1,3-dioxolane

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report Date:

1991

Materials and methods

Test guideline

Qualifier:

equivalent or similar to

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)

Deviations:

yes

Remarks:

See below for a description of deviations from OECD 407

GLP compliance:

yes

Limit test:

no

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): 1,3-dioxolane
- Analytical purity: 99.9% (statement)
- Lot/batch No.: UN 1166
- Other: No reference standard was available. The test substance was therefore characterised by : IR analysis and comparison of the maxima with those of a reference spectrum; GC/FID analysis showing on impurity (0.7%);TLC (development with iodine), only one spot detected.

Test animals

Species:

rat

Strain:

other: Sprague Dawley Crl:CD® (SD)BR

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
Note: for most of the aspects below the study report referred to the protocol.
- Source: Charles River Breeding Laboratories, Inc., Raleigh, North Carolina, USA
- Age at study initiation: protocol stated: age at receipt at least 42 days
- Weight at study initiation: protocol stated: at receipt expected to weigh 151-175 g
- Fasting period before study: none stated in protocol
- Housing: protocol stated: individually housed
- Diet (e.g. ad libitum): protocol stated: ad libitum Purina rodent chow
- Water (e.g. ad libitum): protocol stated: ad libitum
- Acclimation period: protocol stated: rats will be acclimated (duration not specified)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): protocol stated: targeted 70-78°F (equivalent to 21-26°C).
- Humidity (%):protocol stated: targeted 35-65%
- Air changes (per hr): protocol stated: 10 changes per hour
- Photoperiod (hrs dark / hrs light): protocol stated: fluorescent light, 12 hours light, 12 hours dark

IN-LIFE DATES: From: October 31, 1989 To: November 15, 1989

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: one control group received the vehicle corn oil, another control group was given water

Details on oral exposure:

VEHICLE
- Justification for use and choice of vehicle (if other than water): not provided
- Concentration in vehicle: not reported
- Amount of vehicle (if gavage): the dose volume was 5 mL/kg bw, adjusted daily on the basis of the individual body weights.
- Lot/batch no. (if required): not reported
- Purity: not reported (Mazola® corn oil was used)

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

Daily oral dosing by gavage for 14 days. Dose levels were 75, 250, 750 and 2000 mg/kg bw/day.

Frequency of treatment:

Once daily.

No. of animals per sex per dose:

10 males and 10 females per group

Control animals:

other: one control group received the vehicle corn oil, another control group was given water

Details on study design:

The study was performed in agreement with OECD 407 (1981), with the following deviations:
(1) No clinical biochemistry was performed. This is considered to be a minor deviation. Significant alterations of clinical biochemistry parameters are usually associated with microscopic findings. The NOAEL is rarely based on a parameter from clinical biochemistry alone. Microscopic examination of the major organs was performed during this study.
(2) The list of organs examined microscopically was incomplete (heart not examined).
(3) Haematology: no measurement of blood clotting potential.
The study was also performed in agreement with OECD 407 (1995), with the following deviations:
(1) No clinical biochemistry was performed. This is considered to be a minor deviation. Significant alterations of clinical biochemistry parameters are usually associated with microscopic findings. The NOAEL is rarely based on a parameter from clinical biochemistry alone. Microscopic examination of the major organs was performed during this study.
(2) The list of organs examined microscopically was incomplete. Not examined were: brain, spinal chord, stomach, small and large intestine, heart, thyroid, trachea, urinary bladder, lymph nodes, peripheral nerve, bone marrow.
(3) Haematology: no measurement of blood clotting potential.
(4) No justification was given for a 14-day instead of 28-day study duration. The study was intended to be a range-finder for a developmental toxicity study and a 14-day duration for a range-finder is not uncommon.
(5) Brain and heart were not weighed at termination.
(6) No detailed investigation of sensory reactivity to stimuli.

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations checked in table were included.
DETAILED CLINICAL OBSERVATIONS: No data
BODY WEIGHT: Yes
- Time schedule for examinations: daily.
FOOD CONSUMPTION: weekly
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No
OPHTHALMOSCOPIC EXAMINATION: No
HAEMATOLOGY: Yes
- Time schedule for collection of blood: sacrifice
- Anaesthetic used for blood collection: Yes (anaesthetic not identified)
- Animals fasted: No
- How many animals: all surviving animals
- Parameters checked in table were examined.
CLINICAL CHEMISTRY: No
URINALYSIS: No
NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (weighing of liver, kidneys, adrenals, spleen, pancreas, lungs, pituitary, thymus, testes, epididymimes, seminal vesicles, ovaries, uterus)
HISTOPATHOLOGY: Yes (from controls and high dose: adrenal glands, kidneys, liver, lungs, pancreas, pituitary, spleen, thymus, testes, epididymides, prostate, seminal vesicles, coagulating gland, ovaries, uterus; tissues and organs from intermediate doses were analysed in case there were treatment related findings at the high dose)

Statistics:

All body weight, feed consumption and organ weight data were statistically compared against both control groups using the following statistical tests: analysis of variance, Dunnett’s test, Bartlett’s test of homogeneity, Kruskall-Wallis test and Dunn’s test. Analysis of variance followed by Dunnett’s t-test was performed on the haematological data. Significance was tested at the 5% and 1% level.

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):

effects observed, treatment-related

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

The results are summarised in the Table under “Remarks on results including tables and figures”. The changes are represented either as percentage change relative to the control (e..g -35 = 35% reduction, +10 = 10% increase) or as incidence (e.g. 3/10 represents 3 out of 10 rats). Empty cells mean that no effect was seen for that group. In the study two control groups were used (water and corn oil). Percentage differences in the table were with respect to the corn oil control. Where a dose relationship was observed, this is indicated in the last column.
Under the table with findings, a discussion of the study results is provided and the NOAEL is derived.

Effect levels

Dose descriptor:

NOAEL

Effect level:

75 mg/kg bw/day (nominal)

Sex:

male

Basis for effect level:

other: reduced body weight gain and reduced platelet count

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Study results in Table form.

Dose (mg/kg bw/day)	0	0	75	75	250	250	750	750	2000	2000	DR
Sex	m	f	m	f	m	f	m	f	m	f
Mortality									3/10	4/10
Clinical signs^(A)								+	+	+
Body weight									-20#	-10#^(B)
Body weight gain
day 1-8					-6	-40	-28	-51	-202	-217	M&F
day 1-15					-11		-23		-127	-88	M
Food consumption							-12		-40	-12	M
Haematology
platelets					-12		-27#		-50#	-36#	M
% reticulocytes						-63#			-74
leukocytes						-21		-27		-39	F
lymphocytes						-52#		-43#		-72#
nucleated RBC										-62
Organ weight
liver							+11(r)#		+31(r)#	+13(r)	M
testes									+20(r)
left epididymides									+19(r)
right epididymides									+19(r)#
seminal vesicles with       fluid									+32(r)#
seminal vesicles   without fluid									+23(r)#
prostate									-27(a)#
kidney									-13(a) +9(r)	+11(r)
spleen							-8(a)	-16(a)# -17(r)#	-31(a)# -16(r)	-35(a)# -30(r)#	M&F
pancreas										-29(a) -25(r)
thymus								-13(a) -15(r)	-49(a)# -36(r)#	-35(a) -35(r)	F
lungs							+14(r)		+16(r)
pituitary								+44(a)# +45(r)
Pathology
Macroscopy
Decedents
gastric erosion									1/10
reddened area in stomach									1/10
Survivors	no treatment related findings
Microscopy
kidney
- multifocal basophilia cortical tubules									3/10
- intratubular crystals									2/10
- multifocal tubular dilatation									3/10
- chronic pyelitis									2/10	2/10
liver
- hepatocellular centrilobular hypertrophy									6/10	2/10
- hepatocellular midzonal vacuolation									6/10	3/10
testes
- testicular degeneration									2/10
- multinucleated cells									2/10
thymus: atrophy									5/10	3/10

Note :    Percentage differences in the above table were with respect to the corn oil control.

DR          dose related

#             Statistically significant difference from corn oil control at 5% level or below

(a)/(r)     absolute/relative organ weight

+             Clinical signs were observed

(A)          Clinical signs observed were excess salivation (750 and 2000 mg/kg), and hypotonia, ataxia, decreased motor activity, impaired and loss of righting reflex, gasping, bradypnea, laboured breathing, oral exudates, rales, lacrimation, red penile exudates, urine stained abdominal fur.

(B)          Statistically significant only between day 3 and 9, final body weight was 6.6% lower than that of the corn oil control.

The following findings are considered unrelated to the treatment:

·        changes in percentage reticulotytes (no dose relationship (F); for females at 2000 mg/kg a change of +72% was recorded relative to the water control, hence change of -74% in males relative to corn oil control considered to be dubious);

·         increased relative liver weights (no changes in absolute liver weight; for males at 750 mg/kg, statistical significance only relative to corn oil control, not relative to water control; at 2000 mg/kg the increases in relative liver weight were likely to be related to the lower terminal body weight);

·        increased relative weights of testes, epididymides and seminal vesicles (attributable to reduced body weight);

·        decreased absolute prostate weight (attributable to reduced body weight, relative prostate weights were unchanged relative to controls);

·        changes in kidney weight (no change of absolute kidney weight of females, increase of relative kidney weight of females attributable to reduced final body weight; in males the reduction of the absolute kidney weight was small (13%), not accompanied by a reduction of relative kidney weight and probably attributable to the lower final body weight);

·        reductions of absolute and relative pancreas weight in females at 2000 mg/kg: the changes in both parameters were 25-29% relative to the corn oil control (but not statistically significant), but only 10-15% relative to the water control, the reductions are probably attributable to the lower final body weight);

·        increased relative lung weights for males at 750 and 2000 mg/kg (no changes in absolute weight, no dose relationship, reduction at highest dose probably related to reduced final body weight);

·        increased absolute and relative pituitary weight in females at 750 mg/kg (no similar effect at the highest dose).

 

Adverse treatment related changes were: mortality at 2000 mg/kg (M & F); clinical signs at 750 mg/kg (F) and 2000 mg/kg (M and F); reduced body weight at 2000 mg/kg (M & F); reduced body weight gain at 250-2000 mg/kg (M) and at 2000 mg/kg (F); reduced food consumption at 750 mg/kg (M) and 2000 mg/kg (M and F); reduced platelet count at 250 and 750 mg/kg (M) and 2000 mg/kg (M and F); reduced leukocyte count caused by reduced lymphocyte count at 250-2000 mg/kg (F); reduced nucleated RBCs (F, 2000 mg/kg); reduced absolute spleen weights at 750 mg/kg (M) and reduced absolute and relative spleen weights at 750 mg/kg (F) and at 2000 mg/kg (M and F); reduced absolute and relative thymus weights at 750 mg/kg (F) and at 2000 mg/kg (M and F), and thymus atrophy observed microscopically at 2000 mg/kg (M and F); gastric erosion and local irritant effects on stomach lining apparent as reddened areas in the stomach in one male at 2000 mg/kg; kidney toxicity at 2000 mg/kg (multifocal basophilia of the cortical tubules, multifocal tubular dilatation and intratubular crystals in males, chronic pyelitis in males and females); liver toxicity at 2000 mg/kg (M and F): hepatocellular centrilobular hypertrophy and hepatocellular midzonal vaculation); testicular degeneration in males at 2000 mg/kg.

 

Based on reduced body weight gain in males and females, reduced leukocyte and lymphocyte count in females, and reduced platelet count in males, all at 250 mg/kg, the NOAEL is 75 mg/kg bw/day.

Applicant's summary and conclusion

Conclusions:

NOAEL 75 mg/kg bw/day, LOAEL 250 mg/kg bw/day.

Executive summary:

A 14-day repeated dose oral toxicity study on 1,3-dioxolane was performed in Crl:CD® (SD)BR Sprague-Dawley rats according to OECD 407 (1981) at dose levels of 75, 250, 750 and 2000 mg/kg bw/day (10 males and 10 females per dose). The test material was administered in corn oil (dose volume 5 mL/kg). Corn oil controls were included, as well as controls which received water. Observations on toxicological signs and body weight measurements were made daily, food consumption was measured on a weekly basis. Haematalogy was performed on blood collected just prior to sacrifice. Necropsy was performed on all animals. Organs weights of liver, kidneys, adrenals, spleen, pancreas, lungs, pituitary, thymus, testes, epididymides, seminal vesicles, ovaries and uterus were measured at sacrifice. Microscopic examination was performed on the following organs and tissues of controls and high dose animals: adrenal glands, kidneys, liver, lungs, pancreas, pituitary, spleen, thymus, testes, epididymides, prostate, seminal vesicles, coagulating gland, ovaries, uterus; tissues and organs from intermediate doses were analysed in case there were treatment related findings at the high dose.

Gastric erosion and local irritant effects on stomach lining apparent as reddened areas in the stomach observed in one male at 2000 mg/kg was considered to be incidental, due to the treatment by gavage.

Adverse treatment related changes were: mortality at 2000 mg/kg (M & F); clinical signs at 750 mg/kg (F) and 2000 mg/kg (M and F); reduced body weight at 2000 mg/kg (M & F); reduced body weight gain at 250-2000 mg/kg (M) and at 2000 mg/kg (F); reduced food consumption at 750 mg/kg (M) and 2000 mg/kg (M and F); reduced platelet count at 250 and 750 mg/kg (M) and 2000 mg/kg (M and F); reduced leukocyte count caused by reduced lymphocyte count at 250-2000 mg/kg (F); reduced nucleated RBCs (F, 2000 mg/kg); reduced absolute spleen weights at 750 mg/kg (M) and reduced absolute and relative spleen weights at 750 mg/kg (F) and at 2000 mg/kg (M and F); reduced absolute and relative thymus weights at 750 mg/kg (F) and at 2000 mg/kg (M and F), and thymus atrophy observed microscopically at 2000 mg/kg (M and F); kidney toxicity at 2000 mg/kg (multifocal basophilia of the cortical tubules, multifocal tubular dilatation and intratubular crystals in males, chronic pyelitis in males and females); liver toxicity at 2000 mg/kg (M and F): hepatocellular centrilobular hypertrophy and hepatocellular midzonal vaculation); testicular degeneration in males at 2000 mg/kg.

Based on reduced body weight gain in males and females,reduced leukocyte and lymphocyte count in females,and reduced platelet count in males, all at 250 mg/kg, the NOAEL is 75 mg/kg bw/day.