Document J37MB6xQ78oKmKRgyXwwZe946
Corporate Engineering
PLAINTIFF'S EXHIBIT
Western Electric
222 Broadway New York, N.Y 10038 212 571-2345
May 27, 1980
Re: Test for Screening Asbestos
Attached, for your information, is a copy of the test procedure developed by NIOSH for confirming the presence of asbestos in suspect materials.
Att.
Letter to: All Industrial Hygienists
Industrial Hygiene
LLA 001110
TEST FOR SCREENING ASBESTOS
Walter S, Kim
James W. Carter, II
Richard E. Kupel
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service Center for Disease Control National Institute for Occupational Safety and Health Division of Physical Sciences and Engineering
Cincinnati, Ohio 45226
October 1979
LLA 001111
TEST FOR SCREENING ASBESTOS
I. SCOPE AND APPLICATION
This colorimetric test is applicable to the detectlsn of magnesium (II) and iron (II) from asbestos in bulk samples. These samples include sprayed on asbestos as well as ceiling tiles. The test is simple and can be readily used in the field to screen for the presence or absence of asbestos. The amount of the sample needed for the test is only about the size of a large pea.
II. PRINCIPLE
+2 The te| is based upon the formation of <j^lor complexes with Mg and Fe released from asbestos. The Mg ^from chrysetile is complexed with p-nitrophenylazo-a-naphthol. The Fe from crocidolite and amosite is complexed with 1, 10-phenanthroline.^A positive^est is indicated by the formation of colored complex for Mg and/or Pe , and it indicates possible presence of asbestos.
III.
INTERFERENCES
The test is a colorimetric spot test for Mg,+2 and Fe.+- 2. specific for asbestos.
and is not
A bulk sample may contain Mg and Fe compounds other than asbestos^ Without treating the sample as in the Procedure, a fern drops of color forming reagents are added directly to the sample* IT either color forms, an interferring substance is present and the sample must, be cleaned before the test is conducted to eliminate the interference.. In this cleaning process, plaster, mineral wool, fiberglass, and. soluble Mg and Fe compounds are removed before the- screening test, preventing their interference.
IV. SENSITIVITY, PRECISION, AND ACCURACY
A sample containing more than 1Z asbestos gives a positive color reaction.
A total of 198 various field samples were tested before the Acid Wash steps were added to the Iron Test procedure. Results are listed be low:
Results of the screening test without the Acid Wash.
LLft 001112
No. of Samples
Z of Total
True Positive
79
40
False Positive
50
25
True Negative
69
35
False Negative
0
0
With the Acid Wash, the following results were obcained from 13 samples.
Results of the screening test with the Acid Wash.
No. of Samples
Z of Total
True Positive
5
38
False Positive
0
0
True Negative
8
62
False Negative
0
0
V. APPARATUS
1. Teflon dish or white plastic plate 2. Plastic or glass rod 3. Dropping plastic pipet 4. 15 mL disposable plastic beaker 5. 25 mm size 0.8 ym mixed cellulose ester filter
6. ~ 25 mm size polyvinyl chloride filter 7. 25 mm Swinnex filter holder and gasket 8. 10 mL disposable plastic syringe
VI. RSAGENTS (Reagent Grade)
1. Phosphoric acid, concentrated.
2. 10 N sodium hydroxide - Dissolve 40 g of NaOH in 100 mL of water.
3. Mg Reagent - Dissolve 1 mg of p-nitrophenylazo-a-naphthol in 100 mL of 2 N NaOH. Age at least a day. This reagent is stable over a month.'
4. Hydrofluoric acid - Dilute 20 mL of HF with 20 mL of water. Add 0.6 mL of concentrated HC1.
5. Fe Reagent - Dissolve 2 g of 1,10-phenanthroline in 50 mL of ethanol. This reagent is stable over a month: --
6. Glycerin, reagent grade.
7. Acetic acid, concentrated glacial.
8. Sulfuric acid, concentrated.
9. Double de-ionized water.
LLA 001113
VII. PROCEDURE
A. Magnesium Test
1. Add a few drops of Mg Reagent directly to the sample. If blue color appears, wash the sample with glycerin before the test. Any sample containing plaster is also washed with glycerin.
Glycerin Wash
a. Place a small portion of sample, about the size of a large pea, in a plastic beaker.
b. Add 5 drops of glycerin and mix well with a plastic rod or spatula.
c. Rinse the plastic rod with a small amount of water into the beaker.
d. Filter the sample through the filtration assembly consist ing of a syringe attached to the Svinnex filter bolder loaded with a mixed cellulose estet filter and a gasket.
e. Filter with a minimum of 5 washings or about 50 ml of water.
f. Transfer the filter to a Teflon dish for the Magnesium test.
2. Add a drop of H^PO^ and mix well by grinding the sample with a plastic rod.
3. Add 2 drops of 10 N NaOH and mix well.
4. Add 5 drops of Mg Reagent and stir briefly. Note any color change.
5. Add 5 more drops of Mg Reagent and observe the .final color.
6. A blue color indicates that chrysotile may be present.
7. Samples giving a positive test may be sent -to a laboratory for confirmation. If the magnesium test is-negative, the sample must be tested for iron.
B. Iron Test
1. Add few drops of Fe Reagent directly to the sample. If a red color appears, wash the sample with the acetic--sulfuric acid mixture before the test. Samples containing fiberglass or mineral wool are also washed with the acid mixture.
LLA 001114
Acid Wash
1. Place a small portion of the sample, about the size of a large pea, in a plastic beaker.
2. Add 5 drops of concentrated acetic acid.
3. Add 5 drops of concentrated sulfuric acid.
4. Mix well and ultrasonicate if available for 5 minutes.
5. Filter the sample through a polyvinyl chloride filter with a minimum of S washings or about 50 mL of water.
6. Transfer the filter to a Teflon dish and proceed with the Iron Test.
2. Add a drop of HF solution and mix well.
3. Add 5 drops of Fe Reagent and observe the development of red color.
4. The red color indicates that amosite or crocidolite may be present.
C. Notes
If both parts of the test give negative responses, there is a low probability that any asbestos is present. Once the presence of mag nesium and/or iron is indicated, further analysis, if needed, is done in the laboratory to confirm, identify the type, and quantitate the percentage of asbestos.
VIII. REFERENCE
1. Caution: Asbestos Dust. A scriptographic booklet by Channing L. Bete Co., Inc., Greenfield, Mass. Prepared in cooperation with U.S. DHEW, PHS, CDC, National Institute for Occupational Safety and Realth, Cincinnati, Ohio (1973).
2. Fritz Feigl: Spot Test3 - In Inorganic Analysis. Translated by Ralph E. Oesper. 5th Edition. Elsevier Publishing Company, Amsterdam. (1958) p. 225-227.
3. Walter S. Kim, James W. Carter, II, and Richard E. Kupel: Quick Screening Test for Asbestos. U.S. DHEW, PHS, CDC, NIOSH, Cincinnati, Ohio. To be published in AIHAJ.
LU 001115