EPTC

Endpoint summary

Description of key information

NOAEL = 3 mg/kg bw

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Revised EPA Guidelines for Testing Chemicals Subdivision F, Series 82-1, p 66 ( Nov 1982)

Qualifier:

according to guideline

Guideline:

EPA OPP 82-1 (90-Day Oral Toxicity)

Version / remarks:

1982 November

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Principles of method if other than guideline:

See it in the full study report. This method is equivalent or similar to OECD 408.

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

CD-Crl:CD(SD)BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

One temperature- and humidity-controlled room (No. 315) was assigned solely
~h~s study. The room had ¯ temperature of 72"F ~30, a relative humidity of
50X ~20~, and a m~namum of 10 changes per hour of filtered 100Z outside ear.
The room mes kept on a 12-hour light/12-hour dark cycle. Temperature and
humidity were monitored continuously by a J¢/80 computer system (Johnson
Controls, Hadison, Wisconsin), and variations from prescribed environmental
conditions were documented.
Animal husbandry and housing at HLA complied with those in the ILAR "Guide for
the ’’3 Care and Use of Laboratory Anamals.
The animals were housed individually in stainless steel screen-bottom cages
(7 in. x ~ an. x 9 3/A an.; s maximum of 60 cages an each rack) with absorbent
paper l~ners in the urine- and feces-collectang pans. The pan l~ners were
changed at least twice ~eekly, and enamels were transferred to clean cages
every 2 weeks. The racks were reposlt~oned wath~n the enamel room weekly to
m~nim~ze the effects of envtroumental variations. Care was ~aken to ensure
that the animals were not dasturbed for reasons other than data collec~aon and
routine maintenance.
Feed was provided ad llbitum from glass ~ars that liner spillage and allowed
easy inspection of the amount and cond~taon of the feed. Water, partially
demineralized by reverse osmosis and sterahzed by ultreviolet l~ght, was
provlded ad llbi~um from an automatic water system (Systems Eng~neerang, Palo
Alto,Calaf~’e’orn~--"~a--~-----a ¯ HLA analyzessamplesof the waterquarterlyfor total
dissolved solids, conductivity, microbiological content, and selected elements
(e.g., heavy metals), organophosphates, and chlorlne~ed hydrocarbons.

Route of administration:

oral: feed

Details on route of administration:

Since humans could be exposed to the test material by the oral route as auunintentional food addztave, EPTC was admanistered to the test animals in
their basal diet.
Disc Prepara~io~
Based on estimated body welshes add feed coosumptio~s chrous~ study
termination, doses were calculated weekly and diets were prepared us sooner
Cheo Friday to be fed so Mooday of the follo~us creatmeoc week. The
appropriate amouoC of EPTC Technical wee brought up to 1% total weighs of
diet wish coru oil, sod theu edu~xed wish the basal disc co ac~eive toe proper
conceu~ra~£ou £0 ~he
~1 die= prepara~ equ~p~uC yes c~eaued before sod ag~er each =~x~.
~epared d~e~s ~ere s~ored regrtsera~ed tu sea~ed c~a~uers ~
~hen dished ~usc prior ~o geedtn$.

Vehicle:

other: basal diet

Details on oral exposure:

Dosage Levels
F~ve tess diets were fed a__d libtCu_____.~m throughout she study; a oesacive control
diet (basal), and four discs mixed Co provide a daily dose based on S EPTC
Techu£cal per kS body weish~. Dace chroush ~ weeks on cesC iodicaced there
was ooC a "so effect" level to this study with regard Co body weights, and it
appeared the body weisht differesces wo~ld contiaue through termiuacion.
Therefore, she low level (Group 2) ~ms reduced from lq mS/kS ~y ~£gh~
3 mS/kS body vet~hc and she l~£d level (Group 3) ~aa reduced from 36 mS/k
body ~etshc Co ~ m~/k~ body ~e~shc. ~eae c~usea besan ~ch She ~eed
o~ered ~or ~eek 7.
Descr~pcioo
Weeks Weeks 7o13
Control 0 0
level lq 3
Low.oLd level 36 15
l~sh-eLtd level 72 72
H~Sh level 120 120

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Homogeueicy sod stability studies, and assays for dose level ver£fication ~ere
couducced. ~ll assays of test diets for EFrC conceocratiou were doue by PPG.
Samples of the prepared discs were sent by HLA ~o PPG for assay.

Duration of treatment / exposure:

13 week

Frequency of treatment:

continous feeding

Dose / conc.:

0 mg/kg bw/day (nominal)

Remarks:

weeks 1-6 and weeks 7-13

Dose / conc.:

18 mg/kg bw/day (nominal)

Remarks:

weeks 1-6

Dose / conc.:

3 mg/kg bw/day (nominal)

Remarks:

weeks 7-13

Dose / conc.:

36 mg/kg bw/day (nominal)

Remarks:

weeks 1-6

Dose / conc.:

15 mg/kg bw/day (nominal)

Remarks:

weeks 7-13

Dose / conc.:

72 mg/kg bw/day (nominal)

Remarks:

weeks 1-6 and weeks 7-13

Dose / conc.:

120 mg/kg bw/day (nominal)

Remarks:

weeks 1-6 and weeks 7-13

No. of animals per sex per dose:

20

Control animals:

yes, plain diet

Details on study design:

From 16A males and 161 females, animals were ass~Ened aC random co the control
end test groups.
Number
Group Se..~x ,Animal ~umbers ?f.,Animals
1 M C07701-C07720 20
F C07721-C0~?k0 20
2 M C07~kI-C07760 20
F C07761-C07780 20
3 M C07781-C07800 20
F C07801-C07820 20
~ M C07821-C078~0 20
F C07841-C07860 20
5 H CO7861-C07880 20
F C07881-C07900 20
Daily ~reatment
EPTC/kR Body Weight
Control - 0
Control - 0
Low dose - 18/3
Low dose - 18/3
Lo~-’~id dose - 36/15
bov-~id dose - 36/15
Bigh-mid dose - 72
Rzgh-~id dose - 72
High dose - 120
High dose - 120
Additional race of each sex from this shipment were sacrificed prior to study
lnit~atlon for prestudy hematology, blood chemistry, and cholinesterase tests

Positive control:

na

Observations and examinations performed and frequency:

Ancemortem Observations
At least twice daily, all animals were observed for morlbund~ty, death, and
obvious indications of a ~oxlc effect. A~ leas~ once each week, animals were
removed from ~helr cages and carefully examined for behavioral abnormalities
and clinical siSus of toxic or pharmacological effects. Dead animals were
removed i~nediately and their ~iesues preserved wlthout delay. Autolysis 1n
dead animals was minimized by placing them in s refrlgeracor uncil ~he
necropsy was started. ~ualifled personnel were available 7 days a week so
tha~ necropsies could be performed on a timely basis and ~xssues promptly
fixed.
p,od~ ~e~hcs and Feed Consumptions
Individual body weights were recorded (end weight gains computed) inlt~ally
and ~hen weekly through 13 weeks. Individual feed consumptions were recorded
weekly through 13 weeks.6
~s Collection S~s~em
The lt~TOX dace acquisition system was used to collect body weight and feed
consumption data and autemortem observations through 13 weeks. ~he system
consists of an electronic balance and a computer microprocessor. Data were
then transmitted to the central co~puter for processing end storage.
Ancemortem observations made for au animal on a day ocher than its routine
observation day were recorded in the bound data book and then entered ~n
~AZTOX on ~he scheduled observation day.
~phthalmxc Examination
Ophthalmic exam%nations were conducted on all animals prior to study
~nit%ation and at term%nat%on by a veterinary ophthalmolo$%st. Animals with
abnormal findings prior to ~n%t%ation of the study were eliminated from
selection procedures.
~llnlcal Pathology
Prior to study initiation, 20 males and 20 females were randomly selected from
the same shipment of animals for collection of prestudy hematology and blood
chemistry data. Ten of each sex were bled (and brain collected) for
chol%nesterase and hematology determinations. The remaining ten of each sex
were bled for electrolyte and blood chemistry determinations.
After 5 weeks on test, 10 animals w~re randomly selected from survivors in
each test group (total of 100) for hematology determinations. After l~ weeks
on test, chess same animals were bled and urine was collected for hematology,
blood chemistry, urinalysis, and chol~nesterase deCerm%net~ous. Animals
scheduled for clinical tests were placed ~n stainless steel metabolism cages
and fasted overnight (water was provided a.~d llbltu.~.__~m). Urine was collected
containers surrounded by ice. Anesthetized rats were bled from the orbital
The following hematology tests were done at pretest and agCer 6 and 1~ weeks.
00000000
Total erythrocyte count (and indices)
ttemoglobin content
Pla~elet count
Total leukocyte coun~
Differential leukocyte count (relative and absolute)
Re~iculocyte count (when signs of anemia were present)
Prothromb~n time
The follow%n~ determlnat%ous o£ chol%nesterase ecE%v%ty were made.
o In plasma, red blood cell, and braxn at prestudy and after 13 weeks.¯ he follo~ng blood chemisCry tests were done e~ pres~udy and e~ter 13 ~eeks
(listed in order of priority if the sample was limited):
ooooooooooooooo
Alanine aminotransferase (ALT)
Alkaline phospha~ase (Alk Phos)
Urea hi,roBert (UN)
k~par~ate am~notransferase
Glucose (GLU)
Direc~ end total bil~rub~n (D and T SILl)
Total pro~e~n (T PRO)
Album%n (ALB)
A/G ratio
Clobul%n
Lactate dehyrogenase (LDH)
Total cholesterol (CHOL)
Calcium (CA)
Sodium
Potassium
The followinB urznalysis determinations were done after 13 weeks:
o Volume end appearance
o p~
o Blood
o Protein
o Bil~rubin
o Glucose
o Urobil~nogen
o Specific gravity
o M~¢roscop~c examination of sedimen

Sacrifice and pathology:

Necropsy:
The 40 an%male used for prescudy cl%n%cal determinations were sacrificed end
discarded after blood collection and removal of brain for cholines~erase
determination. All other enizmls placed on test, reBerdleas of their fate,
were subjected to ¯ Bross pos~mor~e~ examination (necropsy) and tissue
The necropsy included examination of ~he external surface, all ortfices, the
cranial cavity, carcass~ the external and cut surfaces Of the brain, spinal
cord, the nasal cavity and paranaaal slnuees, and the abdominal, ~horac~c~ and
pelvic cavities and their v~scera.
The follow%ng eissues and orBans were examined Brossly then preserved %n 10%
phosphate-buffered formalin.8
All gross lesions
Adrenal glands
Aorta
Bone with marrow (femur rich
articular surfaces, and sternum)
Brain (sections included medulla,
pons, cerebral cortex~ and
cerebellar cortex)
Cecum
Cervix
Colon
Duodenum
Ep~d~dy~des
Esophagus
Exorb~tal lacrimal gland
Eyes*
Heart
ileum
Jejunum
K~dneys
Liver
Lunge
Lymph nodes (submandibular and
Mae---ry gland and skin
Muscle (skeletal, posterior to
femur including sciatic nerve)
Ovaries
Parathyroid glands
Peripheral nerve
Pituitary
Prostate
Salivary glands
Seminal vesicles
Skin
Spleen
Spinal cord (three sections:
cervical, mid-thoracic, lumbar)
Stomach
Testes
Thb~us
Thyroid glands
Trachea
Urinary bladder
Uterus
Vagina
~ixed ~u Zenker~s solution at scheduled
I~ addition to te~-m~nal body ve~Kht, the heart, l~ver, kidneys, spleen,
and gonads from animals sacrificed after l~ reeks, vere ve~ghed. Pa~red
organs ~e~e ve~ghed separately.
.Hts~o~atholoRy
The following fo~malin-f~xed C£ssues vere examined mzcroscopically:
All tissues from all animals in the control, high-dose, and
h~gh-m~d-dose groups that d~ed on test or were sacrificed after
l~ reeks.
Spleen, l~ver, k~dneys, hearts, and gross les~ons from all low- and
lo~-m~d-dose animals thac ~ere sacrlf~ced a£te~ 1~ ~eeks.

Statistics:

Statistical Analys~s
Body weight, feed consumption, organ weight, the rac~o of organ weight co body
weight, b~ood chemistry, and hematology da~a were analyzed separately for each
sex. Differences were considered s~a~s~cally s~gn~f~can~ a~ p~ 0.05.~hen the group means differed significantly by analysis of variance, & then
Dunnett’s t-test 5 was used to compare the treatment means with the control
mean. Chi square analysis was used to compare nouperametric data such as
urine multistik data.

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

~ntemor~em Observations
Table Z
No ~rea~men~orelated aflte~ortem observations were observed for anin~als Tn any
of ~he dose levels. Inciden~al obset’va~ione normally found in a colony of
rats ~his size were observed throughou~ the ~reat~enc period. Frequen~
observations included alopecLI, ~h~n hair coats, ~alocclusione, skin lesions,
and scab fot-~aCions involving the £agsed ear, red and/or swollen ears, and
lacr~Jaatiou.

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

~dy. Wei~h~ and Cumulative BodzWe£~ht Gains
Hales: Tables ~ and 5; Figures 1 and 2
Females: Tables 6 and 7; Figures 3 and ~
There was a dose-related decrease ~n mea~ body weTghcs for ~ales and females
receiving 36/i~, 72, and 120 mg/k$ beginning at Week i for ma~es and Week
~or reales. The differences were statistically significant through .
termination. Cu~ulattve weight gains were also dose rela~ed and
d~fereut chroush ~e~uination. For the lS/3"~g ~ales, body weTgh~s were
s~ig~caucl~ lower ~han control wet~a ~rom Wee~ ~ ~hro~Kh 12, and
¢u~la¢~ve ~aim~ ~rom Week Z Through L2. C=~iacTve ~ains ~or ~8/3~
were s~nig~can~y lower ~or Weeks ~ ~hrou~h ~Z, bu~ ~ean body we~s were
only sporadically significantly dTgfereu: durin~ :h~s petTed. ~or bo~h
and fe~les receTv~n~ tS/~ mK/kK, ~here were no s~lftcan~ d¢~erences
we¢~hTs or wei~h~ ~ains a~ Week
Hales and females created with 120 and 72 mg EPTC/k~ BW had mean body weights
that were lees =han 90¢ of ~he controls. Their cumulative body weight Keens
were less chart 85¢.
¯ nx~als treated with 36/15 mg/kg had mean body weig.ts approxx~ately 90~ of
controls and weight gainl 85I to 90I of con~rele.
~imale ~rea~ed with 18/3 mg/kg had body we~hcs and we~&ht gains 90~ co
oE controls.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Fee,d Cons,mapt~on
There were no d~f£ereuces £n feed cons"~p~ous for an~als receiving
18/3 mg/kg and ~he controls. Reduced feed cousumptious~ especially
were observed in the 120- end ?2-~g/kg groups when compared to the control
groups. There was a trend for reduced feed consumption ~n animals receiving
36/1~ m~/kg, b~ ~he d~f~ere~ces were generally no~ s~a~s~ically
a~et dose level reduction.

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Opbthalmoscop£7 Examination
Table ]
Annals with abnocmal ophthalmic lesions were excluded ~rom ~he pool og
animals used for this study. Ophthalmic les¢one observed Tn animals prior co
study Cer~na£ion were sporadic and did not appear related to ~rea~men~. ~ey
consisted of ocular discharges, phthisis bulb~, ec~opic pupil, and choroidal
atrophy and suepec~ choroTdal atrophy.

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Hematology page 11 on paper

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Clinical ChemlsCr~
Tables 12 and 1~
¯here were no effects apparenC ~n cl~nxcal chemistry value8 for
recexv~ng ~/1~ or 15/3
$~gn~f~ca~tly h~gher asparcate am~noCrausferase ~AST) levels were observed
both ~ales and ~e~ales treaced wi~h 72 and 120 mg/kg EI~C than ~u the
concrols. ~ne ~ncreased AST levels were probably rela~ed to the chronic
m~ocardtcxs obset-ved m~croscop~cally ~n these two groups.
Other dose-related changes observed £n clinical chemistry data for an~ls
treated with 72 and 120 mg/kg ~ucluded increased urea nitrogen values ~ln
males and females), and decreased glucose values ~tn females only).

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Ur~nalTs~s
Table 14
Urine spec~txc gravity was greater and urt.e vol’~e yes less for
treated ~th 72 and 120 ~/kg. The ~ncldence of urinary ketone ~Append~x
x~ ~e~alee treated w~th 72 a~d 120 ma/kg was grea~er than tha~ of ~he
controls and was pro~a~ly rela~ed to their decreased glucose val~es.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Organ weights
A~solute Weights: Table 16
Relative Weights: Table 17
A dose-related decrease in terminal body we%ghts was noted for males end
females created with ~6/15, ~2, and 120 mg/kg ~W. Differences ~n absolute
and/or relative heart, bra~n, testes, and spleen weights were related Co c~ese
d~ffereuces in terminal body ~etghcs.
~elat~ve and/or absolute liver weights were increased in the 72- and 120"~g/kg
males and females. ~elaC~ve ktduey weights also a~peared ~ncreased. For both
lzver and k~dney, the d~£ferences ~ere more pronounced ~n females.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Anatom.~,calPatholoRy
Tables 18, 19, and 20
There was an increase in the incidence of accentuated lobular pattern
livers of 120-~ng/kg anxmals and d~ffusely light livers in l~O-qug/kg females.
There ~as no treatment-related liver htstopatholog~, however.
~o ocher gross lesions observed at necrospy could be related to treatment
EPTC.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Treatment-related h~stopaChology yes seen in the heart. O~her les~ons ~ere
typical for Sprague-Davley rats of this age, and were considered incidental co
the study.
Treatment-related card~omyopaChzes were characterized as chronic
~rhlch varied from mzn~mal co mild. There ~as a ~ocal co mulC~ocal myocardial
degeneracLou, ~n~1CraC~ng mououuclear cells, g~broplas~a, and occasional
~acCy changes. ~e ~ucldeuces aretcabled

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Description (incidence and severity):

Chollnesterase Data: Important
Table l5
Females treated w~Ch 120 mg/kg had a mean brain cholinesCerase value which was
86Z of the controls, and the difference was staCisClcally s~gnif~canc. ~ales
created w~ch 72 and 120 mg/kg had mean plasma cholinesterase values which were
87Z of the control, but the d~fferences were noC sCaCistlcally significant.
All other mean chol~nesterase values were greater than 89Z of the control
value and not considered biologically ;mportauC.
T~e red cell and plasma chollnesCerase values for females were higher than
chose for males; however, ~h~s yes au expected response thaC ~s normal for
female Sprague-Davley rats

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 3 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

15 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

15 mg/kg bw/day (nominal)

System:

cardiovascular

Organ:

heart

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

NOAEL = 3 mg/kg bw based on the observed increase of liver weights and myocardial degeneration at dose levels of 36/15 mg EPTC / kg bw or higher.

Executive summary:

NOAEL = 3 mg/kg bw based on the observed increase of liver weights and myocardial degeneration at dose levels of  36/15 mg EPTC / kg bw or higher.

+ Summary on page 10 at computer

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

3 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

reliable 1

Organ:

heart

liver

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available