STATISTICS ON THREE REGULATED ASBESTIFORM AMPHIBOLES: LENGTH, WIDTH AND ASPECT RATIO B. LI, PhD N.C. BATTA, MS, RPIH S. C. SU, PhD N. K. BATTA, PE BATTA LABORATORIES, INC.

2 SIGNIFICANT PHYSICAL PROPERTY OF ALL AMPHIBOLES: CLEAVAGE

3 AMPHIBOLE CRYSTAL FRAGMENTS BREAK PREFERABLY ALONG CLEAVAGE PLANES BY: Crushing Milling Grinding

4 HOW BIG A ROLE CAN CLEAVAGE PLAY IN DEFINING FIBER DIMENSIONS IN TERMS OF: LENGTH WIDTH ASPECT RATIO

5 AND MOST IMPORTANTLY: SAMPLE PREPARATION FIBER COUNT WEIGHT ESTIMATE

6 EXPERIMENTAL DESIGN MATERIAL NIST STANDARD – ANTHOPHYLLITE AND A MIXTURE OF TREMOLITE AND ACTINOLITE USING THE MIXTURE RATHER THAN EACH OF TREMOLITE AND ACTINOLITE WAS DETERMINED BASED ON THEIR CLOSE SIMILARITY IN PHYSICAL PROPERTY AND STATISTICAL BEHAVIOR OF FIBER DIMENSIONS AT THE BEGINNING OF THIS STUDY

METHOD METHOD: INSTANT PLM PREP AND MANUAL GRINDING WITH TIME INTERVALS OF: 0 (instant prep), 5, 15, 30, 60 AND 120 MINUTES TIME INTERVALS (i.e. 5, 15, … minutes) WERE INTENDED TO APPROXIMATE DIFFERENT SETTINGS OF MACHINE GRINDERS OR PULVERIZERS

MEASUREMENT MEASUREMENT & RECORDING: PLM (0- 15) AND TEM (15-120) FOR LENGTH, WIDTH AND FIBER END SHAPES ALL FRAGMENTS (INCLUDING BUNDLES) WERE NON-SELECTIVELY, BUT SEPARATELY MEASURED REGARDLESS WHETHER THEY ARE IN THE FORMS OF CLUSTERS OR MATRICES (NOT SO COMMON IN THIS PREP DUE TO PURITY).

9 RESULTS

10 AVERAGE LENGTH CHANGE THROUGH TIME PLM TEM

11 AVERAGE WIDTH CHANGE THROUGH TIME PLM TEM

12 ASPECT RATIO DISTRIBUTION OVER TIME - ANTHOPHYLLITE

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18 CHANGE IN AVERAGE ASPECT RATIO THROUGH TIME PLM TEM

19 ASPECT RATIO DISTRIBUTION OVER TIME FOR TREMOLITE AND ACTINOLITE IS SIMILAR TO ANTHOPHYLLITE

20 HOW DOES CHANGE IN FIBER LENGTH AND ASPECT RATIO AFFECT WEIGHT AND COUNTS?

21 FIRST: HOW DO ASPECT RATIOS VARY WITH AMPHIBOLE SPECIES?

22 ANTHOPHYLLITE PLM TEM

23 TREMO-ACTINOLITE PLM TEM

24 SECOND: HOW DO THESE CHANGES AFFECT ASBESTOS COUNTS AND WEIGHT BY ANALYTICAL METHODS?

25 IMPACT ON COUNTS FOR ANTHOPHYLLITE

26 IMPACT ON COUNTS FOR TREMO- ACTINOLITE

27 IMPACT ON WEIGHT/MASS FOR ANTHOPHYLLITE

28 IMPACT ON WEIGHT/MASS FOR TREMO-ACTINOLITE

29 WHO MADE SUCH A “MASS”?

30 CLEAVAGE?

31 CLEAVAGE BEHAVIOR EXHIBITED BY FIBER ENDS SHAPES PLM TEM

32 What Have We Learned So Far?

33 CONCLUSION CLEAVAGE IS AN INTRINSIC PROPERTY OF ALL AMPHIBOLES DIRECTLY OR INDIRECTLY IMPACTING ON LENGTH, CLEAVAGE DICTATES ASPECT RATIO BEHAVIOR DURING SAMPLE PREP METHODS OF PREP CAN HAVE SIGNIFICANT IMPACT ON FIBER COUNTS AND WEIGHT METHOD ACCURACY IS A FUNCTION OF METHODS OF PREPARATION

34 SUGGESTED CORRECTIVE ACTIONS ACKNOWLEDGE THE EXISTENCE OF CLEAVAGE FIBERS. IN ANOTHER WORD, CLEAVAGE FIBERS ARE ASBESTOS FIBERS AS LONG AS THEY MEET THE FIBER DEFINITION VARIOUS PREPARATION METHODS HAVE TO BE EVALUATED QUANTITATIVELY USING AN APPROACH SIMILAR TO THIS STUDY FOR THEIR IMPACT ON COUNTS AND WEIGHT ESTIMATE ANALYTICAL METHODS HAVE TO BE CHOSEN BASED ON PREP METHODS FOR OPTIMAL ACCURACY CLIENTS AND THE PUBLIC HAVE A RIGHT TO KNOW WHAT PREP METHODS WERE CHOSEN AND HOW THEY AFFECT THEIR RESULTS ALTHOUGH IT WAS KNOWN THAT GRINDING OR PULVERIZING WOULD HAVE IMPACT ON FIBER COUNTS OR WEIGHT ESTIMATE, UNCERTAINTY OR A CONVERSION FACTOR HAS TO BE QUANTITATIVELY DETERMINED AND REPORTED WITH THE RESULTS ACCORDING TO THE PREP METHOD ADOPTED

35 THANK YOU ALL! WHAT WE DO AT BATTA LABORATORIES ASBESTOS ANALYSIS (PLM, PCM & TEM) CHEMISTRY (ALL REGULATED METALS) RESEARCH AND DEVELOPMENT INTERNSHIP PROGRAM PUBLIC OUTREACH PROGRAM