resorcinol; 1,3-benzenediol

Repeated dose toxicity: oral

Administrative data

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:

other: Guideline Study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

The study was designed to comply with OECD Guideline No. 408, 21 September 1998.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Resorcinol

EC Number:

203-585-2

EC Name:

Resorcinol

Cas Number:

108-46-3

Molecular formula:

C6H6O2

IUPAC Name:

resorcinol

Details on test material:

Resorcinol (AO11), >95% purity

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: purified water

Duration of treatment / exposure:

Three treated groups of 10 male and 10 female Sprague-Dawley rats received the test item, Resorcinol (A011), (batch No. 706030517), daily by
gavage at 40, 80 or 250 mg/kg/day for 13 weeks. An additional group of 10 males and 10 females received only the vehicle (purified water) and actedas a control group. At 0 and 250 mg/kg/day (groups 1 and 4), six animals of each sex were treated for 13 weeks and then kept for a 4-week
treatment-free period. Six animals of each sex in groups 2, 3 and 4 were used for toxicokinetic investigations.

Frequency of treatment:

Daily for 13 weeks

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 40, 80 and 250 mg/kg/day
Basis:
other:

No. of animals per sex per dose:

Three treated groups of 10 male and 10 female Sprague-Dawley rats received the test item. An additional group of 10 males and 10 females
received only the vehicle (purified water) and acted as a control group.

Examinations

Observations and examinations performed and frequency:

The animals were checked daily for mortality and clinical signs. Detailed clinical observations were carried out weekly, and a Functional Observation
Battery (including motor activity) was performed at the end of the treatment period. Detailed observations included (but were not limited to) changes
in the skin, fur, eyes, mucous membranes, occurrence of secretions and excretions and autonomic activity (e.g. lachrymation, piloerection, pupil size,
unusual respiratory pattern). Changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypes
(e.g. excessive grooming, repetitive circling) or bizarre behavior (e.g. self-mutilation, walking backwards) were also recorded. In the functional
observation battery the following parameters were assessed and graded: "touch escape" or ease of removal from the cage, in the hand: fur
appearance, salivation, lachrymation, piloerection, exophthalmia, reactivity to handling, pupil size (presence of myosis or mydriasis), in the standard arena (two-minute recording): grooming, palpebral closure, defecation, and urination counts, tremors, twitches, convulsions, gait, arousal (hypo-
and hyper-activity), posture, stereotypic behaviour and breathing, ataxia, hypotonia. In addition, the following parameters, reflexes and responses
were recorded: touch response, forelimb grip strength, pupil reflex, visual stimulus, auditory startle reflex, tail pinch response, righting reflex,
landing foot splay, at the end of observation: rectal temperature.

The motor activity of each animal was also measured by automated infra-red sensor equipment over a 1-hour period.

Sacrifice and pathology:

On completion of the treatment period and after the treatment-free period, the animals were sacrificed and submitted to a complete macroscopic
post-mortem examination. Designated organs (see list below) were weighed and selected tissue specimens were preserved. A microscopic
examination was performed on selected tissues.

The following organs and/or tissues were evaluated: Adrenals, Aorta, Brain (including medulla/pons cerebellar and cerebral cortex), Cecum, Colon, Duodenum, Epididymides, Esophagus, Eyes with Harderian glands, Femoral bone with articulation, Heart, Ileum (with Peyer patches),Jejunum,
Kidneys, Liver, Lungs with bronchi, Lymph nodes (mandibular and mesenteric), Mammary glands/area, Ovaries (including oviducts), Pancreas,
Pituitary gland, Prostate, Rectum, Salivary glands (sublingual and submandibular), Sciatic nerve, Seminal vesicles (including coagulation gland),
Skeletal muscle, Skin, Spinal cord (cervical, thoracic and lumbar), Spleen, Sternum with bone marrow, Stomach with forestomach, Testes, Thymus,
Thyroids with parathyroids, Tongue, Trachea, Ureters, Urinary bladder, Uterus (horns and cervix) and Vagina. Macroscopic and microscopic
evaluations were perfomed on all above organs/tissues with the following above organs/tissues not receiving a microscopic evaluation:
skeletal muscle, tongue and ureters.

Other examinations:

Body weight and food consumption were recorded weekly. Ophthalmological examinations were performed before the beginning of the treatment
period on all animals and at the end of the treatment period for control and high dose-group animals. Hematological and blood biochemical
investigations were performed at the end of the treatment period and at the end of the treatment-free period. Urine parameters were investigated at
the end of the treatment period.

Venous blood (approximately 0.5 mL) was taken from the orbital sinus of the animals under light isoflurane anesthesia into a tube containing lithium heparin. The blood was centrifuged, and the plasma was kept frozen in individual tubes at -20°C until analysis after the development and validation ofthe analytical method.

Satellite animals were checked for clinical signs and mortality. Body weight was recorded for dosing purposes only. The data were filed and are
presented separately from those of the principal animals in the study report. No necrospy was performed.

Statistics:

Statistical analysis were peformed using the followng tests when appropriate: Kolmogorov-Lilliefors test, Dunn test, Mann-Whitney/Wilcoxon test,
Student test, Bartlet test and Fischer test.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

Under the experimental conditions of the study, the No Observed Adverse Effect Level (NOAEL) was 80 mg/kg/day in both sexes.

FOB: Examination of the animals during the Functional Observation Battery did not reveal any treatment-related effect.

Mortalities and clinical observations:
Two males out of 20 total animals receiving 80 mg/kg/day were found dead, one on day 48 and another on day 85. Both males experienced
convulsions before death and one male also had excessive salivation. One female out of 20 total animals receiving 250 mg/kg/day was found dead onday 35 (week 5) of treatment. No clinical observations were recorded for this animal prior to death. At necropsy, foamy content was noted in the lungs in one animal and in the lungs and trachea of two animals. At microscopy, the major findings were alveolar hemorrhage in the lungs of one animal;
moderate alveolar emphysema in the lungs of one animal; and slight alveolar edema in the lungs of one animal. The lung lesions might be a
contributing factor to these mortalities, in relation with highly probable misdosings. Taking into consideration that there were no mortalities in the
male rats given the higher dose-level (250 mg/kg/day) and that observed deaths were probably caused by gavage errors, the above mentioned
mortalities were considered to be accidental and not to be treatment-related. Therefore, no treatment-related deaths were noted during the study
and the animals found dead died as a consequence of misdosing.

The majority of animals given 250 mg/kg/day experienced intermittent convulsive movements and excessive salivation from around week 7 until the end of the dosing period. Two males had loud breathing, one during week 6 and the other between weeks 11 and 13. No clinical observations
considered to be related to treatment were noted after the cessation of treatment. With the exception of the two males which had convulsions and
died (probable misdosings), no clinical observations were recorded at 80 mg/kg/day.

One male receiving 40 mg/kg/day had a round back, partially closed eyes and an emaciated appearance during weeks 11 and 12, a piloerection
during weeks 11 and 13, associated with a marked body weight loss and a slightly lower food consumption. As these clinical signs were observed in
isolated animals and not noted at higher doses (80 or 250 mg/kg/day), they were considered to be incidental and not test item-related. One satellite male given 40 mg/kg/day had dyspnea and loud breathing during weeks 11 and 12, associated with a marked body weight loss, an emaciated
appearance and regurgitation during week 12 of treatment. These events were considered to be related to an abnormal growth of teeth noted in this
animal, and were not considered to be treatment-related. Body weight and body weight gain: There were no effects on group mean male body weight during either the treatment or treatment-free periods. Females receiving 250 mg/kg/day gained slightly less weight than the controls in weeks 4 to
8 of treatment. During week 11, mean body weight decreased (-3g) in males receiving 40 mg/kg/day. This was mainly due to one animal
(E27368, -93 g during this period) having abnormal teeth growth and therefore was not considered to be treatment-related.

The female group receiving 250 mg/kg/day gained only 37g versus 43g in controls (ie 86% of the weight gained by the controls) from week 4 to week 8. With this exception, body weight changes of females were similar in treated and control groups. The recovery group of males receiving
250 mg/kg/day consistently weighed statistically and significantly more than the recovery control males during the last third of the dosing period
and during the post-treatment period. However, generally the control recovery males weighed slightly less than the principal control males so this
was considered not to be related to treatment.

The recovery group of females receiving 250 mg/kg/day also weighed significantly more than the recovery control females over weeks 1 to 13 of
dosing. There was no difference in body weight between the recovery group of females treated at 250 mg/kg/day and the principal control females,
so the statistically significant increase in body weight was not considered to be toxicologically significant. The recovery group of females treated at
250 mg/kg/day continued to weight more than the recovery control females for the duration of the treatment and post-treatment periods, although body weight gains were comparable between the two groups.

Food consumption: There were no effects of treatment on group mean male or female food consumption. During the treatment-free period, males and female at 250 mg/kg/day consumed slightly more food than the controls.

Functional Observation Battery and motor activity: There were no effects of treatment on forelimb grip strength, landing foot splay, rectal
temperature, pupil size, reactivity to handling, defecation or urination. Motor activity was not affected by the treatment either.

Hematology and blood biochemistry: No differences of toxicological importance were noted between treated and control animals in any of the
parameters examined.

Urinalysis: No treatment-related effects on the qualitative or quantitative urine parameters investigated were noted.

Organ weight: No treatment-related effects on organ weights were noted.

Necropsy findings and histopathological examination: No treatment-related necropsy findings were noted and no changes that were considered to
be related to treatment were seen at microscopic examination.

Effect levels

Dose descriptor:

NOAEL

Effect level:

80 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the experimental conditions of the study, the No Observed Adverse Effect Level (NOAEL) was 80 mg/kg/day in both sexes.

FOB: Examination of the animals during the Functional Observation Battery did not reveal any treatment-related effect.