OSHA Lowers Limit for Crystalline Silica to 50mg/m3

OSHA lowers limit for crystalline silica to 50ug/m3

READ: How the CIP 10 can lower the LOD, in determining Crystalline silica:

…. the following is a lengthy discussion , but if you have concerns about STEL situations, read on:-

Preamble

The new rule has been published. It calls for sample collection according to the ISO respirable convention, but recognizes that the Dorr-Oliver cyclone at 1.7 Lpm has been meeting that specification all along.

So it continues to allow the Dorr-Oliver to be used for compliance with the new, lower PEL (50 ug/m3) and action level (25 ug/mm3), but notes that the DO has a harder time collecting sufficient sample to analyze below the action level or for short-term samples below the PEL.
In addition, any samples complying with the PEL using the DO cyclone will be outside the range of PT samples currently being issued by the AIHA PAT program. Thus size-selective samplers that comply with the ISO convention at higher flow-rates are allowed to demonstrate compliance under the rule. (the CIP 10R is mentioned in the OSHA document as an alternative)

Quick synopsis of CIP 10R specifications. Full CIP 10 info

The CIP 10 samples at 10 LPM . and samples the respirable fraction ( aka Alveolar) with its internal particle size selector.

The unit weighs only 11 oz and runs for 16 hours on a single 24 hr charge.

It has no external cyclones or tubing to get snagged. It is also very easy to calibrate in the field (see the video on our website under “Videos and PPT” tab) It is also extremely quite (51 db)

The CIP 10 has been the standard method for sampling crystalline silica France and is both an AFNOR and ISO standard.

ISO 16258, part 1, part 2. September 15th 2015. Includes a filter method in Part 1 and the CIP 10 with the foam method .The foam analysis is in part 2.

National Standard , 1995 France NF X43-295 (Still in force)

Determination of Respirable Crystalline Silica By X-Ray diffraction (in French) using the CIP 10

Adoption of the above methods requires, that a laboratory self-validates the method. Information on how to do this can be found in the following article,

Validation of the analysis of respirable crystalline Silica (Quartz) in Foams used with CIP 10R Samplers.
Celine Eypert-Blaison, Jean Claude Moulut, Thierry Lecaque ,Florian Marc, Edmond Kauffer Ann Occup. Hyg. Vol 55 No 4 pp 257-68 2011

Additional references of interest

Producing Samples for the Organization of Proficiency Tests. Study of the Homogeneity of Replicas Produced From Two Atmosphere Generation Systems , 2010
LAURENCE FREVILLE*, JEAN-CLAUDE MOULUT, MICHEL GRZEBYK and EDMOND KAUFFER Ann Occup Hyg Vol 54, No 6 pp 659-670 2010

Collection Efficiencies of High Flow Rate Personal Respirable Samplers When Measuring Arizona Road Dust and Analysis of Quartz by X-ray Diffraction
Peter Stacey, Taekhee Lee, Andrew Thorpe, Paul Roberts, Gillian Frost and Martin Harper. Ann Occup Hyg Vol 58 No 4 pp 512-523 2014

Performance of High Flow Rate Samplers for Respirable Particle Collection
TAEKHEE LEE, SEUNG WON KIM, WILLIAM P. CHISHOLM, JAMES SLAVEN and MARTIN HARPER. Ann Occup Hyg Vol 54 No 6 pp 697-709 2010

Quartz Measurement in Coal Dust with High-Flow Rate Samplers: Laboratory Study
TAEKHEE LEE, EUN GYUNG LEE, SEUNG WON KIM,WILLIAM P. CHISHOLM, MICHAEL KASHON and MARTIN HARPER Ann Occup Hyg Vol 56 No 4 pp 413-425 2012

Silica Measurement with High Flow Rate Respirable Size Selective Samplers :A Field Study
Taekhee Lee, Martin Harper, Michael Kashon, Larry A. Lee, Catherine B. Healy, Marie A. Coggins, Pam Susi and Andrew O’Brien Ann Occup Hyg 1-14 2015