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Ecological Screening Assessment Report on Perfluorooctane Sulfonate, Its Salts and Its Precursors that Contain the C8F17SO2 or C8F17SO3, or C8F17SO2N Moiety

Appendix 5: Risk Quotients for PFOS

Appendix 5: Risk Quotients for PFOS Comparing Concentrations in South Hudson Bay Polar Bears to Effects in Laboratory Mammal Toxicity
Test Organism/ Study TypeReferenceEffectCritical
Effect
Level
Concen-
tration
in Serum
(CTV)
(mg.L-1
Serum)
Concen-
tration
in Liver
at
Critical
Effect
(CTV)
(µg.kg-1
ww Liver)
AFaENEV
(ug.kg-1
Liver)
EEVb
(µg.kg-1 Liver)
Q
(EEV/
ENEV)
Rat receiving 0, 0.5, 2,
or 5 ppm PFOS-K salt
in diet for 104 weeks
(2 years)
Covance 2002 Microscopic
changes in liver
LOEL (m/f)
= 2.0 ppm diet
(0.06 to 0.23

mg.kg-1 bw/d)
13.9 mg.L-140800
(40.8
µg.g-1)
10040837709.24
Monkeys administered
0.03, 0.15, 0.75 mg.kg-1
bw/d PFOS for 26 weeks
Covance Labs
2002a
Thymic atrophy,
reduced

serum HDLP,
cholesterol,
triiodot-
yhronine,

total bilirubin
LOEL (m/f) = 0.03
mg.kg-1 bw/d
14.5 mg.L-119800 (19.8
µg.g-1)
100198377019.04

2 Generation- rat-F0
dosing 0.1, 0.4, 1.6, 3.2
mg.kg-1 bw/d; oral

gavage males: from
6 weeks before, to
end of mating.
  females: from 6 weeks
before mating through
to the 21st day of
lactation (DL21).

F1:  0.1, 0.4 mg.
kg-1 bw/d; oral
gavage males: from
22 days after birth

to the end of mating
(started 90 days after birth).
  females: from 22 days
after birth through to
DL 21 (for F2).

  

Argus Research Lab 2000 #418-008 (also cited as US EPA OPPT AR-226 0569)  F0 males: reduced body weight gainsF0 male: 
NOEL = 0.1 mg.
kg-1 bw/d

LOEL = 0.4 mg.
kg-1 bw/d
10.5 mg.L-1
45.4 mg.L-1
84900 (84.9
µg.g-1)
176000 (176
µg.g-1)
10
40
8490
4400
37700.44
0.85
F0 female:
reduced

body weight gains
during precoh-
abitation

F0 female:
NOEL = 0.4 mg.
kg-1 bw/d

LOEL = 1.6 mg.
kg-1 bw/d

18.9 mg.L-1
82 mg.L-1
58000 (58
µg.g-1)
184000 (184
µg.g-1)
10
40
5800
18400
37700.65
0.2
F1: significantly
reduced litter sizes
and both viability

and lactation indices.
Reductions in
development

including
delayed eye
opening,

surface righting,
pinna
unfolding and air

righting reflex.
 F1:
NOEL = 0.4 mg.
kg-1 bw/d

LOEL = 1.6 mg.
kg-1 bw/d
NA57.6 ppm
70.4 ppm
10
40
5760 (5.76 pm)
1760 (1.75 ppm)
37700.65
2.14
Rat-Oral gavage
42 days precoh-
abitation to day
21 of lactation;
cross fostering

study.  Doses 0
and 1.6 mg.kg-
1 bw/d
Argus Research Lab 2000 #418-014Maternal: LOEL
decrease in body
weight gain,

reduced gestation
time, delivery time
and litter size

Offspring: LOEL
 increased mortality,
reduced body weight,
increased hepatocyte peroxisomes,

increased type
II pneumo
cytes and lamellar
bodies in the lung.
Maternal
LOEL at dose 1.6 mg.kg-1 bw/d
Offspring LOEL
at maternal
dose of 1.6
mg.kg-1 bw/d
(level in liver of

offspring at
this dose was
70.4 µg.g-1= 70400

µg.kg-1 from
study ARL 418-008)
 70400 (70.4 ppm)40176037702.14

a AF of 10 applied for interspecies variability and lab-to-field extrapolation,  multiplicative with generic factor of 10 for extrapolation from LOECto NOEC OR study specific factor of 4 where study information was available.
b EEV is maximum concentration of PFOS in Canadian polar bears, South Hudson Bay

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