Document 91BZ4xLpGkGvBbznqEM77vBEe

AR& -0 H % BIOCONCENTRATION TEST SUBSTANCE Identity: Perfluorooctanoic acid, ammonium salt; may also be referred to as PFOA ammonium salt, Ammonium perfluorooctanoate, PFO, FC116, FC-126, FC-169, orFC-143. (Octanoic acid, pentadecafluoro, ammonium salt, CAS # 3825-26-1 ) Remarks: The test sample is FC-143. It's purity was not sufficiently characterized, though current information indicates it is a mixture of 96.5 100% test substance and 0 - 3.5% C6, C7, and C9perfluoro analogue compounds. The 3M production lot number 377. METHOD: Method/guideline followed: 3M derived preliminary investigation outlined in the Technical Report Summary. Investigation included method development for the analysis of fluoride by combustion. Type: Static exposure with static clearance phase. GLP (Y/N): No Year: 1995 Species: Fathead minnow (Pimephales promelas) Supplier: Aquatic Biosystems, Inc., Fort Collins, CO. Analytical monitoring: Whole fish and test solutions were combusted in a modified organic halide analyzer (Dohrmann DX-2000). F' activity in collection fluid was then measured with an ion-selective electrode connected to an Orion Research ion analyzer. The concentration of PFO was then calculated from the F' ion concentration. Length and weight: Not noted in the report. Uptake period: 13 days Depuration period: 15 days Statistical methods: One-way analysis of variance and Tukey's HSD test (alpha = 0.05) were used to compare the average concentrations of PFO in tissues from PFO-exposed fish during the uptake and depuration experiment. Test fish age: 64 days Loading: 124.6 + 20 mg fish (wet wt.) per liter test solution. Pretreatment: Not noted. Test conditions: Dilution water: Carbon-filtered well water from 3M Well #2, St. Paul, MN Dilution water chemistry: hardness: 272 + 8 mg/L as CaCOz alkalinity: 232 + 8 mg/L as CaC03 pH: 8.5 + 0.1 Conductivity: 510 + 14 pmhos/cm Dissolved oxygen: 8.5 + 0.3 mg/L 003708 Stock and test solution preparation: The primary stock solution was prepared by dissolving solid PFO in dilution water to create a 1000 mg/L concentration. The nominal concentration of 25 mg/L was obtained by diluting an aliquot of the stock solution to 15 liters using dilution water. Exposure vessels: 5 gallon cylindrical high density polyethylene tanks containing 15 liters of test solution. Number of replicates: One Number offish per replicate: 30. Number of concentrations: One plus blank control Water chemistry during the study: Dissolved oxygen: The DO concentration of the control dropped below 6.0 mg/L at 72 hours after the start of the test. Aeration was initiated at this point and continued throughout the test to maintain DO levels at or near 100% saturation. Test temperature: 20+1 C Average pH (control and test solutions): 8.2 + 0.2 Photoperiod: 16 hours light and 8 hours dark. Feeding: Fish were fed live brine shrimp every 48-hours beginning 24hours after starting the test. Sampling: Five fish were removed from each tank at 192 and 312 hours during the uptake phase and again 24, 96, 168, and 360 hours after being transferred to clean dilution water. Remarks field: Fecal material / excess food was removed from tanks as needed. DO measurements were taken daily. Test solution pH was measured once more at the end of each experimental phase. C -03709 RESULTS Concentration of PFO measured in test solutions. Phase / Solution UPTAKE Phase Time (hours)* Average PFO Concentration (ug/mL) Standard Deviation Control 0 <1 192 <1 312 <1 - - 25 ug/mL PFO DEPURATION Control clearance tank solution 0 192 312 0 168 360 25.0 25.5 25.9 <1 <1 N ot available 1.8 2.2 1.8 _ - 25 ug/mL PFO exposed clearance tank 0 168 <1 <1 - 360 N ot available * Elapsed time (hours) from the beginning of each experimental phase. Average concentration of PFO (measured as F-) in Pimephales promelas tissues Time PFO n Fish Comparison (Hours) pg/g Standard Of wet weight Deviation Means ** 0 1.7 0.4 C 192 44.7 9.1 A 312 46.7 5.8 A 336 (24)* 19.9 5.1 B 408 (96) 7.6 1.3 C 480 (168) 7.6 3.5 C 672 (360) 8.0 1.6 C * Number in () indicates elapsed time (hours) from beginning of depuration phase ** Means with the same letter are not significantly different at alpha = 0.05 by the Tukey-Kramer Honest Significant Difference test. The calculated 312 hour BCF for PFO is 1.8 using the equation BCF = Ca/ Cw where Ca is the equilibrium concentration of the test substance in the fish and Cw is the equilibrium concentration of the test substance in the water to which the organism is exposed. 003710 CONCLUSIONS No definitive conclusions can be derived from this study. General observations can be made. PFO concentrations increased in the fish tissues over the course of exposure. The PFO in fish tissue appeared to be directly related to the concentration of PFO in the test solution. While concentrations decreased in the whole fish samples over the period of the clearance phase, the time required for complete removal is longer than the 15 days used in the test. The concentration of PFO in test solutions remained constant during the static exposure experiment. Relative to the control treatment, the survival and growth of the test fish exposed to PFO were not adversely affected during the experiment. Submitter: 3M Company, Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133 DATA QUALITY Reliability: Klimisch ranking 2. This study meets the criteria for quality testing, however, there was no definitive analysis of the compound in either the fish or the test solutions. It was measured indirectly as F" ion. This would not allow for the determination of degradation or metabolism byproducts and could yield falsely high readings. There was also no consideration for the possibility that the test substance may have been sorbed to the surface of the fish rather than residing internally, thus possibly overestimating the BCF. The study lacks characterization of the test substance purity. Third party review by Dr. John Giesy of Giesy Ecotoxicology, Inc. (observations included with report) verifies the studies strengths and weaknesses. REFERENCES 3M Technical Report "Assessment of the Bioaccumulative Properties of Ammonium Perfluorooctanate: Static" R.D. Howell, J.D. Johnson, J.B. Drake, R.D. Youngblom , May 31,1995 3M requested expert overview, "Bioaccumulative Properties of Ammonium Perfluorooctanoate: Static Fish Test", Dr. John P. Geisy of Geisy Ecotoxicology, Inc., March 20, 1995 003711 OTHER Last changed: 5/24/00 003712 Technical Report Summary ,FonD <747r,1t>K To: Patent & Technical Communications Services - 201-2C-12 Report Summerymustbe typewritten. GuideSnetere on reveree aide. Document o**urmi*N>*** n m n o tm Num ber 0222 To D. L. BACON A uttw r(t) R. D. HOW ELL. J. D. JOHNSON, J. B. DRAKE, R. D. YOUNGBLOM O N M onlO opH niont CC Loo ENVIRONMENTAL TECHNOLOGY & SERVICES 01 089 Project Oeecrtptlon METHOD DEVELOPMENT Report TWo Assessment of the Bioaccumulative Properties of Ammonium Perfluorooctanate; Static Keywords Bioaccumulation; Ammonium perfluorooctanoate; fish; static fish test Report Humber (Ptooe addMonal tU Le in Abetrect ene) Dele Typed 05/31/95 Employee Numbers) 295864 / 7288 OrBantatton Code Pertod Covered May 1 99 4 -M ay 1995 Project Objective & Report Abstract Procedures are described that were used for obtaining laboratory data for the uptake and depuration of ammonium perfluorooctanoate (PFO ) by the fathead minnow, Pimephales promelas, from dilution water using a static exposure technique. These procedures were intended to provide background information on the bioaccumulation of PFO in fish. sport ype g j R AD Research and Development PILot Plant MANufacturing Management SUMmary TRP Trip or Field Report FACtoiy Experiment O ENGineering ROI Record of Invention TECh. Service 60VL Project OTHER security NotebookReTerenee q Open Report and Summary IfdoRiwUonUaleonInttWe H C ioe^ Report - Open Summary 3M Chemical New Chemicals Reported R l^lltry UeeformS0S2toenterIntoCbemfeelReplaiy Use O niyf* y ^ - ,4 If report is printed on both sides of paper, send tw o copies to P & TCS. 003713 ASSESSMENT OF THE BIOACCUMULATIVE PROPERTIES OF AMMONIUM PERFLUOROOCTANOATE: STATIC FISH TEST ABSTRACT : Procedures are described that were used for obtaining laboratory data for the uptake and depuration of ammonium perfluorooctanoate (PFO) by the fathead minnow, Pimephales promelas, from dilution water using a static exposure technique. These procedures were intended to provide background information on the bioaccumulation of PFO in fish. QftlECTIVES To accomplish a preliminary investigation of PFO uptake and depuration in fish. This investigation included method development for analysis of fluorine by combustion. METHODS: Summary of Practice The uptake and depuration test was conducted using a static (test solutions were not renewed) exposure system. During the uptake phase of the experiment, fish were exposed for 13 days to dilution water to which a selected concentration of PFO had been added. Following the uptake phase, fish were transferred to dilution water which did not contain added PFO for a 15 day depuration phase. A control treatment, in which fish were exposed to dilution water to which PFO had not been added, was included with the test. The control provided a measure of the acceptability of the test by giving an indication of the quality of the test fish, and the suitability of the dilution water, food, test conditions, and handling procedures. During both phases of the experiment, fish and water samples were removed periodically from test chambers and analyzed for PFO. Apparatus Facilities - All fish tests were conducted at the 3M Environmental Laboratory in St. Paul, MN. Proper test conditions (temperature, photoperiod, and ventilation) were maintained with the use of a controlled environment chamber (REVCO Scientific Inc., Asheville, NC). 1 003714 Test Chambers - Fish and test solutions were contained in 5 gallon cylindrical high density polyethylene tanks (Nalge CO., Rochester, NY). Dilution Water Source - Dilution water was obtained in the 3M Environmental laboratory from an on-site well (3M Well #2, St. Paul, m n ). Treatment - Dilution water was carbon-filtered prior to collection using a commercial filtration system (Culligan Water Conditioner, Culligan International CO., Northbrook, IL). Before use, dilution water was aerated for at least 12 hours in order to bring the pH and concentrations of dissolved oxygen and other gases into equilibrium with air. Characterization - Carbon-filtered, aerated well water had the following characteristics (MEAN S.D.): pH, 8.5 0.1; dissolved oxygen, 8.5 0.3 mg/L; conductivity, 510 14 Hmhos/cm; alkalinity, 232 8 mg/L as CaC03, hardness, 272 8 mg/L as CaC03. Test Material General - Commercial PFO (Specialty Chemicals Division, 3M Company, St. Paul, MN, Lot #377) was used for the test. Acute Toxicity - The P. promelas 96 hour LC50 for PFO was determined to be 766 mg/L (3M Environmental Laboratory, unpublished data). Test Concentrations - Fish were exposed to dilution water containing a nominal concentration of 25 mg/L PFO during the uptake phase of the test. An earlier study (3M Environmental Laboratory, unpublished data), indicated that while this concentration did not adversely affect P. promelas, it was great enough to allow for the accurate measurement of PFO in test solutions and fish tissues. Stock Solutions - 1000 mg/L PFO stock solutions were prepared by dissolving solid PFO in dilution water. Test Organism Species - The freshwater fathead minnow, Pimephales promelas, was used as the test organism. Source - Test fish were obtained from an external bioassay supply laboratory (Aquatic Biosystems, Inc., Fort Collins, CO) . Care and Handling - Fish were maintained at the 3M Environmental Laboratory in 50 gallon flow-through tanks 2 003715 (Frigid Units, Inc., Toledo, OH) containing carbon-filtered dilution water. Fish were allowed to acclimate to the dilution water for at least 12 days before being used for testing. The concentration of dissolved oxygen in the holding tanks was maintained near 100% saturation by continuous aeration. Fish were fed live brine shrimp and/or TetraMin flake food (TetraWerke, Germany). Water temperature remained relatively constant at approximately 14 c. Age - All fish were 64 days old at the start of the test. Procedure Summary. Test Parameters * Test temperature: 20 i 1 C * Photoperiod: 16 h:8 h (light:dark) * Test solution volume: 15 L * Test solution renewal: none * Nominal test concentrations (uptake): 0.0 (Control) and 25 mg/L PFO * No. replicates per test concentration: 1 * No. organisms per test concentration: 30 * Length of uptake phase: 312 h (13 days) * Length of depuration phase: 360 h (15 days) * Feeding: fish were fed live bring shrimp Uptake/Depuration Experiment Description - The uptake/depuration experiment involved exposing P. promelas under static conditions to dilution water to which PFO had been added. The uptake phase was conducted for a period of 312 h (13 days). After 312 h, the fish were transferred to dilution water to which PFO had not been added. This portion of the experiment, the depuration phase, lasted for 360 hours (15 days). Fish and test solution samples were taken at the beginning and end of each phase, and periodically throughout each of the experimental phases. Test Set-Up (Uptake) - Two test tanks were filled with carbon-filtered, aerated dilution water. One tank was dosed with the appropriate volume of 1000 mg/L PFO stock solution to produce 15 L of solution at a nominal concentration of 25 mg/L PFO. The second tank contained only dilution water and served as a control. Dissolved oxygen and pH were measured in the test solutions. A sample of test solution was taken from each tank and stored at 4 C in 6 mL polypropylene scintillation vials (Wheaton Scientific, Millville, NJ) until needed for PFO analysis. Thirty P. promelas were added to each of the test tanks. Ten additional fish were sacrificed and their wet weights were 3 003716 determined in order to calculate loading rate. Each of the ten fish was placed in a separate 15 mL polypropylene centrifuge tube (Corning Inc., Corning, NY) and stored at -25 C until analyzed for background PFO concentration. rest Sec-Up (Depuration) - Following the uptake phase of the experiment, remaining fish were transferred to two test tanks containing only 15 L carbon-filtered, aerated dilution water. Dissolved oxygen and pH were measured in each tank following transfer of fish, and test solution samples were taken from each tank for PFO analysis. Test Maintenance - Dissolved oxygen measurements in the test tanks were taken daily during both phases of the test. If the dissolved oxygen concentration in either of the test tanks fell below 6.0 mg/L, both tanks were gently aerated for the remainder of the test. Fish were fed live brine shrimp 24, 72, 120, 168, 240, 288, 336, 384, 432, 480, 528 and 576 h after starting the test. Fecal material/excess food was removed from tanks with a disposable glass pipette as needed. Test solution pH was measured once more at the end of each experimental phase. Test Sampling - Five fish were removed from each tank at 192 and 312 h during the uptake phase and again 24, 96, 168 and 360 h after being transferred to clean dilution water. Fish were sacrificed by freezing in liquid nitrogen. Fish were allowed to thaw, and wet weights were determined. Each fish was placed in a separate 15 mL polypropylene centrifuge tube and stored at -25 C until needed for analysis. Test solution samples were taken at each fish sampling time and stored in 6 mL polypropylene scintillation vials at 4 C until needed for analysis. Analysis of PFO Whole fish and test solutions were combusted in a modified organic halide analyzer (Dohrmann DX-2000, Rosemount Analytical Inc., Santa Clara, CA), and F~ activity in collection fluid was measured with an ion-selective electrode connected to an ion analyzer (Orion Research Inc., Boston, MA) . The concentration of PFO in whole fish tissue and test solutions was calculated from the measured concentrations of F~ ion. Data Analysis At each sampling point, the weight of PFO-exposed fish was compared to that of control fish using a t-test (alpha = 0.05). One-way analysis of variance and Tukey's HSD test (alpha = 0.05) were used to compare the average concentrations of PFO 4 003717 in tissues from PFO-exposed fish during the uptake and depuration experiment. RESULTS: Test Organism Loading Rate The loading rate of P. promelas was 124.6 20 mg fish (wet wt.) per liter of test solution. Water Quality Characteristics Measured water quality parameters remained within acceptable levels during the static experiment. The average pH of both the control and PFO test solutions was 8.2 0.2 for the entire test. The dissolved oxygen concentration of the control solution dropped below 6.0 mg/L 72 h after starting the test. Therefore, aeration of the test solutions was initiated at 72 h, and continued throughout the remainder of the experiment. With aeration, the dissolved oxygen levels in both test solutions remained at or near 100% saturation. Concentration Of PFO In Test Solutions The concentration of PFO in test solutions remained constant during the static exposure experiment. During the uptake phase, the measured concentration of PFO in spiked dilution water was consistent at approximately 25 mg/L (Table 1). In all other test solutions, during either phase, PFO concentrations were always less than 1.0 mg/L. Survival And Growth Of Test Fish Relative to the control treatment, the survival and growth of P. promelas exposed to PFO were not adversely affected during the experiment. The percent survival of the control fish and the PFO-exposed fish were 97 and 93, respectively. In addition, the average wet weight of PFO-exposed P. promelas did not differ significantly from the average wet weight of control fish at any of the sampling points (Table 2, Figure 1) . Concentration Of PFO In Test Fish Uptake and Depuration The concentration of PFO measured in fish tissue was directly related to the concentration of PFO in test solution. At the beginning of the uptake phase, the PFO concentration in fish tissue was < 1.0 |ig/g (wet wt.). After 192 and 312 h of 5 003718 exposure to PFO in dilution water, the average concentration of PFO in fish tissue was 44.7 and 46.7 \ig/g (wet wt.), respectively (Table 3, Figure 2). The concentration of PFO in fish did not differ signficantly between 192 and 312 h of exposure, but was significantly greater at both of these sampling times than at O h . 24 h after being transferred to clean water, PFO-exposed fish had an average PFO tissue concentration of 19.9 \ig/g (wet wt.). At 96 h post-exposure, the concentration of PFO in PFO-exposed fish had decreased to approximately 8 |ig/g (wet wt.), and remained relatively constant until test termination at 360 h (cumulative test time = 672 h ) . The concentration of PFO in fish tissue at 96, 168 and 360 h post-exposure did not differ significantly from that measured at test start (Oh). Bioconcentration Factor The relationship between exposure to PFO and the amount of PFO in the tissue of P. promelas was described by a bioconcentration factor (BCF). Bioconcentration refers to the increase of a pollutant concentration from water when passing directly into an aquatic species (Moriarty 1983) . The BCF was defined as: BCF = Ca/Cw where, Ca = equilibrium concentration of a pollutant in the aquatic organism, and Cw = equilibrium concentration of a pollutant in water to which the organism is exposed. Because the concentrations of PFO in test solution and fish tissue did not change between 192 and 312 h, the assumption was made that an apparent equilibrium, or steady state, had been reached in the static exposure system. Therefore, the P. promelas 312 h apparent steady-state BCF (BCF312h) for PFO was calculated as the concentration of PFO in fish tissue at 312 h divided by the concentration of PFO in test solution at 312 h, or ' BCF3i2h = 46.7 ig/g (wet wt.)/25.9 ig/mL = 1.8. REFERENCES Moriarty, F. 1983. Ecotoxicology: The Study of Pollutants in Ecosystems. Academic Press, Inc., Orlando, FL, 233 p. 233. 6 003719 FIGURE 1. Average wet weights of Control group and PFO-exposed P. promelas sampled throughout Uptake/Depuration experiment. 3 bO tH <D rH oo 0 100 200 300 400 500 600 700 a W O Time (h) FIGURE 2. Uptake and depuration of PFO by P. promelas Time (h) TABLE 1. Concentration of PFO measured in test solutions. Phase/ Solution UPTAKE Control 25 [ig/mL (N) PFO Phase A v g . PFO Time (h)* Cone. (ua/mL) Std. Dev. 0 <1 192 < 1 312 < 1 - 0 25.0 1.8 192 25.5 2.2 312 25.9 1.8 DEPURATION Control 0 168 360 <1 <1 - 0 <1 - 168 < 1 - 360 * Elapsed time (h) from the beginning of each experimental phase. ** Test solution containing PFO-exposed fish.____________________ 003722 TABLE 2. Average wet weights of Control group and PFO-Exposed P. promelas. Time (h) 0 192 312 336 (24)* 408 (96) 480 (168) 672 (360) Control Fish Average Wet Wt. (a) Std. Dev. 61.7 5.2 61.4 20.8 55.3 11.7 49.4 13.9 66.4 7.3 73.2 44.4 32.7 16.8 PFO-Exposed Fish Average Wet Wt. (g) Std. Dev. 61.7 5.2 57.8 13.4 51.5 42.0 55.5 22.4 65.8 22.4 74.6 55.8 53.6 16.9 * Number in ( ) indicates elapsed time (h) from beginning of depuration phase. Results of t-test (a=0.05) comparing wet weights of control and PFO-exposed fish sampled at the saune time. Not Significant._________ P n . s .* n.s. n.s. n.s. n.s. n.s. n.s. 003723 TABLE 3. Average concentration of PFO (measured as F-) in P. promelas tissues. Time (h) 0 192 312 336 (24)* 408 (96) 480 (168) 672 (360) PFO Iii Fish (ng/g, wet w t .) Std. Dev. 1.7 0.4 44.7 9.1 46.7 5.8 19.9 5.1 7.6 1.3 7.6 3.5 8.0 1.6 Comparison Of Means** C A A B C C C * Number in ( ) indicates elapsed time (h) from beginning of depuration phase. ** Means with the same letter are not significantly different at alpha=0.05 by the Tukey-Kramer Honest Significant Difference test._________________________ _____________ 003724 Appendix Comments from Dr. John Giesy, Michigan State University C 03725 M arch 20, 1995 Dr. R obert Howell 3-M Corp. Environ. Lab. Building 2-3E-09 P.O . Box 3331 St. Paul, M N 55113 D ear Robert: I have reviewed the report entitled Assessm ent o f the Bioaccum ulative P roperties o fArnmonittm Perfluorooctanoate: Static Fish Test, which prepared by James Drake. I found no fatal errors in the experimental design, methods, data interpretation or conclusions drawn from this study. I have attached a short report winch contains my specific comments on the study that was conducted and suggestions for future studies. Please contact me if you have additional questions. Sincerely, JohnP. Giesy, Ph.D. enc: R eport C 03726 Bioaccumulative Properties o fAm m dfflfflffierfluorooctanoate: Static Fish Test, which was prepllga*liy James Drake. JohnP Ph-D. MarP^I995 Dr. R o tte c i! Howell Environ. Lahu&uliing 2-3E-09 P .O S S & *331 S t PaA & S 55113 Comments: G eneral: 1) The set o f experiments was well d e s ig t|^ ^ ^ P h e re are no fatal errors in logic, experimental design, methods selected, statistics a p fftie d ^ conclusions drawn. 2) The report is well written and the resiiha.cleglv presented. Gicay Ecotoxicology, Ine. Macchio. 1993 1 603727 hstcopyavaiiable 3) I agree with the conclusions that there is little bioaccumulation o f perfluorooctanoate (FFO) by the fathead minnow. Specific: 1) The use ofthe fathead minnow as a model^ftegies in initial experiments is appropriate and is useful in demonstrating that there is li^Ulhlfeaipcumulation potential o f PFO. However, this experiment does not address the issue~of*Sfc$umulation via food, by this species or larg er. predatory fishes. Some consideration made o f feeding fatheads contaminated with PFO to larger fishes in a longer e x p o se * 2) The exposure period seems to be adeqiJ^^Q ^tablish that the fish had attained a steady state concentration (SSC) from external However, in future experiments it would be useful to conduct the exposure at le ipling period (4-5 days) longer to establish more definitively that SSC had been 3) The results ofthe study indicate that th $ |aft^m u latio n factor is approximately 1.8. While this value indicates that there is little db||pl&tion o fPFO, the true bioaccumulation factor is probably even less. I think that m o s t^ ^ ^ iF O that was accumulated by the fish was due to surface sorption. Thus, the study prd^6l$^erestim ates the true BCF. Base&on the data presented, the true BCF is probably $Ji&&lof eight (8) or nine (9) less than the reported value. I would suggest that in any futurjfsliSi& that the fish be rinsed for approximately four hours in clean flowing water before the;|4ff|gj$ed into the clean water to follow depuration. While the accumulation potential sH H l illative small, relative to other halogenated hydrocarbons, it is not unexpected, basicf'tfiithe structure o f the compound, and similar to the BCF expected for detergents. The current study addressed only a silfp ^ f f iosure concentration. The fact that there was accumulation o f PFO into the fishes not rapidly depurated indicates that there is accumulation into a tightly bound poofe, H gU M that the concentration o f PFO in that pool did not seem to increase during the ex p ^ilS S ^dicates that this pool had become saturated. . If so, this indicates that based on a pharfS6^petic assessment that the BCF could be biased by the use of a single, relatively meats^ ffififee concentration. The existence o f the tightly bound pool suggests that there are two^ft&sSspon components, one very rapid and a second from which there seems to be no depuraffOp^i all during the duration o f the study. I f this is so, then exposure to lesser concentratipnSSPSFO for longer periods o f time would possible result in the same maximum bound PFQ l o a t h e BCF, which is the ratio o f PFO in the fish to that in the water would be g reater.^ in as, the question is, are the pharmaco-kinetic constants true constants, which are iipSlPRfent of exposure concentration. This was not considered in the present study. For instiaacadithe fish were exposed to a concentration one hundredth as great for a longer periodtSll&iigl but still reached the same total body burden, Gioy Ecotoxicology, Inc. Mudt 20,1995 2 BEST COPY AVAILABIE the BCF for PFO accumulation by the fathead minnows would be one hundred (100) times as great. Future studies should include an assessment o f the pharmaco-kinetic constants dependance on duration and intensity of exposure. 4) The duration o f the depuration phase was adequate to establish that the fish had reached a concentration (5 mg/kg, ww) that seemed to be tightly bound in or on the fish and that further depuration was unlikely. The accumitiatiotfcpf as much as S ppm is not a small amount o f compound, if the exposure c o n cen tr^ ^ afe at all relevant for expected environmental concentrations. This result raises thriftiestabn o f where the PFO is associated with the organism. Is it surface-bound or b o u n c^^ ^g tem al tissues o f the fish? I f so, which tissues are the targets for accumulation? 5) While the experiment was not c o n d u d ^ lo ^ s e s s toxicity o fPFO, the results indicate that PFO is not acutely toxic to fathead i&gjggggii This is similar to results with PFO in other studies and consistent with the media&tQfcrahce limit LC-50 of over 700 mg/L. The mechanism of action of p erfl^ jM ^id compounds, which is often peroxisome proliferation, is a more chronic effect|u$Eip&$ adverse effects due this mechanism o f action would not be expected in a s h o rt-te i^ ^ ^ ^ . Thus, the chronic toxicity o f PFO to fish, especially predatory fished, remains an S e ^ s^ stio n . Potential effects on long-term survival, growth and reproduction were not stressed in the bioaccumulation study with fathead minnows. 7) The use of a static system seemsju stifi^ H ^ t Actual concentrations were measured and there was no degradation ofPFO and a constant c l osure concentration was maintained. Future studies with smaller concentrations s h d ^ ^ K id e r the use o f a flow-through system, which is the preferred methodology in defini$HT8$|iies o f bioaccumulation. Potentialfu tu re studies: 1) Disposition o f PFO in fish tissues. I w ||||| g |g e st a radio-tracer study followed by wholeorganism autoradiography. 2) The fact that there seems to be iiTevejaSIgpj& iding o f PFO into the fatheads, indicates that there could be considerable accu m u la^ ^ sjecially from the diet o f predatory fishes. The current study only addressed biogpiujgigation from water. A dietary study or biomagnification study is indicated. 3) Chronic effects o f exposure to PFO on iipftd^&tion o f fathead minnows. This is a relatively straight-forward study to conduct ang^g&tfa rive needed information on the potential for chronic effects on survival, growth arg^gg|guty. Gicsy Ecotoxicology, Inc. Much 20.1995 3 003729 4) The potential for long-term, chronic effects was not addressed in this study or any others. The potential for long-term biomagnification and effects could be assessed in a longer-term feeding study with predatory fishes. Q ijr EeotoxMQfegy, Inc. Much 20.1993 4 005730 PFOA and Associated Saits Synonyms: FC-26, FX-1001, PFO, FC-143, 78.03, FC126, N-2803-3, FX-1003, FC-118, FC-1015, FC-1015-X Physical/Chemical Properties Title Laboratory or Author Date Type Completed Water, acetone and toluene solubilitiy estimates - FC-143 3M Env. Lab Robust summary, 11/17/81 copy of data sheet Environmental Fate and Transport Title R e ad y biodegradation of F C -1 4 3 (B O D /C O D /T O C ) Laboratory or Author 3M Env. Lab T ech n ic al R ep o rt S u m m a ry - Adsorption o f F C 9 5 and F C 14 3 on Soil, and a critique from Dr. S. Boyd, M ichigan S tate University 3M Env. Lab Technical Report S um m ary - Biodegradation Studies of F lu o ro carbo n s - III (F C -1 4 3 ) Technical R eport S u m m a ry - F C -1 4 3 Photolysis Study Using Sim ulated Sunlight T e c h n ic a l R e p o rt S u m m a ry - A n a ly s is fo r F lu o ro c h e m ic a ls in Bluegill Fish, and a critique by J. W . Gillett of Cornell University 3M Env. Lab 3M Agrichemical Lab 3M Env. Lab R ead y biodegradation of F C -14 3 (B O D /C O D ) 3M Env. Lab C alculated octanol w a te r partition coefficient - F C -143 3M Env. Lab Ready biodegradation of FX-1001 (BOD/COD) Ready biodegradation of FC-126 (BOD/COD) 3M Env. Lab Pace Analytical, Minneapolis, MN Completion Type Date 7 /1 4 /7 7 Robust summary, copy of laboratory data summary 2 /2 7 /7 8 , Robust summary, 5 /1 9 /9 3 technical report, critique by S. Boyd (MSU) 7 /1 9 /7 8 Robust summary, technical report 2 /2 /7 9 Robust summary, technical report. 5 /1 /1 9 7 9 , Robust summary, 3 /8 /9 3 technical report, , critique by J. Gillett (Cornell) 6 /5 /8 0 Robust summary, - copies of data sheets. 12 /7/81 Robust summary, copy of calculations Robust summary, computer generated final report, copies of 2/7/85 raw data sheets. Robust summary, computer generated final report, copy of 5/20/87 final report n I 003731