Instructions for Statistical Calculations Spreadsheets |
NOTE: Use of these spreadsheets presumes that the user has obtained a copy of ASTM D7886 Practice for Asbestos Exposure Assessments for Repetitive Maintenance and Installation Tasks from ASTM International at www.astm.org. These spreadsheets are not part of the downloaded file for ASTM D7886, are not an ASTM product and are not copyrighted by ASTM. Neither ASTM International, The Environmental Consultancy or Andrew F. Oberta, MPH, CIH are responsible for any circumstances arising from the use of the spreadsheets. |
BEFORE YOU START Review ASTM D7886 with special attention to Section 7. Exposure Calculations. CLICK HERE to open the file D7886samplecalculations.xls, make a working copy and save the original unchanged. |
WHAT THE SPREADSHEETS DO They calculate the exposures for each test, including the TWA (90 or 120 minute) and EL (30 minute) tests. They calculate the 8-hr TWA exposure and the 95% UCL of the set of TWA tests, and the average and 95% UCL of the set of EL tests. (In ASTM D7886 the Confidence Factor (CF) is equal to the 95% UCL.) The spreadsheets are set up for calculating fiber concentrations from samples analyzed by NIOSH Method 7400. They are not set up for calculations based on analysis by NIOSH Method 7402, which is an option in ASTM D7886. |
USING THE SPREADSHEETS NOTE: You can insert one or more columns before Column A or between Columns A and B to add information such as worker identification or description of the test conditions. Do not insert or delete rows in the table. |
Sample Number column |
Sampling time, min column The default values of 90, 120 and 30 are entered in this column. When taking the samples, it is important to adhere to these times as closely as possible. If you deviate slightly from these times, enter the actual sampling times in place of the default values. The No Monitoring time is automatically calculated by the program. |
Flow rate, min column |
Volume, liters column The volume for each sample will be calculated by the program. |
Fibers counted column |
Fields counted column The default value of 100 has been entered. If less than 100 fields are counted, replace 100 with the actual number. |
Fibers/cc column |
TWA Calculations columns The TWA concentrations and No Monitoring values are copied automatically from the Fibers/cc column. The 8-hr TWA, Average TWA and 95% UCL (CF) concentrations are calculated by the program using the equations in Section 7 of ASTM D7886. |
EL Calculations columns |
TO OPEN THE FILE D7886samplecalculations.xls CLICK HERE |
Return to Exposure Assessments page |