Step 1.5 Identifying Comparison Values
Advanced Exercise
In air and soil samples taken at the Oak Estates site, assessors found the chemicals listed in the following table. Maximum concentration levels are noted.
Identify the chemicals that need further evaluation. Click on Chemicals and the evaluations needed” for feedback.
Ambient Air |
Air Comparison Value (µg/m3) |
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Chemical |
Maximum Concentration |
Chronic EMEG |
CREG |
Intermediate |
Acute |
Acetone |
13,700 |
30,000 |
na |
30,000 |
60,000 |
Methylene Chloride |
112 |
1,000 |
3 |
1,000 |
2,000 |
1,1,2- Trichloroethane |
31.2 |
na |
0.06 |
na
|
na
|
|
Surface Soil Concentration (ppm) |
Soil Camparison Value (ppm) |
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Chemical |
Maximum Concentration |
Child EMEG |
Adult EMEG |
CREG |
Aroclor 1254 |
14 |
1 |
10 |
na |
Arsenic |
11 |
20 |
200 |
0.5 |
Methylene Chloride |
3.5 |
3,000 |
40,000 |
90 |
na = not available
ppm = parts per millions
µg/m3 = micrograms per cubic meter
Chemicals and the evaluations needed
Acetone
No further evaluation necessary
Because the maximum acetone level is below all of the comparison values in the table, no further evaluation is necessary.
Note: There is no CREG for acetone, but no further evaluation is needed because acetone has not been associated with cancer in humans.
Methylene Chloride
Further evaluation necessary
Because methylene chloride was found at levels above the comparison value.
1,1,2- Trichloroethane
Further evaluation necessary
Because the maximum concentration of 1,1,2-trichloroethane is above the comparison value.
Aroclor 1254
Further evaluation necessary
Because the maximum concentration of Aroclor 1254 is above the comparison value.
Arsenic
Further evaluation necessary
Because levels of arsenic in soil exceed the CREG.
Methylene Chloride
No further evaluation necessary
Because the maximum concentration value is below all of the comparison values presented in the table.
- Page last reviewed: May 31, 2016
- Page last updated: May 31, 2016
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