A Series of Negative Exposure Assessments Related to Asbestos Containing Components Still Used in Railroad Equipment Today

Transcription

1 A Series of Negative Exposure Assessments Related to Asbestos Containing Components Still Used in Railroad Equipment Today - PO108 - American Industrial Hygiene Association s 66th Annual Conference and Exposition May , Chicago, Illinois F.W. Boelter, CIH, PE M.T. Weeks, CIH C.E. Simmons, CIH Boelter & Yates, Inc. Park Ridge, IL

2 Negative Exposure Assessment 29 C.F.R (f)(2)(iii) Objective data product or material or activity cannot exceed TWA and EL (8hr TWA 0.1f/cc, 30min EL 1f/cc) work conditions having the greatest potential Data collected during work operations closely resembling employer's current operations processes type of material control methods work practices environmental conditions Employee training and experience < current employees Certainty employee exposures < TWA and EL TWA 0.1f/cc, EL 1f/cc

3 Assessment Strategy Field observation Interview individuals Observe work practices Select representative activities Evaluate exposures Use validated protocols If conducting a chamber study activities must representative of sequence time and motion Data must be relevant, reproducible, and predictive.

4 Products, Materials, Activities Basic Characterization Suspect materials Interested in components of equipment Building materials already inventoried Bulk analysis When encountered By whom Doing what

5 Inventory of Findings Materials List of suspects was long List of positive components was short Visual identifiers were subtle to indistinguishable All components were non-friable or encapsulated products Anticipated fiber release potential was low

6 NEA Candidates Bakelite Relay rack terminal strips Transformer terminal strips Arc chutes Miscellaneous Arc pads Wire & cable Aerial cable Motor starter board wiring Friction Outboard brakes Switch machine clutches

7 SEGs & NEAs Bakelite Task specific With other activities Friction Field service Shop rebuild Motor Boards Field installed Shop rebuild Cable Outdoors Indoors

8 Term used generically Bakelite Anything that looks like a molded product Negative Materials Plastic or quasi-plastic looking brown or black Cut, sawn or snapped Positive Materials % chrysotile by PLM Not actually Bakelite Simply handled Never cut, sawn or snapped

9 Bakelite

10 Bakelite

11 Bakelite NEA

12 Bakelite NEA Full-Shift Personal Samples Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT NIOSH 7400 PCM (Total f/cc) 8-Hour TWA Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 8-Hour TWA Personal Samples < < < Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT Excursion Limit (aka STEL) Personal Samples NIOSH 7400 PCM (Total f/cc) 30-Minute Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 30-Minute Personal Samples 0 20

13 Friction Materials Generally holds something in place Brake shoes on motor drum Solenoid released Often never replaced over life of machine Field adjusted Possibly replaced but not relined ND-65% chrysotile by PLM Clutch w/ fiber discs Always engaged Slips to protect machine Maybe field replaced but never field serviced Open and close controller w/ arc pad (pad never replaced) Shop rebuilt occasionally ND-80% chrysotile by PLM

14 Friction Materials

15 Friction Materials NEA 1

16 Friction Materials NEA 1 Full-Shift Personal Samples Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT NIOSH 7400 PCM (total f/cc) 8-Hour TWA Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 8-Hour TWA Personal Samples < < < < Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT Excursion Limit (aka STEL) Personal Samples NIOSH 7400 PCM (total f/cc) 30-Minute Personal Samples < NIOSH 7402 TEM (Asbestos f/cc) 30-Minute Personal Samples

17 Friction Materials NEA 2

18 Friction Materials NEA 2 Full-Shift Personal Samples Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT NIOSH 7400 PCM (total f/cc) 8-Hour TWA Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 8-Hour TWA Personal Samples < Excursion Limit (aka STEL) Personal Samples Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT NIOSH 7400 PCM (total f/cc) 30-Minute Personal Samples < NIOSH 7402 TEM (Asbestos f/cc) 30-Minute Personal Samples

19 Motor Control Board Materials In-Field, replace entire panel In Shop, scavenged for parts Handle backing board 75% chrysotile by PLM Replace wiring Insulation 35-55% 55% chrysotile by PLM Handle arc chutes ND-50% chrysotile by PLM

20 Motor Control Board Materials

21 Motor Control Board Materials Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT Full-Shift Personal Samples NIOSH 7400 PCM (Total f/cc) 8-Hour TWA Personal Samples Excursion Limit (aka STEL) Personal Samples NIOSH 7400 PCM (Total f/cc) 30-Minute Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 8-Hour TWA Personal Samples < < < NIOSH 7402 TEM (Asbestos f/cc) 30-Minute Personal Samples 0 14

22 Cable Materials Aerial Cable Woven cloth Manipulate, cut, strip No visual differences between positive and negative Multiple layers ND-70% chrysotile by PLM Work is done indoors and out of doors Unventilated bungalows

23 Cable Materials

24 Cable Materials Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT Excursion Limit (aka STEL) Personal Samples Cloth-Woven Cable Cutting and Stripping - Outdoors NIOSH 7400 PCM (Total f/cc) 30-Minute Personal Samples 0 5 Asbestos f/cc 30-Minute Personal Samples* 0 5 Statistical Function MAXIMUM MINIMUM MEAN S.D. COUNT Excursion Limit (aka STEL) Personal Samples Cloth-Woven Cable Cutting and Stripping Inside NIOSH 7400 PCM (Total f/cc) 30-Minute Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 30- Minute Personal Samples

25 Conclusions Variety of asbestos containing, non-friable, encapsulated, non-building material components still used or encountered in railroad operations Often asbestos containing and non-asbestos containing components are indistinguishable None of the activities performed with these components results in significant exposures High degree of confidence exceedance of OSHA PEL (TWA 0.1f/cc, EL 1f/cc) will not occur

26 A Series of Negative Exposure Assessments Related to Asbestos Containing Components Still Used in Railroad Equipment Today Fred W. Boelter, CIH, PE Boelter & Yates, Inc. Park Ridge, Illinois 847/