied • Equipment: INSTRON 4206 ASTM Standard Test Load Speed: 0.25inch/min; Spec. Gauge Length: 1.495 inch; Holding Width: 0.52inch Sample Size: 6 x 3 x 0.02 inch

17. Tensile Test

18. Tensile Test • Sample 1 show more elongation, more resilient and higher dead load (17.8%) than sample 2, that means more flexible, softer and stronger • Sample 2 (old) is rigid and brittle. • The reason for this might be the damage of fiber structure while the garment had been exposed to fire event. • High temperature, heavy gas and foreign particles deposited onto the garment surface may cause the deformation or decomposition of the fiber

19. TGA • Thermo-gravimetric Analysis (TGA) is a type of testing that is performed on samples to determine changes in weight in relation to change in temperature. • A derivative weight loss curve can be used to tell the point at which weight loss is most apparent TA Instruments TGA 2050

20. TGA *Sample 1: new garment fabric Sample 3: fabric coupon exposed 18hr+ Sample 2: fabric from retired garment

21. TGA The first stage of weight loss might due to fiber moisture or oil containments The second stage of weight loss might be caused by decomposition of additives such as dye, pigment or other smaller molecular polymer mixtures. The third stage which is the main weight loss is due to the burning of fiber itself. Sample 3 has remaining (5.8%), that could be inorganic or metal substances that absorbed by fiber during fire events Different weight loss % in different stage revealed change of fiber structures

22. IGA Interstitial Gas Analysis (IGA) is a technique appropriate for bulk analysis of H, C, N, O and S, by detecting CO (for C) , SO2 (for S), infrared (O as in CO by NDIR) or thermal conductivity (N and H by TCD) while heating up the Sample. Done at EAGSM.

23. IGA (Outer Shell layer ) • Concentration of sulfurin Sample 2 was 65 times than Sample 1, 33 times than Sample 3, while other concentrations of elements were almost the same • This revealed that sulfur was gradually accumulated on the surface or absorbed by cloth fibers

24. IGA (Different Layers) The outer shell layer absorb most sulfur on surface; the concentrations of sulfur on internal layers are most zero

25. XRF • X-ray Fluorescence (XRF) is the emission of characteristic "secondary" X-rays that has been excited by bombarding with high-energy X-rays or gamma rays. • The main purpose of XRF test to analyzed chlorine concentration. The X-ray beam was rastered over an area to obtain a representative sample. Two locations were measured on the sample. • Quantification of Chlorine was performed by calibrating against a PVC sample with a known Cl concentration.

26. XRF (Outer Shell Layer) *Sample 1: new garment fabric Sample 3: fabric coupon exposed 18hr+ Sample 2: fabric from retired garment

27. XRF (Different Layers) The outer shell layer absorb most toxic elements on surface; the concentrations on internal layers are most zero

28. XRF • It revealed that Sulfur and Chloride accumulated into the fiber sample • Other inorganic elements, such as K, Ca, Ti and etc. were also found. These might come from inorganic materials and paintings on wall during fire event • Possible explanation that old fabric (sample 2) had considerable high weight remaining percentage in TGA test. • The outer shell layer absorb most toxic elements on surface; the concentrations on internal layers are most zero

29. Conclusions The conducted analysis showed that the exposed garment contains a lot of harmful chemical species absorbed into the fabric. The exposed fabric reveals decreased mechanical strength and wear. EDS, IGA and XRF results revealed that the concentration of sulfur, nitrogen, chloride elements which represent possible toxic containments are much high in used garment fiber. Other inorganic elements such as K, Ca, Ti were also founded, confirmed by TGA when there is 5.8% remaining at 900oC. The outer shell layer absorb most toxic elements on surface; the concentrations on internal layers are showing an exponential decay

30. Future Work • The goal is to develop approach for evaluation of the protective garment for firefighters which will be able to predict when the garment should be retired • The ultimate goal is to develop a multi-functional sensor incorporated into the garment that will be able to measure body temperature, concentration of the penetrating gas species, moisture level, heart rate, etc.

31. Acknowledgement This research study was supported by the National Institute of Occupational Safety and Health and the Health Pilot Research Project Training Program of the University of Cincinnati Education and Research Center Grant #T42/OH008432-04. The authors thank Prof. Amit Bhattacharya for the valuable scientific discussion related to the proposed research.

32. References Alarie, Y. (2002). "Toxicity of Fire Smokes." Critical Reviews in Toxicology 32(4): 259-289. Mahall, K. (2003). Quality Assessment of Textiles. New York, Springer-Verlag Berlin Heidelberg. Meyer, E. (2004). Chemistry of Hazardous Materials. Upper Saddle River, Pearon Education, Inc. Raheel, M. (1995). Modern Textile Characterization Methods. New York, Marcel Dekker, Inc. V.S. Ramachandran, R. M. P., James J. Beaudoin, Ana H. Delgado (2002). Handbook of Thermal Analysis of Construction Materials. Norwich, Noyes Publications.

33. Q & A