Document GKv0d1QJyvzod40p9k7jM5rQ7
AP
STUDY SUMMARY FOR W ORK PERFORMED DURING 1977-1979
TEST SUBSTANCE_____________________________________
Identity: Perfluorooctanesulfonate; may also be referred to as PFOS or FC-95. (1-Octanesulfonicacid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8heptadecafluoro-, potassium salt, CAS # 2795-39-3)
Rem arks field: The test substance is a white powder of uncharacterized purity.
The attached is an overview created in 1979 for studies completed from 1977 to 1979. Robust summaries have already been submitted for many of these studies. Others have not been summarized due to the fact new studies exist that supercede these or they are being repeated.
STUDIES_____________________ ___________________________________
W ater solubility; biodegradation; soil sorption; octanol/water partition coefficient; Static Acute Toxicity to Bluegill Sunfish (Lepomis macrochirusy, Static Acute Toxicity to Rainbow Trout (Salmo gairdnen); Static Acute Toxicity to Fathead Minnow (Pimephales promelas); Static Acute Toxicity to Daphnia magna; Chronic Flow Through Study on Fathead Minnow (Pimephales promelas)
DATA QUALITY__________________________________________________
Reliability: These studies have been assigned Klimisch rankings = 2. They satisfied criteria for quality testing at the time performed, but have some deficiencies. In many cases actual concentrations were not measured. The value was determined by indirect measurement (e.g., solubility) or Using nominal concentrations (e.g., aquatic toxicity). In some cases, the analytical methodology itself was questionable. Additionally, these studies lack sufficient characterization of the test substance purity.
OTHER
Subm itter: 3M Company, Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133
Last changed: 5/3/00
001714
MICHIGAN STATE UNIVERSITY
DEPARTMENT OF CROP AND SOIL SCIENCES PLANT & SOIL SCIENCES BUILDING
May 19, 1993
EAST LANSING MICHIGAN 4M24-1325
Dr. Robert D. Howell 3M Company 3M Center, Bldg. 2-3E-09 St. Paul, MN 55144-1000
Dear Dr. Howell:
Enclosed are my review comments regarding the nine 3M Techniclal Reports, recommendations for Improving the quality of the Individual studies, and some recommendations for future research. Please review this Information and let me know If I can be of any further assistance.
I do have interest in submitting a research proposal to 3M in accordance with the recommendations for future research. Perhaps we could discuss this further. I enthusiastically support your efforts to obtain information on the environmental fate and behavior of the 3M products.
My consulting fee for the work performed to date is $3,200.00 (three and one half days for review of materials and preparation of reports plus one half day consultation with Dr. well at MSU, at $800.00 per day).
Sincerely
/
Professor
MSU it am Affirmmtivt Action/Equal Opportunity uttitution
001715
Review o f Technical Report Summary Final Comprehensive Report FC 95
An octanol-water partition coefficient o f 10 would predict a supercooled liquid solubility o f 250 g/L using the equation:
log K, = -0.862 log Sw + 0.710
Conversely if the water solubility of the solid is 286 mg/L, then the supercooled liquid solubility could be -- 2860 mg/L. Using the above equation, this predicts a K^, value of about 500. The predicted values are quite different than the measured values, and the measured K, and Sw values seem inconsistent, i.e., if the measured Kw is correct, I would expect a higher water solubility, and if the measured solubility is correct I would expect a higher K ,, . The values look suspicious.
FC 95 is described as an anionic surfactant. If so, does it form micelles and exhibit a well defined critical micelle concentration similar to SDS for example. If so, then I 'm not certain talking about water solubilities is appropriate. Rather behavior above and below the CMC should be examined.
Table 2 presents soil sorption data which is virtually meaningless. The percent sorbed is going to vary depending on the experimental variables of amount of soil, type o f soil, volume o f water, concentration o f FC 95. You need to measure the entire soil sorption isotherm and obtain a sorption coefficient. This should be done on several soils. Again, if FC 95 is a conventional micelle forming surfactant I would expect different soil sorption behavior above and below the CMC. I would not expect linear isotherms.
A K value o f 45 is reported based on data from another report (reference 3). To evaluate the appropriateness of this value, it should be obtained on several different soils and be relatively constant, or be consistent with K*. values predicted from empirical relationships such as:
log K*. = 0.904 log Kw - 0.539
(Chiou et al. Environ. S d . Technol. 17:227231)
Using the value of 10, the predicted K, value is about 2 which is much lower than the measured value o f 45. Again, this points to the inconsistencies o f the measured K ^ , Swand values reported. The KM and/or Sw values measured are also being used to predict bioconcentration factors using empirical relationships like the one above. This is a reasonable approach if the or Sw values are accurate. As mentioned above Kw and Sw reported seem to be inconsistent, so I don't have a lot of confidence in using them to predict other things like BCF.
001716
Recommendation 1. Need an accurate determination of water solubility and octanol-water partition coefficient
(See methodology of Chiou and Schmedding, 1980 - given in previous report.) 2. Determine the CMC of FC 95, and recognize that its behavior above and below the
CMC will be different. 3. - Obtain soil sorption isotherms on several soils and calculate K values from these. 4. Check for consistency between Sw, and K*. values.
001717
rorm 6747-tV A
r t>
TECHNICAL REPORT SUMMARY
TO: TECHNICAL COMMUNICATIONS CENTER - 20I-2C N
Oat
3/15/79
(im p o rtan t -- I f rep o rt sp rin ted on both sides o f paper, send tw o copies to TCC J
Division
Environmental Laboratory'(EE & PC)
Project
Fate of Fluorochemicals
Report Title
Final Comprehensive Report: FC 95
To
R. A. Prokop
Y4 ^
A. N. Welter
Notebook Reference
SECURITY ^
D Open
(Company Confidential)
S Closed
(Special Authorization)
3M CHEM ICAL ^ REG ISTRY "
Dept. Number
0535
Protect Number
9970612643
Report Number
Oil
09362
N a of Fag* Including Covertheet
12
New Chemicals Reported
Yes
Qj No
KEYWOROS: (Select terms from 3 M Thesaurus. Suggest other applicable terms.)
CURRENT OBJECTIVE:
Final Report:
Encompasses all work performed during the period 1977 t 1979.
EE&PC - Div. Fluorochemical (analytical) (Aquatic) (Degradation) (Soil) Toxicity
R EP O R T ABSTRACT: (200-250 words) This abstract inform ation is distributed by the Technical Communications Center to alert 3 M `ers to Conytany R &O . It is Company confidential material.
D. L. Bacon R. L. Bohon V. Pothapragada
Information Liaison
Initials:
/j ^
3M CONFIDENTIAL
001718
^ 4?
2
Introduction
The rationale for performing environmental effects^studies on fluorochemicals has been discussed previously^1 .
The subject fluorochemical of this report is FC 95 (an anionic surfactant) which has a potential for widespread distribution in the environment as this material is used by the chrome plating, and etching industries, both domestically and internationally. FC 95 chemically is the potassium salt of perfluorooctane sulfonic acid.
C8 f 17 s o 3k
FC 95
This material is an off-white powder, having a molecular weight of 538 and the chemical structure shown above.
This report consolidates all available information in the areas of aquatic toxicity, soil sorption studies, degradation, water solubility and partition coefficients and defines the probable environmental risk of FC 95.
Methods
Water solubility, biodegradation and soil sorption studies have been the subject of technical reports11" . These specific experimental methodologys have been defined in these reports and should be consulted for specific details.
A) Aquatic Testing
The testing protocols utilized for this study.were modeled after that described by USEPA (1975)^4 .
B) Acclimation Procedure
The bluegill sunfish (Lepomis maoroahiru8)B`, rainbow trout (Salmo gairdneri), and fathead minnows (Pimephales promelas) used in this study were obtained from private hatcheries. Stock fish were held in fiberglass holding tanks filled with carbon-filtered well water maintained at 14-15C. A daily photoperiod of 16 hours light and 8 hours dark, with a 30-minute transition period, was maintained throughout the acclimation and testing period. The fish were fed Tetra-Minc daily, food being withheld 48 hours prior to and throughout the test period. Fish were so acclimated for 14 days prior to testing.
Acute short-term (96-hour) static bioassays were performed on FC95 Lot 583.Carbon-filtered well water of known composition
a. Dale Fattig Fish Farm, Brady, Nebraska
001*719
b. Dennis Fender Fish Hatchery, Baltic, Ohio
c. Tetra-Min - a commercial fish food of known composition
3
was used as the diluent. All glass aquaria (35 x 20 x 20 cm), containing 16.1 of diluent or diluent plus toxicant comprised a study chamber. Fathead minnows (Pimephales promelaa), bluegill sunfish (Lepomis maoroohirus), and rainbow trout (Salmo gaivdneri)t uniform in size and weight, were tested at each chemical concentration of each test material. Test fish were randomly assigned to various test chambers within 30 minutes following toxicant addition. Test' temperatures for the fathead minnow and bluegill sunfish were maintained at 18 C range 17-19, while the rainbow trout tests were conducted at 14C. Mortality, temperature, dissolved oxygen level, and pH of all test solutions were measured at 24-hour intervals or until total / mortality had occurred. General observations relative to behavioral changes were similarly recorded when appropriate. Organisms used in this study were considered to be generally healthy and free of disease.
Instrumentation used included a temperature compensating Orion pH meter, ASTM thermometers -1C. for temperature monitoring, and a Yellow Springs Dissolved Oxygen meter.
All aquatic studies were replicated. LC__ values with 95% confidence limits were calculated using the DSEPA (Duluth) Probit computer program on the 3M TRAC System.
C) Aquatic Invertebrates - 48 hour Static LC^q
Daphnia magna, 20 organisms per test, were exposed to FC 95, lot 583 at varying concentrations for 48 hours. First instars were counted and placed in carbon filtered well water, with chemical added and solubilized prior to the addition of the Daphnia magna.
Test concentrations were 42, 56, 75, 100 and 135 mg/1.
LC_0 values with 95% confidence limits were calculated using the USEPA (Duluth) Probit computer program on the 3M Trac System.
The test protocol utilized for this study was modeled after that described by USEPA (1975)'" .
Results
Table 1 lists water solubility and partition coefficient data obtained using radio^labelled FC-95.' This material is water soluble, 286 ppnr , slightly lipid soluble having a partition coefficient of .7-10.^ . Based on these data it can be concluded that FC 95 would not bioconcentrate to an appreciable extent in the environment. Chiou et al/ ' have described an emperical relationship between water solubility of a chemical and its bioconcentration factor. In this system the ascribed error is considered to be one order of magnitude. When applying the data generated for FC 95 to this proposed relationship this chemical would be projected to possess a bioconcentration factor of approximately
200 001720
3
was used as the diluent. All glass aquaria (35 x 20 x 20 cm), containing i6.1 of diluent or diluent plus toxicant comprised a study chamber. Fathead minnows (Pimephalee promelas), bluegill sunfish (Lepomie maorochime), and rainbow trout (Salmo gairdneri), Uniform in size and weight, were tested at each chemical concentration of each test material. Test fish were randomly assigned to various test chambers within 30 minutes following toxicant addition. Test temperatures for the fathead minnow and bluegill sunfish were maintained at 18C range 17-19, while the rainbow trout tests were conducted at 14C. Mortality, temperature, dissolved oxygen level, and pH of all test solutions were measured at 24-hour intervals or until total mortality had occurred. General observations relative to behavioral changes were similarly recorded when appropriate. Organisms used in this study were considered to be generally healthy and free of disease.
Instrumentation used included a temperature compensating Orion pH meter, ASTM thermometers -1C. for temperature monitoring, and a Yellow Springs Dissolved Oxygen meter.
All aquatic studies were replicated. LC5Q values with 95% confidence limits were calculated using the USEPA (Duluth) Probit computer program on the 3M TRAC System.
C) Aquatic Invertebrates - 48 hour Static LCgQ
Daphnia magna, 20 organisms per test, were exposed to FC 95, lot 583 at varying concentrations for 48 hours. First instars were counted and placed in carbon filtered well water, with chemical added and solubilized prior to the addition of the Daphnia magna.
Test concentrations were 42, 56, 75, 100 and 135 mg/1.
LC_0 values with 95% confidence limits were calculated using the USEPA (Duluth) Probit computer program on the 3M Trac System.
The test protocol utilized for this study was modeled after that described by USEPA (1975)'1 .
Results
Table 1 lists water solubility and partition coefficient
data obtained using radio-rlabelled FC-95.' This material
is water soluble, 286 ppm'- ', slightly lipid soluble having
a partition coefficient of _7-10. . Based on these data
it to
can be concluded that an appreciable extent
FC in
95 would not bioconcentrate the environment. Chiou et
al
(
6
)
have described an emperical relationship between water
solubility of a chemical and its bioconcentration factor.
In this system the ascribed error is considered to be one
order of magnitude. When applying the data generated for
FC 95 to this proposed relationship this chemical would
be projected to possess a bioconcentration factor of approximately
200 001721
4
TABLE 1 - Physicochemical Characterization of FC-95
Parameter Solubility
Partition Coefficient
Test Veith Method
n-octanol/water
Results 286 ppm
7-10
FC-95 was found to be completely resistant to biodegradation under the test conditions employed' '. This 2 1/2 - month shake culture biodegradation study utilized microbial test cultures derived from activated sludge inocula obtained from the waste treatment systems of Chemolite, Decatur, and the Twin Cities Metro plants. During the period of this study, a strain of microbes which could degrade FC-95 did not develop, hence this material would be expected to persist in the environment for extended periods of time unaltered by microbial catabolism.
In working with fluorochemicals, it has been suggested that if these materials do degrade either chemically or biolog ically that one degradation product would be FC-95. We have never observed the formation of FC-95 by either of these routes', therefore, the environmental levels of FC-95 are not anticipated to increase as a result of the exogenous production of this material.
Soil sorption studies have shown that approximately 18.8% (range 14.6-27.0) of the FC 95 is adsorbed to the Brill sandy loam soil used in these studies (Table 2)(3). Complete desorption of the FC 95 which had been adsorbed to soil was accomplished within three (3) desorption trials (Table 2). Mobility of FC 95.was calculated utilizing the scheme devised by Hamaker'1 'whereby adsorption coefficients are converted to a constant, K , which reflects the organic content of the soil. Hamaker has shown that the relative mobility of a group of pesticides could be determined in this fashion and that a relative ranking, moving from highly mobile to immobile materials would result. In applying this test, FC 95 had a K value of 45, being considerably more mobile than Paraquat; K 20,000 and slightly less mobile when compared to Chloramben, K 12.8. These data indicate that those forces which bindocFC 95 to soil are weak, hence the complete desorption of material adsorbed to the soil and secondarily the fact that this material is highly mobile.(3).
Results of the acute static aquatic tests are tabulated (Table 3). Based on aquatic toxicity criteria established by NIOSH FC 95 would be considered slightly toxic to.the vertebrates and invertebrate utilized in this test' . It is noted that the invertebrate data correlate well
001722
5
with those data obtained when testing both warm water species. This observation has been made repeatedly, therefore, one may consider Daphnia magna data as a valid predictor of chemically induced toxicity to warm water vertebrate species (9,10). A statistical analysis will be utilized to validate this concept.
Egg-fry studies were contracted to EG&G Bionomics Laboratory, and their results comprise Tables 4 and 5. These studies were undertaken to assess the effect of 14C FC 95 at sublethal levels on hatchability, survival, weight and length changes (Table 4). It is generally accepted that the immature or young of a species are quite sensitive indicators of chemically induced toxicity. In the parameters under investigation the percent survival was statistically reduced (P.05) at a FC 95 concentration of 1.9 mg/1. The remaining test parameters were unaffected by this chemical. The mechanism responsible for the increased mortality observed at the highest test concentration can not accurately be determined based on these studies, although it is to be noted that hatchability was not affected at this dose level.
In the contracting laboratory's report, the observation was made that the fish in the 1.9 mg/1 tank were exhibiting stress behavior; erratic swimming, darkened coloration. A similar observation was made of a few fish in ttye 1.0 mg/1 tank suggesting that the toxic action of FC 95 is cumulative;
Based on the results of the histopathological examination, a 30-day exposure to 1.9 mg/1 14 C FC 95 did not contribute to abnormal histopathology (Table 5).
TABLE 2 - Soil Sorption Test on FC 95
Parameter
Test
Solution
Soil Sorption
Adsorption
Water
Desorption
Water
Koc
Results
18.8%
100% of amount adsorbed 45
001723
6
TABLE 3 FC 95: 96 Hour Acute Static Testing
Test Organism
96h LC- mg/l 50
Fathead Minnow
37.6 51
Bluegill Sunfish
68
Rainbow Trout
11
B. Invertebrate 48 Hour Static Test
Daphnia Magna
50 49.2
Limits
lower mg/1
Upper mg/i
28.4 46
50.2 56
62 74
8.6 12.5
42.8 38.7
56 56.6
001724
7
TABLE 4
Percentage Hatch, Percentage Survival, Mean Total Length and Average Wet Weight of Fathead Minnow Fry (Pimephalea promelae) during Exposure to Varying Concentrations of14C FC 95.*
30 Days Post Hatch
Concentration mg/1
Hatch %
Survival %
Total Length mm
Wet Weight mg
1.9 95 42C 20.5 72
1.0
96.5
86
20
62.5
0.45
96.5
90
20.5
66
0.28
95.5
94
21
64
0.12
97.5
95
20
63
Control
98
93
20
61.5
Solvent Control 89
100
21
64.5
SiWork performed by EG&G Bionomics Laboratory, Inc.
^Summary table submitted to Environmental Laboratory, 3M, St. Paul, as part of final report.
cSignificantly reduced at P = 0.05
TABLE 5 Histopathological Examination of Fathead Minnow 14 CPimevhalee promelas) exposed 30 day to 1.9 mg/lA*C FC 95*'D
Test Material
Number of Observations
Histopathological Findings
Control 114CFC 95
10 9/10 fatty liver change 1/10 bacterial gill disease 9/10 tissue autolysis
10 8/10 fatty liver change 2/10 normal
g
Work performed by EG&G Bionomics Laboratory, Inc.
^Summary table submitted to Environmental Laboratory, 3M, St. Paul, as part of final report.
001725
-8 -
Both groups of organisms exhibited fatty liver changes, control, 9/10, and dosed organisms 8/10. Evidence of tissue autolysis in the control group is indicative of a delay in histological preparation of tissues following death of the organism. . Discussion The primary purpose of this report is to provide a single source for all environmental data generated relating to FC 95 and to provide an analysis of potential environmental risk. The environment may be considered to be a closed system which can be depicted as follows:
Air Soil
Water It, therefore, follows that chemicals entering this system may establish an equilibrium, remain within a single environment, or impact on all phases of the depicted cycle. In the specific case at hand we can represent the impact *of FC 95 in the following manner: No Photodegradation ^__ Air ^ Volatility ?_____ Soil__ ^No Biodegradation
Projected to minimally bioconcentrate, low lipophilicity
As schematically represented above FC 95 enters the environment primarily by means of the waterways and secondarily via the terrestrial ecosystem and atmosphere. FC 95 does not adsorb permanently to either soil and/or sediment. Complete desorption of FC 95 from soil did occur in the laboratory model' . It is unknown whether or not this material volatilizes, a fact which assumes importance in light,of the finding that FC 95 does not undergo photolysis. ' Based on the foregoing it appears that waterways are the environmental of)*] sink for FC 95 and aquatic organisms are the intermediate
9
receptors. It is in the aquatic area that a possible deleterious action of FC 95 may be found.
As noted above, reduced survival rates of fathead minnow fry were recorded at FC 95 concentrations of 1.9 ppm. The no eff'ect level of FC 95 may be assumed to be approximately 0.19 ppm. These data may serve in a predictive fashion, hence the above noted levels of FC 95 may impact on a human food source by significantly reducing the survival rates of these organisms.
It is to be emphasized that the environmental concentration of FC 95 more accurately describes the degree of risk associated with this chemical.
We have made several *assumptions which are basic to the simplistic model used in our calculations:
1) Total production is at Chemolite and it is discharged in its entirety.
2) No FC 95 is removed by the treatment facility.
3) All effluent is discharged to the Mississippi River.
4) FC 95 is discharged uniformly.
5) River flow and all other parameters are constant, hence not subject to seasonal and/or climatic conditions.
The formulae used in these projections include:
3 (River Flow, CFM)(Conversion.gal/ft )(Time.min)
1) MG/min = .
Production, per annum
2) MG/min X 1440 - MG/Day
3) Lbs/day = (mg/1 X wt. lbs. H^O per gal)(MG/Day)
Mississippi River flow at Hastings, MN, based on a 10 year low flow record is 10,000 CFS.
The total 5-year production figures were provided by D. R. Ricker, Commercial Chemicals Division. In utilizing these figures an estimated environmental concentration of FC 95 in the Mississippi River below Chemolite was calculated. During the period 1973-1978, the EEC for FC 95 was calculated to be 5 ng/1 at Hastings, MN, while the EEC projected for the period 1978-1983 is projected at 7 ng/1. Since the water compartment is the environmental sink for FC 95 it is determined that at the present and projected levels of production, FC 95 will not present an unreasonable environmental risk.
001727
v"l . r '
10
Conclusions
Under the test conditions employed in characterizing the physicochemical and environmental properties of FC 95 it has been determined that this material:
1) is water soluble, 286 ppm
2) has an n-octanol/water partition coefficient o f -'-10
3) is resistant to microbial degradation
4) is highly mobile in Brill sandy loam soil
5) In a contracted study, survival rate of the fathead
minnow fry was reduced to a statistically significant
extent when the exposure concentration was 1.9 mg/1
FC 95. No other parameters were adversely affected
nor was abnormal histopathology observed at this dose
level.
6) would have an estimated environmental concentration
of approximately 7 ng/1 under conditions, wherein all
FC 95 were manufactured at Chemolite and would be discharged
uniformly into the Mississippi River.
7) may not be a metabolite as a result- of chemical or
biological degradation, hence no increase in environmental
levels of FC 95.
8) FC 95, under the test conditions described will not
present an unreasonable environmental risk.
Bibliography
1. Mendel, A., Technical Report. "Analytical Methodology and Support", January 17, 1979.
2. Reiner, E.A., Technical Report: Biodegradation Studies of Fluorocarbons ^ III, July 19, 1978.
3. Welsh, S.K., Technical Report. Adsorption of FC 95 and FC 143 on Soil, February 27, 1978.
4. US/EPA - Methods for Acute Toxicity Test with Fish, Macroinvertebrates and Amphibians, Ecological Research Series 660/3-75-009, 1975.
5. Unpublished data
6. Chiou, Cary T . , Virgil H. Freed, David W. Schmedding, and Rodger L. Rohnert: Partition Coefficient and Bioaccumulation of Selected Organic Chemicals, Environmental Science and Technology 11(5): 475-478, 1977.
7. Hamaket, J.W., "Interpretation of Soil Leaching Experiments" Chemicals, Human Health and the Environment, A Collection of Dow Scientific Papers, Vol. 1, Dow Chemical USA, Midland, Michigan 48640.
001728
- 11 -
#*
8. Registry of Toxic Effects of Chemical Substances, '76 Edition, Christensen, H.E. and E.J. Fairchild, Eds. p.xv and Ci, U.8. Department of Health, Education and Velfare; National Institute for Occupational Safety and Health, Washington, D.C., June, 1976.
9. Welter, A.N., Technical Report: Aquatic Toxicity Studies: FC 214-30 Lot 566, February 16, 1979.
10. Welter, A.N., Technical Report: Aquatic Toxicity Studies:
FC 232 Lot 610, January 17, 1979.
r
11. Todd, J.W., Technical Report: FC 95/Photolysis Study Using Simulated Sunlight/ January 9, 1979.
001729
