A miniature sampler for in-mask workplace measurements: First pilot tests and site visit experiences

Transcription

1 Health and Safety Executive A miniature sampler for in-mask workplace measurements: First pilot tests and site visit experiences Peter Stacey, Rhiannon Mogridge, and Alison Bowry peter.stacey@hsl.gsi.gov.uk

2 Exposure by Mass Concentration Measurement

3 The miniature respirable particulate sampler

4 The miniature respirable particulate sampler

5 Capability Approved for use with selection of FFP 3 masks Samples respirable fraction 4 h in 94 % humidity Performance comparable with the SIMPEDS cyclone Tested on volunteers in laboratory (NaCl aerosol) Does not affect protection factor significantly Peter Stacey, Andrew Thorpe, Rhiannon Mogridge, Taekhee Lee, Martin Harper; A New Miniature Respirable Sampler for In-mask Sampling: Part 1 Particle Size Selection Performance. Ann Occup Hyg 2016; 60 (9): Rhiannon Mogridge, Peter Stacey, James Forder; A New Miniature Respirable Sampler for In-mask Sampling: Part 2 Tests Performed Inside the Mask. Ann Occup Hyg 2016; 60 (9):

6 How is the sampler fitted?

7 Field Tests Purpose To assess the miniature sampler s practical use at the workplace

8 Field Tests Three (3) sites visited Seven (7) workers and one (1) researcher Ethics Protocol Volunteers Health questionnaire Chief HSE medical officer approval Fit tested on site with HSE supplied FFP3 masks Monitored through sampling

9 Field test Our Experience Site 1 Inward leakage for iron = 1-24 %

10 Field Tests Our Experience- Site 2

11 Field Tests Our Experience Site 3

12 Field test The Volunteer Experience Comfortable No complaints Can you feel it? one person = occasionally One person = tubing got caught when writing Three people = pumps positioning (preferred the side)

13 Field Test Our Experience Generally Sampling times = 1 2 h Tubing came off one pump reattached quickly Two people = moisture noted in post sampler tube to pump

14 Laboratory Tests Mass and Number Concentration Photo credit GRIMM Miniature sampler Respirable Mass < 16 µm 50 % penetration = 4 µm Mini WRAS Mass and number concentration µm Photo credit Portacount TSI Inc PortaCount Number concentration only About 1 µm and less

15 Simulated work tasks

16 Comparison of mini sampler with MiniWRAS in-mask concentration 3500 Gravimetric mass Vs mass from particle size using density Mini sampler dust concentration (ug/m 3 ) MS1 MS MiniWRAS Alveolic dust concentration (ug/m 3 )

17 Aerosol size distribution Concentration (paeticles/cc) Challenge In-mask Particle size (nm)

18 Leakage by particle size Inward leakage (%) Particle size (nm)

19 Messages Initial workplace trials = success Identified practical issues Miniature sampler opportunity to compare mass and number concentration values Some proportion of inward leakage across all sizes up to 35 µm (face seal leakage) Larger sizes = more mass

20 HSL is the commercial arm of the Health and Safety Executive, HSE. Our commercial work delivers high quality science to meet the needs of industry and government in the UK and overseas. Our commercial customers can commission services and research using our state-of-theart scientific laboratory in Buxton, as well as analytical expertise from other parts of HSE s science base.