A Comparative Analysis of Glove Permeation Resistance to Paint Stripping Formulations

1. A Comparative Analysis of Glove Permeation Resistance to Paint Stripping Formulations Jeffrey O. Stull, International Personnel Protection, Inc. Richard W. Thomas, TRI/Austin, Inc. Lawrence E. James, BASF Corporation

2. Scope • a multiphase study was undertaken to evaluate how several types of gloves resist multi-chemical based paint stripping formulations

3. Background • Paint stripping involves prolonged, continuous contact with chemical solvent mixtures • Conventional paint strippers include: • methylene chloride, methanol, isopropanol, acetone and toluene • New strippers include less volatile chemicals: • N-methylpyrrolidone, d-limonene, -butyrolactone, and dibasic esters

4. Background • Relatively little information is available to guide the end user in selecting the gloves against paint strippers • Basing glove selection on individual mixture components does not account for possible synergistic mixture permeation

5. Approach • 20 different glove styles evaluated • 7 different surrogate formulations created • 4 different phases • Phase I: degradation screening • Phase II: continuous contact permeation testing • Phase III: intermittent contact permeation testing • Phase IV: permeation testing against selected actual paint stripping formulations

6. Surrogate Paint Strippers

7. Surrogate Paint Strippers

8. Commercial Paint Strippers

9. Glove Selection Criteria • Variety of different glove polymers • Butyl rubber – Nitrile rubber • Natural rubber – PVC • Neoprene – Polymer combinations • Permeation resistance against paint stripping formulation chemicals • Unsupported gloves only • Some gloves available to consumers

10. Glove Selection

11. Degradation Testing • Industry practice (no standard available) • One sided contact • 4-hour exposure • Measurement of weight/thickness changes • Visual observation ratings (swelling, discoloration, curling, delamination, and deterioration) • “0” - no effect • “1” - mild or moderate effect • “2” - severe effect

12. Permeation Testing • Standard Test Method • ASTM F 739 (continuous contact) • ASTM F 1383 (intermittent contact) • Test Parameters • 4-hour duration • room temperature (25 + 2oC) • splash collection method • GC/FID for formulations I - III • GC/MS for formulations IV - VII

13. Permeation Rate Time Permeation Testing • Intermittent contact approach • 5 minutes chemical exposure • 10 minutes purge • Test measurements • Breakthrough time (normalized) • Permeation rate • Determined for each mixture component

14. Overall Results Degradation screening • 7 glove styles show best degradation resistance • Continuous permeation testing shows longer BTs for plastic laminate and butyl gloves • No improvement for intermittent permeation testing • Permeation of gloves by commercial strippers consistent with surrogate strippers Continuous permeation testing Intermittent permeation testing Testing against commercial paint strippers

15. Degradation Criteria • Acceptance criteria • Weight change < 25% • Thickness change < 25% • Overall rating < 3 • No penetration of test specimens

16. Degradation Weight Change

17. Degradation Test Results • Gloves failing against one formulation • Glove E (4H glove); Glove J (North Butyl B-161), Glove P (Comasec Butyl Plus) • Gloves failing against two formulations • Glove S (Guardian Butyl-standard) • Gloves failing against four formulations • Glove G (Pioneer Strip&Stain), Glove H (Pioneer Neoprene NS 401), Glove K (Thompson & Formby Refinishing gloves)

18. Permeation Test Results Lowest Breakthrough Time (minutes) E - Safety 4; P - Comasec Butyl Plus; S - Guardian Butyl K - North Butyl B-161, K - Thompson & Formby Refinishing

19. Comparison of Permeation

20. Actual Paint Stripper Results Lowest Breakthrough Times (minutes)

21. Conclusions • Multi-stage testing program useful for determining permeation resistance • Glove permeation resistance did not always improve with decreasing exposure • Surrogate paint strippers do not always emulate actual stripper permeation • Paint strippers with volatile solvent permeate quicker than those containing NMP or dibasic esters

22. Acknowledgement This work was supported by a grant from the N-Methylpyrrolidone Producers Group, Inc., Washington, D.C.