Document kDrQ3VLq4Zqgao0RKMYdzQx10
FILE NAME: Talc (TALC)
DATE: 0000
DOC#: TALC047
DOCUMENT DESCRIPTION: Book Excerpt - Asbestosform Impurities in Commercial Talcum Powders
PTERONITES AMERICANA';'"
-
: * ;
of the shale unic produced^-'
relationship to the enclosing^--,
am inations.
R eferences
500, C-rSoniferous iavertebrato-fcKv
jrvey, v. 6, pc. 2, 137 p.
-30W
13J l, The Pennsylvanian
ne in Pennsylvania: Pa. Geol. Sufi^K . 36 p.
3S3, Estimation of the com pac-'^
naie from distorted brachiopod
ed. Peis, V. 33, p. 796-738.
;
I860, Carbonio rmacioa und Dy '? Rais, deutsche Akad. Nacurfor-
. Nova Acta Leopoldina, Dresden,
91 f. Fauna of che Wesvoka Forahoma: U.S. Geol. Survey BulL
1337, A sketch of che geological kiny County, accompanying an aiojue of Carboniferous fossils .dge. Ohio: Denison Univ. Sci.
p. 3-70.
*2, Remarks on che Pinnidae: H ' ''rora, v. 23, p. 33 5-346. Form, function, and
Treatsa^ on Invertebrate PaieonMoore, ed.). U nir. Kansas Press, 129-203. 395 (date of im print, 1394), ; Missouri: r . 3, pe. 2, 264 p. 2, The fossils of che Conemaugh Ohio (m D. D. Condi:) : Ohio ulL 17, p. 261-326. 57, Remarks on P rof. Geinitz'i ; che upper Paleozoic rocks and '.eastern Nebraska: Amer. Joar. p. 170-13?, 232-283, 327-339. .eport on che paleontology of <a srich some remarks on the
ocks of chat district (m F. B. 42d Cong., 1st ess.. House
a. 33-23 9. report on some o f the invertethe 27averiy Group and Coal io: Ohio GcoL Survey, v, 2, pc
1-, 1922, Poetsville fauna of
.1. Survey BulL 23, 312 p.
31, The Pennsylvanian fauna of
7 . R. Jlison) : Ky. GeoL Sur-
293-343.
aid G. C. Swallow, 1333, D*-
re fossils from the Coal Met- -
ri and Kansas: Sc. Louis Acad. -
:. p. 193-227.
2-
' 970, Relation of shell form : 'T-
:he Bivalvia (Moilusca) : Ged- ~
an. I?<. 294 p.
"
l
Description of fossil
jec.. .arvey, v. 5, p. 49-154,
i
ASBESTOSFORM IMPURITIES IN COMMERCIAL TALCUM POWDERS
^ David 27. Snider, Dan E. Pfeiffer and Joseph J. Mancuso Department of Geology, Bowling Green State Univerzity, Bowling Green, Ohio
4340 5
A bstract
Eighteen commercial talcum powders were examined by X-ray diffraction and the petrographic microscope to determine the amount and type of asbestosform mineral impurities which were fibrous serpentine, tremolite, actinolite, and anthophyllite and which varied in amount from 4 percent to 46 percent.
P u r po se a n d Sco pe
As part of a major study undertaken tc - :amine the possible relationship of ascutosrorm mineral impurities in talcum powders to incidences of cancer in gerbils (I. I. Oster, 1971, personal com munication), various commercial talcum powders were examined for che type and amount of impurities contained. An initial study by Merliss (1971) implied chat calc-coated rice gave rise to stomach cancer, citing che asbestosform impurities oe " - - a s =he carcinogen. According to Se. ''.jit, Churg, and Hammond (1964), wsescos is a proven carcinogen responsible tor both pulmonary and gastro-incestinal cancer- Eighteen samples of commercial
talcum powders, used as baby powders, shave talcum powders, and spray talcum powders, in a wide price range were ex amined. Labels on che commercial con tainers did not indicate either the pres ence or che percentage of impurities of the commercial powders.
Methods of Study
The qualitative mineralogy of the sam ples was determined by X-ray analysis utilizing a Phillips Model lZOdJ, 60 cycle X-ray diffractometer. Quantitative de terminations of the various minerals and their textural characteristics were made with a Leitz Dialux-Pol petrographic microscope. Percentages listed in Table II were computed by using a mechanical stage and a millimeter point count total ing fifty millimeters.
R esults
The results of the X-ray and micro scopic analyses are presented in Tables I and E.
Table I lists the various minerals which
Tabus L Qualitative Miflera! Analyses by X-ray Diffraction
Sample Number
Aibeitoiiorm Minerals
Anhy Cay
Talc
(Serp. Trem-Act. Aath.) Carbonata drite (Mica)
I
X
X -
X
X
X
X
X
X
X
a XX XX X X X XX XX
S
X
X
X
X
X
s
X
X
X
X
X
X
?
X
X
X
X
1
X
X
X
X
X
X
X
9
X
X
X
10
X
X
X
X
11
X
X
X
X
X
12
X
X
X
X
13
X
X
X
X
X
u
X
X
X
X
X
IT
X
X
X
X
X
6
X
X
X
X
X
13
X
X
X
X
X
X
X
' Additive, ;n d i,n ert m inerals and compounds.
Mire. Mini.*
X X X X X X X X X X X X X X X X X X
65 G O O l
Figure 3
Figure 4
cure 1.--Photomicrograph of sample 1 showing the distribution or talc flakes varying in width from
0.05mm to 0.20mm. The edges
of the individual flakes that are birfringent (white) should not be confused with asbestosfonn
minerals. Crossed Niois.
'igure 2.--Photomicrograph of talc riitf*
found in sample 2 showing bir fringent edges. Slightly Crossed
Niois.
. -
'igure 3.--Photomicrograph of sample
showing distribution of asbestos-
form minerals in a taIc-musT vite matrix. Sligbdy Crossed
Niois.
t _
I 8
figure 4.--Photomicrograph of sample ^
showing asbestosfonn tremolite-
Crossed Niois.
figure 5.--Photomicrograph of sam -
showing distribution of
(
ate mmerals. Uncrossed Nic^i*
occur in the eighteen sarrv % merclal talcum powders. Ir talc (Figures 1 and 2), all i: tain isbestosform miners - which are defined as fibrei tremolite-actinolite, and/or ' (Figures 3 and 4). Carboni
' eous minerals were also den samples (Figure S ). Table II summarizes the of minerals found in the p varies from 4S percent in 92 percent in samples 2 and form impurities range from samples 10 and 12 to 4o pe pie 13. Carbonate, micacect laneous minerals range fro: percent) in samples 2, 3, 1 to 20 percent in samples -
D iscussion
Substantial amounts of mineral impurities occur : eighteen commercial talcur vestigated, although the Ir impurities. Tremolite-actb normal im purity found ir from metamorphosed mage ate rocks while serpentin phyllite are common acre
T a ji_e IL Quantitative
Sample Number
1
2
3
fk
4
5
6
7
I 10
11
12
13
14
li
li
17 15
than l porcene. 'Includes muscovite.
GO 0 2
Figure 4
micrograph of sample 1
-vmg the distribution of talc
<es varying in width from
5mm to 0.20mm. The edges
the individual flakes that are
efnngent (white) should not
confused with asbestosform
nerals. Crossed Nicola,
otomicrograph of talc flake
.nd in sample 2 showing bire-
izent edges. Slightly Crossed
oois.
'
otomicrograph of sample 3
wing distribution of asbestos- .
m minerals in a talc-musco-
matrix. Slightlv Crossed
cols.
ocomicrograph of sample 8
owing asbestosform tremolite.
ossed NicoIs.
micrograph of sample 4
wing distribution of carbon-
mmerais. Uncrossed Nirols- '
o<.-.-or in the eighceen samples of com et*.- ual talcum powders. In addition to cai- (Figures 1 and 2), all samples con tain asbescosform mineral impurities which are defined as fibrous serpentine, cremolice-actinolite, and/or anthophyllite (Figures 3 and 4). Carbonate and micac eous minerals were also detected in most samples (Figure J).
Table II summarizes the percentages or minerals found in the powders. Talc varies from 48 percent in sample 13 to 92 rercent in samples 2 and 10. Asbestosform impurities range from 4 percent in samples 10 and 12 to 45 percent in sam ple 13. Carbonate, micaceous and miscel laneous minerals range from a trace (1 percent) in samples 2, 3, II, 15, and 13 to 20 percent in samples 4 and 12.
D iscussion
'.bstantial amounts of asbestosform .t. .mi impurities occur in each of the eighteen commercial talcum powders in vestigated, although the labels listed no impurities. Tremolite-actinolite is the normal impurity found in calc derived from metamorphosed magnesium carbon ate rocks while serpentine and antho phyllite are common accessory minerals
in calc produced from altered ulcrabasic rocks (Cooper and Hartwell, 1970). However, the labels of the commercial samples did noc designate the source of the raw calc. A wide retail price range was represented by the eighteen samples investigated, but the percentage of asbescosform impurities was noc found co be related to price.
A cknowledgments
The writers wish co thank Dr. I. I. Oster and Miss Karen Gran for supplying the samples of commercial talcum pow ders, and co acknowledge Drs. Lester Valters and Charles F. Kahle for their assistance in the interpretation of the X-ray data.
References
Coop e i , J. D., and J. W. Hast-v e ix , 1970, Talc, soapstone, and pyrophyilice: Mineral Facts and Problems, 1970 Edition, U. S. Bureau o Mines BulL SS0, p. 1247-1231.
Mzauss, R. R.. 1971, Taic-created rice and Jap anese stomach cancer: Science, v. 171, no. 4002, p. 1141-1142.
SELntorr, J., J. O n m e, and E. H ammond, 1944 Asbestos exposure and neoplasia: Jour. Amer. Med. Assoc., v. 1SS, p. 22-Z4.
T a i l s H. Quantitative Mineral Analyses try Petrographic Microscope (Volume Percent)
Sample Number
1 2 3 4 i s 7 S 9 10 11 12 13 14 11 14 17 IS
` Lese than 1 percent, eluder muscovite.
Percent Talc Flakee
73 9Z *79 S7 S2 72 S 9 41 SO 92 8 4 74 4S 90 74 SO 70 74
Percent Carbonate
fti-iim
S 'cracc enee
20 trace to 1
13 I 5 4 4 .
enee 20
4 4 4 enee 4 enee
Percent Asbestoarorm
Minerals
22 s
21 23 IS li
4 34 14
4 14 4 44
4 22 20 24 24