Registration Dossier

Administrative data

Description of key information

A sub-chronic oral toxicity study (90-day) revealed a NOAEL of 450 mg/kg bw/day, and a LOAEL of 1000 mg/kg bw/day. In one dermal repeated dose toxicity study (21 days) a NOAEL of 360 mg/kg bw/day (highest concentration tested) was obtained with the rabbit. Applying route to route extrapolation, by assuming that penetration of BMDBM through skin is equal to penetration through the intestinal wall, the same effect levels as for oral route shall apply for the dermal route of exposure.

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
Study period:
March - July 1983
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
: no neurobehavioral tests were made, no purity of the test item was reported, 4-week recovery period in the control and high-dose group
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
other: Füllinsdorf Albino-SPF
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Füllinsdorf
- Age at study initiation: 6 - 8 weeks
- Weight at study initiation: 158 - 190 g (males), 130 - 147 g (females)
- Housing: 2 animals per cage
- Diet: NAFAG No. 850, restricted (feeding study)
- Water: ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 45 - 65
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1983-03-08 To: 1983-07-07
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
DIET PREPARATION
- Rate of preparation of diet: The test article was sifted to remove clots and mixed with the rat diet. The mixtures were freshly prepared each week (2.5 kg diet + test article for each male dose group; 2 kg diet + test article for each female dose group).
- Mixing appropriate amounts with: NAFAG No. 850 (pulverized)
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Samples of mixtures for analysis were taken during week 2 and week 13.
Duration of treatment / exposure:
91 - 94 days
Half the animals of the control and of the high-dose group were observed for further 30 days without treatment.
Frequency of treatment:
daily
Dose / conc.:
0 mg/kg bw/day (nominal)
Remarks:
Basis: nominal in diet
Dose / conc.:
200 mg/kg bw/day (nominal)
Remarks:
Basis: nominal in diet
Dose / conc.:
450 mg/kg bw/day (nominal)
Remarks:
Basis: nominal in diet
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Remarks:
Basis: nominal in diet
No. of animals per sex per dose:
12 rats per sex per dose group
Control animals:
yes, plain diet
Details on study design:
- Rationale for animal assignment: random table
- Post-exposure recovery period: 30 days
Positive control:
No positive control substance was used.
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: continuously

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: at week 13
- Dose groups that were examined: only high-dose group (1000 mg/kg bw/day)

HAEMATOLOGY: Yes
- Time schedule for collection of blood: during weeks 2, 6, and 14
- Anaesthetic used for blood collection: Yes (N2O)
- Animals fasted: No data
- How many animals: all
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: during weeks 2, 6, and 14
- Animals fasted: No data
- How many animals: all
- Parameters checked in table 1 were examined.

URINALYSIS: Yes
- Time schedule for collection of urine: during week 5 and 13
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked in table 1 were examined.

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table 2)
HISTOPATHOLOGY: Yes (see table 2)
Statistics:
Results of haematology and blood chemistry:
Dunn test (Technometrics 1964, 6: 241-52):Multiple comparisons, control versus all treated groups. Error rate = 0.1.

Body weights:
Growth rate (Rao, Biometrics 1958, 14: 1-17)
Adjusted organ weights (Trieb et al., Toxicol. Appl. Pharmacol. 1976, 35: 531-42)
Jonckheere test (Biometrika 1954, 41: 133-45)
U-test (Siegel, Monoparametric statistics 1956)
Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
Clinical signs were loss of hair, excitation, and crusted eye. The symptoms were distributed among the test groups as summarised in table 3. With one exception all symptoms had a slight intensity. These symptoms are normally found in animals used fort his study.
They were not considered to be treatment-related.
Mortality:
mortality observed, non-treatment-related
Description (incidence):
Treatment-related deaths did not occur. Two female rats (450 mg/kg/day; 1000 mg/kg/day) died as a result of anaesthesia and taking of blood samples.
Body weight and weight changes:
effects observed, non-treatment-related
Description (incidence and severity):
The weight development of all groups took a normal course throughout the study with the exception of the male group treated with 450 mg/kg/day. In this group, 4 rats did not receive their diet as a result of a blockage of the feed containers for some days. In this study, there was no influence of the test article butyl methoxydibenzoylmethane (BMDBM) on the body weight development.
Food consumption and compound intake (if feeding study):
effects observed, non-treatment-related
Description (incidence and severity):
The feed consumption of males and females treated with 200 mg/kg bw/day was slightly higher than that of the control animals whereas males and females treated with 450 and 1000 mg/kg bw/day consumed less feed than control animals. These observations can be correlated with the body weight development.
The compound intakes are listed in table 4 and were all slightly higher than the intended dose.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Description (incidence and severity):
No findings were observed in eyes of control rats and rats treated with 1000 mg/kg bw/day.
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
All mean values of haematologic parameters were within the normal limits for rats in this laboratory at weeks 2 and 6, but at week 14, the mean RBC and Hb values of females treated with 1000 mg/kg bw/day nearly lay at the lower limit and were clearly lower than the mean RBC and Hb values of the female control group. The trend referring to the RBC decrease in the female group treated with 1000 mg/kg bw/day already occurred at week 6.
The RBC decrease in females treated with 1000 mg/kg bw/day was considered to be related to treatment.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
The mean values of parameters of clinical chemistry listed in table 6 minimally laid outside of the physiological range for rats in this laboratory. These findings were considered to be treatment-related but not systematizable.
A few particular values clearly jutted out from the physiological range (AST in 1 animal of the control group, GLDH in 1 animal of the low-dose and in 2 animals of the high-dose group). These observations were not considered to be of toxicological importance.
Urinalysis findings:
no effects observed
Description (incidence and severity):
Urinalysis results were similar in treated and control groups.
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):
With the exception of liver weights, all organ weights laid within the physiological range for rats in this laboratory. Mean relative liver weights of male rats treated with 1000 mg/kg bw/day as well mean absolute and mean relative liver weights of female rats treated with 200 mg/kg bw/day approached the upper limit of normal (table 7). Mean absolute and mean relative liver weights of female rats treated with 450 and 1000 mg/kg bw/day laid above of the physiological range.
These observations can be correlated with the slight increase in size of hepatic parenchyma cells in female rats treated with 1000 mg/kg bw/day (the lower dose groups were not examined).
The described increase of liver weights were considered to be related to treatment.
After a treatment-free period of 4 weeks, liver weights of male and female rats formerly treated with 1000 mg/kg bw/day were comparable with liver weights of control rats.
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
Necropsy findings were sporadic and consisted of bladder concrement and renal and ovarian cysts.
These observations were accidental findings which were not considered to be related to treatment.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
The histopathological changes are summarized in table 8.
With the exception of the slight increase in size of hepatic parenchyma cells, all other changes were not considered to be of toxicological importance. The incidence, degree, and group distribution of these changes did not show any effect of the treatment with BMDBM on a cellular structure of the examined organs and tissues.

The oral administration of BMDBM when given for 13 weeks caused a slight reduction of red blood cells in female rats treated with 1000 mg/kg/day. The quantity of reticulocytes was normal and the bone marrow was unchanged. The reason for the erythrocytes reduction was not detected.
The absolute and relative liver weights were higher in male rats treated with 1000 mg/kg/day and in all female dose groups than those in the control groups. In addition, a hepatocellular hypertrophy appeared in female rats treated with 1000 mg/kg/day (the lower dose groups were not examined). These findings were signs of an intensification of hepatic function which was interpreted as a process of adaptation because the liver weights of high dosed males and females were normalized after a treatment-free period of 4 weeks.
In all probability, the petty shifts of concentration of plasma proteins have connection with the process of adaption.
Histopathological findings: neoplastic:
not examined
Key result
Dose descriptor:
NOAEL
Effect level:
450 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Remarks on result:
not determinable due to absence of adverse toxic effects
Key result
Dose descriptor:
LOAEL
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Significant incresed liver weights and reduced Hb and RBC in the females of the 1000 mg/kd bw/day dose group.
Key result
Critical effects observed:
not specified

Table 3: Clinical observations made during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to rats over 90 days.

Symptom

Control

BMDBM [mg/kg bw/day]

200

450

1000

Loss of hair

1F

2F

-

2F

Exitation

-

1F

2M

1M

Crusted eye

-

-

1F

1M

F: female, M. male

 

Table 4: Compound intake during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to rats over 90 days.

Intended dose
[mg/kg bw/day]

Mean compound intake [mg/kg bw/day]

Males

Females

0

0.00

0.00

200

204.27

202.64

450

459.34

247.73

1000

1019.32

1012.75

 

Table 5:Selected haematology findingsmade during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to female rats over 90 days.

 

Control

BMDBM [mg/kg bw/day]

200

450

1000

Red blood cell count (Mio./µL)

Week 2

7.55 ± 0.30

7.29 ± 0.28

7.38 ± 0.39

7.38 ± 0.34

Week 6

8.28 ± 0.16

8.03 ± 0.34

7.96 ± 0.32

7.88 ± 0.17

Week 14

8.38 ± 0.10

8.29 ± 0.29

8.15 ± 0.30

7.77 ± 0.20

Hemoglobin (g/dL)

Week 2

15.7 ± 0.6

15.1 ± 0.8

15.2 ± 0.9

15.0 ± 0.6

Week 6

16.5 ± 0.4

15.7 ± 0.5

15.7 ± 0.3

15.6 ± 0.5

Week 14

16.0 ± 0.2

15.5 ± 0.6

15.4 ± 0.7

14.3 ± 0.2

 

Table 6: Selected clinical chemistry findingsmade during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to rats over 90 days

Test group [mg/kg bw/day]

Sex

Parameter

Week

Change

1000

Males

Potassium

6

Increased

1000

Males

Albumin [%]

6

Increased

1000

Males

Albumin [g/L]

6

Increased

1000

Males

Albumin/globulin

6

Increased

1000

Females

Albumin [%]

6

Increased

450, 1000

Females

alpha-Globulin 3 [%]

6

Decreased

450, 1000

Females

alpha-Globulin 3 [g/L]

6

Decreased

1000

Females

Albumin/globulin

6

Increased

1000

Females

Albumin [%]

14

Increased

200, 450, 1000

Females

beta-Globulin 3 [%]

14

Decreased

200, 450, 1000

Females

beta-Globulin 3 [g/L]

14

Decreased

1000

Females

Albumin/globulin

14

Increased

 

Table 7: Absolute liver and liver-to-brain ratios of rats fed butyl methoxydibenzoylmethane (BMDBM) over 90 days

 

Control

BMDBM [mg/kg bw/day]

200

450

1000

Males

Absolute [g]

15.557 ± 2.153

16.198 ± 2.517

16.836 ± 1.820

17.263 ± 2.363

Relative [g/ 100g bw]

6.04 ± 0.73

6.40 ± 0.71

6.77 ± 0.50

7.46 ± 0.87 *

Males (4 weeks recovery)

Relative [g/ 100g bw]

6.17 ± 0.54

 

 

6.36 ± 0.43

Females

Absolute [g]

8.517 ± 0.847

10.312 ± 1.203

10.900 ± 0.723

11.101 ± 2.107

Relative [g/ 100g bw]

5.42 ± 0.45

6.60 ± 0.63##

7.26 ± 0.47 **

8.59 ± 0.74 **

Females (4 weeks recovery)

Relative [g/ 100g bw]

5.73 ± 0.34

 

 

6.25 ± 0.60

* P<0.05 (Jonckheere test)

** P<0.01 (Jonckheere test)

##P<0.01 (U-test)

 

Table 8: Number of animals with gross, non-neoplastic, or neoplastic lesions at end of dosing period.

SEX

males

females

DAILY DOSE
(mg/kg bw/day)

0

1000

0

1000

NUMBER OF ANIMALS EXAMINED

6

6

6

6

Heart

Non-neoplastic lesion:

 

 

 

 

Myocardial necrosis, slight

1

 

 

 

Multifocal lympho-histiocytic infiltration

of the interstice, minimal to slight

5

5

5

5

Small accumulation of inflammatory cells within of the ventricle, minimal

1

 

1

 

Small focus of cartilage, minimal

1

2

 

 

Neoplastic lesion:

 

 

 

 

Lung

Non-neoplastic lesion:

 

 

 

 

Small atelectatic region, minimal

1

 

 

1

Small focus of inflammatory cells in the interstice, minimal

 

 

1

1

Diffuse infiltration of inflammatory cells in the connective tissue, minimal

 

 

 

1

Trachea

Non-neoplastic lesion:

 

 

 

 

Desquamation of epithelial cells, minimal

1

 

 

 

Liver

Non-neoplastic lesion:

 

 

 

 

Lympho-histiocytic infiltration of portal tracts with altered bile ducts, minimal to moderate

3

6

6

6

Multifocal infiltration of the parenchyma by mainly lymphocytes and histiocytes, minimal to moderate

6

6

4

6

Focal necroses in the parenchyma, minimal to moderate

1

3

1

2

Increased fat content, minimal to slight

2

 

 

 

Slight increase in size of hepatic parenchyma cells

 

 

 

6

Pancreas

Non-neoplastic lesion:

 

 

 

 

Area with increase of connective tissue and loose infiltration by inflammatory cells and destruction

of the exocrine parenchyma, minimal to moderate

1

2

 

1

Perivascular accumulation of lymphocytes, minimal

 

 

3

 

Kidney

Non-neoplastic lesion:

 

 

 

 

Subcapsular lympho-histiocytic infiltration, minimal

 

1

 

 

Perivascular lympho-histiocytic infiltration, minimal

1

1

 

3

Lympho-histiocytic infiltration with necrosis of epithelium of renal tubules, minimal

1

2

1

 

Nephrocalcinosis, minimal

 

 

3

3

Thyroid

Non-neoplastic lesion:

 

 

 

 

Desquamation of epithelial cells, minimal to moderate

6

4

4

4

Thyroid of recovery animals

Non-neoplastic lesion:

 

 

 

 

Desquamation of epithelial cells, minimal to slight

2

5

5

3

Adrenal gland

Non-neoplastic lesion:

 

 

 

 

Focal infiltration by mainly lymphocytes, minimal

1

2

1

3

Testis

Non-neoplastic lesion:

 

 

 

 

Damage of the germinal epithelium, moderate to severe

 

1

 

 

Bone

Non-neoplastic lesion:

 

 

 

 

Epiphyseal plate with an irregula region, minimal

 

 

1

1

 

Conclusions:
Under the conditions of this study, the NOAEL was considered to be 450 mg/kg bw/day. A significant increase in absolute and relative liver weight was observed in female rats at 450 and 1000 mg/kg bw/day and in male rats at 1000 mg/kg bw/day. Furthermore, a decrease in RBC and Hb was observed in female animals at 1000 mg/kg bw/day.
Executive summary:

The UV-A filter butyl methoxydibenzoylmethane (BMDBM) was administered as feed admix during 13 weeks. Four test groups each consisting of 12 rats per sex were formed. The animals received 0, 200, 450, and 1000 mg active ingredient per kg body weight per day. Mortality, general symptoms, and body weights were recorded. Haematology and clinical chemistry determinations were performed. All rats were autopsied. Organs and tissues of the control rats and rats treated with 1000 mg/kg bw/day were microscopically examined.

Deaths related to treatment did not occur throughout the test period. Two female rats died as a result of anaesthesia. Treatment-related clinical symptoms were not observed. The treatment with BMDBM did not have an effect on the weight development and feed consumption. The number of red blood cells was decreased in female rats treated with 1000 mg/kg bw/day. The results of the urinalysis were normal. No findings were observed in eyes of control rats and rats treated with 1000 mg/kg bw/day. No treatment-related necropsy findings were seen. The liver weights of male rats treated with 1000 mg/kg bw/day and of females treated with 200, 450, and 1000 mg/kg bw/day were higher than those of the control groups. The liver weight increase in the animals treated with 200 mg/kg bw/day could be attributed to their higher body weight compared to the control animals, but the effect in the higher dose groups must be considered as related to treatment. After a treatment-free period of 4 weeks, the high dosed male and female rats had a normal liver weight. With the exception of hepatic parenchyma cells which became hypertrophic in females treated with 1000 mg/kg bw/day, no histopathological changes were considered to be related to treatment.

Under the conditions of this study, the maximum oral dose level producing no toxic effect (NOAEL) was considered to be 450 mg/kg bw/day. The increase of liver weights as well the increase of hepatic parenchyma cells were interpreted as a process of liver adaption to treatment.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
450 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
similar to OECD TG 408

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records
Reference
Endpoint:
sub-chronic toxicity: inhalation
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Link to relevant study records
Reference
Endpoint:
sub-chronic toxicity: inhalation
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1979-11-08 - 1980-06-27
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)
Deviations:
yes
Remarks:
: use of intact as well as abraded skin
GLP compliance:
no
Limit test:
no
Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hacking & Churchill Ltd. Wyton, Huntingdon, Cambs., England
- Age at study initiation: 11 -14 weeks
- Weight at study initiation: 2.0 - 2.8 kg
- Housing: individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 20 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 °C
- Humidity (%): 45 ± 10 %
- Air changes (per hr): 19

IN-LIFE DATES: From: 1979-11-08 To:1979-11-30
Type of coverage:
occlusive
Vehicle:
other: Carbitol (diethylene glycol monoethyl ether)
Details on exposure:
TEST SITE
- Area of exposure: mid dorsal
- % coverage: approx. 10 % of body surface
- Type of wrap if used: occlusive bandage consisting of a gauze covered with Elastoplast elastic adhesive dressing backed with impervious Sleek plaster.
- Time intervals for shavings or clippings: Abrasion was carried out weekly and hair clipping was repeated daily.

REMOVAL OF TEST SUBSTANCE
- Washing: with warm tap water
- Time after start of exposure: 6 h

TEST MATERIAL
- Concentration: 30, 100, and 360 mg/kg bw/day
- Constant volume used: yes
- For solids, paste formed: yes

VEHICLE
- Justification for use and choice of vehicle (if other than water): Carbinol, due to the good solubility of the test item
- Amount(s) applied: 2 mL/kg bw/day
- Lot/batch no.: 19431787 and B711019

USE OF RESTRAINERS FOR PREVENTING INGESTION: yes
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
6 h per day
Frequency of treatment:
21 days
Dose / conc.:
0 mg/kg bw/day (nominal)
Dose / conc.:
30 mg/kg bw/day (nominal)
Dose / conc.:
100 mg/kg bw/day (nominal)
Dose / conc.:
360 mg/kg bw/day (nominal)
No. of animals per sex per dose:
10 males and 10 females per dose group. Half of the animals were tested with intact the other half was tested with abraded skin.
Control animals:
yes, concurrent no treatment
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: tested up to the highest soluble concentration
Positive control:
No positive control used.
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: daily, prior to application

BODY WEIGHT: Yes
- Time schedule for examinations: at the start of dosing and then twice weekly (days 1, 5, 8, 12, 15, 19, and 22)

FOOD CONSUMPTION:
- Food consumption for each animal determined: Yes

WATER CONSUMPTION: Yes
- Time schedule for examinations: only during week 3

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to treatment and then during the 3rd week of treatment
- Anaesthetic used for blood collection: No
- Animals fasted: Yes
- How many animals: prior to treatment: all animals; during the 3rd week of treatment: 5 male and 5 female rabbits with abraded skin from each group
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to treatment and then during the 3rd week of treatment
- Animals fasted: Yes
- How many animals: prior to treatment: all animals; during the 3rd week of treatment: 5 male and 5 female rabbits with abraded skin from each group
- Parameters checked in table 1 were examined.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table)
HISTOPATHOLOGY: Yes (see table) / No / No data
Statistics:
Analysis of variance followed by Student's t-test was used to assess the significance of intergroup differences in clinical laboratory data.
Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
No behavioural changes or signs of toxicosis were observed amongst surviving rabbits during the study period. Soft faeces and/or diarrhoea of a sporadic nature were observed in surviving rabbits from all groups, including the controls. This finding was considered to be incidental and not related to treatment with butyl methoxydibenzoylmethane (BMDBM).
Dermal irritation:
effects observed, treatment-related
Description (incidence and severity):
(Tables 5a and b)
Sporadic slight erythema was observed in three negative control rabbits during week 3 of the study.
Slight dermal reactions were generally seen in all rabbits treated with Carbitol (vehicle control) during weeks 2 and 3 of the study and well-defined erythema was recorded in five rabbits of this group during week 3.
The severity of dermal reactions of rabbits receiving BMDBM was generally greater than the controls and increased in a dosage-related manner. Slight to well-defined dermal reactions were observed from Day 6 to the end of the treatment period in all rabbits treated with BMDBM 30 or 100 mg/kg/day, although well-defined reactions were more persistent in rabbits of Group 4 (BMDBM, 100 mg/kg/day). Well-defined to moderate dermal reactions were generally seen in all rabbits treated with BMDBM, 360 mg/kg/day during this period.
Dryness and sloughing of the epidermis was observed in the majority of rabbits treated with BMDBM and the incidence was seen to increase with dosage. This finding was also observed in only 3 rabbits treated with Carbitol (vehicle control) but was not observed in procedural control rabbits.
There were no apparent differences in the dermal reactions of rabbits with intact or abraded skin condition within each group.
Mortality:
mortality observed, non-treatment-related
Description (incidence):
Five rabbits died during the study period and one rabbit was sacrificed in extremis. The distribution of the animal mortality was not dependent on test item treatment and is tabulated in table 3.
Body weight and weight changes:
effects observed, non-treatment-related
Description (incidence and severity):
No treatment-related trends were apparent (Table 4). Bodyweight losses on day 19 in the majority of the control and treated rabbits with abraded skin were considered to be a result of overnight food deprivation prior to removal of blood samples on day 19.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No treatment-related trends were apparent.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
no effects observed
Description (incidence and severity):
No treatment-related trends were apparent.
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Description (incidence and severity):
There were no changes that were considered to be related to treatment with BMDBM.
Statistical analysis of values from the week 3 investigations revealed statistical significances in comparison to the controls. These differences were not considered to be of toxicological importance and variations in values for individual rabbits were considered to bias statistical analysis in these instances.
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
There were no apparent changes that were considered to be directly related to treatment with BMDBM.
Statistical analysis of values from the week 3 investigations revealed statistical significances in comparison to the controls. These differences were not considered to be of toxicological importance and variations in values for individual rabbits were considered to bias statistical analysis in these instances.
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
No changes were seen that were considered to be related to treatment with BMDBM.
Group mean organ weights for some groups attained statistical significance in comparison with control values. These findings were not considered to be of toxicological importance and variations in values for individual rabbits were considered to bias statistical analysis in these instances.
Gross pathological findings:
no effects observed
Description (incidence and severity):
No changes were seen that were considered to be indicative of a treatment-related effect.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
Skin: No abnormalities were seen in skin taken from procedural control group rabbits or from the untreated control sites on the animals in the treated groups. In treated skin samples from the vehicle control group and the treatment groups a minimal focal to moderate generalised increase in epidermal thickness was recorded. This was occasionally but in frequently associated with a minimal cutaneous inflammatory infiltration. No quantitative differences could be determined between animals with intact or abraded skin.
The severity of the epidermal change showed no dose-relationship in treated groups and this was considered to be similar to the severity if this change observed in the vehicle control group.
Liver: Pericholangitis characterised by occasional parenchymal or portal foci if mononuclear cell infiltration in a proportion of animals from each group. Hepatocyte necrosis in occasional rabbits.
Kidneys: Varying degrees of chronic interstitial nephritis and fibrosis in a large proportion of rabbits from both control and treatment groups. No significant differences in terms of severity are distinguishable that might be ascribed to the vehicle or the test compound.
Gastro-intestinal tract: Chronic inflammatory bowel lesions of the gastro-intestinal mucosa in a small number of rabbits at termination and in all decedents. These lesions were probably due to a localised infection and considered a contributing factor to death in the decedents in this study. This was considered to be unrelated to treatment.
Brain: Perivascular inflammatory cuffing and cerebral gliosis and granulomata in a proportion of rabbits from all groups. These lesions were probably indicative of an enzephalitozoon infestation.
Histopathological findings: neoplastic:
not examined
Key result
Dose descriptor:
NOAEL
Remarks:
systemic
Effect level:
360 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Remarks on result:
not determinable due to absence of adverse toxic effects
Key result
Dose descriptor:
LOAEL
Remarks:
systemic
Effect level:
> 360 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: As the animals showed no systemic signs of toxicity with the highest concentration used, no LOAEL for systemic toxicity could be identified.
Remarks on result:
not determinable due to absence of adverse toxic effects
Dose descriptor:
LOAEL
Remarks:
local
Effect level:
100 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: In this concentration, distinct local effects (formation of erythema / edema) were visible after treatment.
Key result
Critical effects observed:
not specified

Table 3: Summarized mortalities after repeated dermal application of butyl methoxydibenzoylmethane (BMDBM) to rabbits.

Group

Mortalities

Total per group

Mortality

Males

Females

1

Negative control

0

2

2/20

10 %

2

Vehicle control

2

0

2/20

10 %

3

BMDBM 30 mg/kg bw/day

0

1

1/20

5 %

4

BMDBM 100 mg/kg bw/day

0

0

0/20

0 %

5

BMDBM 360 mg/kg bw/day

1

0

1/20

5 %

 

Table 4: Group mean bodyweights (g) of rabbits after repeated dermal application of BMDBM.

Group

Skin

Bodyweight [g] on day

Bodyweight change days 1 - 22

as % of controls

0

5

8

12

15

19

22

Male

1

Negative control

Intact

Abraded

2927

2968

2895

3026

2939

3068

3037

3177

3088

3262

3063

3171

3106

3270

179

302

-

-

2

Vehicle control

Intact

Abraded

2928

2962

2936

2980

2931

3023

2990

3162

3086

3203

2994

3134

3360

3286

432

324

241

107

3

BMDBM 30 mg/kg bw/day

Intact

Abraded

2962

2947

2976

2992

3013

3046

3082

3127

3156

3201

3194

3056

3212

3216

250

269

140

89

4

BMDBM 100 mg/kg bw/day

Intact

Abraded

2943

2938

2981

2935

3010

3012

3093

3100

3195

3171

3237

3130

3263

3213

320

275

179

91

5

BMDBM 360 mg/kg bw/day

Intact

Abraded

2934

2942

2950

2926

2934

2981

3047

3077

3056

3157

3114

3109

3151

3252

217

310

121

103

Female

1

Negative control

Intact

Abraded

2873

2854

2907

2781

2912

2910

2923

2984

2961

3085

3022

3030

3002

3080

129

226

-

-

 

2

Vehicle control

Intact

Abraded

2871

2871

2928

2910

3047

2903

3145

3028

3224

3093

3296

3105

3329

3184

458

 

313

355

138

3

BMDBM 30 mg/kg bw/day

Intact

Abraded

2888

2866

2875

2860

2910

2897

2949

3004

3008

3120

3116

3049

3131

3189

243

323

188

143

4

BMDBM 100 mg/kg bw/day

Intact

Abraded

2861

2861

2934

2917

2980

2948

3072

3007

3122

3082

3240

3114

3255

3114

394

253

305

112

5

BMDBM 360 mg/kg bw/day

Intact

Abraded

2856

2785

2927

2858

2961

2908

3063

2988

3165

3084

3213

2971

3280

3128

424

343

329

152

 

Table 5a: Mean erythema (E) and oedema (O) scores after repeated dermal application of butyl methoxydibenzoylmethane (BMDBM) to 5 male rabbits (intact skin).

Day

Negative control

Vehicle control

BMDBM [mg/kg bw/day]

30

100

360

Erythema/Oedema:

E

O

E

O

E

O

E

O

E

O

1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

2

0.0

0.0

0.0

0.0

0.0

0.0

0.2

0.0

0.0

0.0

3

0.0

0.0

0.0

0.0

0.4

0.0

0.6

0.2

0.6

0.8

4

0.0

0.0

0.2

0.0

1.0

0.0

1.2

0.8

1.0

1.2

5

0.0

0.0

0.4

0.2

1.0

0.8

1.6

1.0

1.2

1.8

6

0.0

0.0

0.0

0.0

0.8

0.8

1.8

1.8

2.0

2.0

7

0.0

0.0

0.4

0.0

1.2

0.8

1.6

2.0

2.0

2.0

8

0.0

0.0

0.6

0.2

1.0

1.0

1.6

2.0

2.0

2.0

9

0.0

0.0

0.2

0.0

1.0

0.6

1.6

1.2

2.0

1.8

101

0.0

0.0

0.8

0.0

1.0

0.8

1.8

1.4

2.0

2.0

11

0.0

0.0

0.5

0.0

0.8

0.6

1.6

1.4

2.0

2.0

12

0.0

0.0

1.0

0.0

1.0

0.6

1.6

1.6

2.0

2.0

13

0.0

0.0

0.8

0.0

1.0

0.6

1.6

1.2

2.0

2.2

14

0.0

0.0

0.8

1.0

1.0

0.8

1.8

1.2

2.0

2.4

15

0.0

0.0

0.8

0.3

1.2

0.8

2.0

1.6

2.0

2.0

16

0.0

0.0

0.8

0.3

1.2

0.6

2.0

1.6

2.0

1.6

17

0.0

0.0

0.8

0.3

1.2

0.8

2.0

1.6

2.0

1.8

18

0.0

0.0

0.8

0.3

1.2

0.8

2.0

1.8

2.0

1.8

19

0.4

0.4

1.3

0.5

1.2

1.0

1.6

1.8

2.0

2.2

20

0.0

0.0

1.0

0.5

1.2

1.0

1.8

1.8

2.0

2.0

21

0.0

0.0

1.3

0.5

1.2

1.0

2.0

1.8

2.0

2.0

222

0.0

0.0

1.3

0.3

1.2

1.0

2.0

1.8

2.0

2.2

23

0.0

0.0

1.3

1.0

1.0

1.0

2.0

2.0

2.0

2.0

1 1 out of 5 animals was found dead in the negative control group

2 1 out of 5 animals was found dead in the negative control group

 

Table 5b: Mean erythema (E) and oedema (O) scores after repeated dermal application of butyl methoxydibenzoylmethane (BMDBM) to 5 female rabbits (intact skin).

 

Negative control

Vehicle control

BMDBM [mg/kg bw/day]

30

100

360

Erythema/Oedema:

E

O

E

O

E

O

E

O

E

O

1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

2

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

3

0.0

0.0

0.2

0.0

0.6

0.0

0.6

0.2

0.4

0.0

4

0.0

0.0

0.4

0.0

0.6

0.0

0.8

0.4

1.4

0.8

5

0.0

0.0

0.8

0.4

1.4

1.4

1.2

1.4

2.0

1.8

6

0.0

0.0

0.4

0.0

1.2

1.0

1.8

1.6

2.2

2.0

7

0.0

0.0

0.4

0.2

1.0

1.2

1.6

1.8

2.2

2.0

81

0.0

0.0

0.2

0.0

1.0

1.3

1.4

1.8

2.0

2.0

9

0.0

0.0

0.0

0.0

1.0

0.3

1.6

1.2

2.0

1.8

10

0.0

0.0

0.0

0.0

1.0

0.8

1.6

1.4

2.0

2.0

11

0.0

0.0

0.8

0.4

1.0

0.5

1.8

1.4

2.0

2.0

122

0.0

0.0

0.8

0.4

1.0

1.0

2.0

1.6

2.0

2.0

13

0.0

0.0

0.8

0.2

1.0

0.8

2.0

1.4

2.0

2.2

14

0.0

0.0

0.8

0.2

1.0

1.0

2.0

1.8

2.0

2.4

15

0.0

0.0

0.8

0.2

1.5

1.0

2.0

1.6

2.2

2.2

163

0.0

0.0

0.8

0.4

1.3

0.3

2.0

1.0

1.8

2.0

17

0.0

0.0

0.8

0.6

1.3

0.5

2.0

1.0

2.0

2.0

18

0.0

0.0

0.8

0.6

1.5

0.8

2.0

1.2

2.0

2.0

19

0.0

0.0

1.0

0.8

1.0

1.0

1.6

1.2

2.0

2.0

20

0.0

0.0

1.0

1.0

1.0

1.0

1.8

1.4

2.0

2.2

21

0.0

0.0

1.2

0.8

1.0

1.0

2.0

1.6

2.0

2.6

22

0.0

0.0

1.0

0.8

1.0

1.0

1.8

1.8

2.0

2.2

23

0.0

0.0

1.0

0.0

1.0

1.0

2.0

2.0

2.0

2.3

1 1 out of 5 animals was found dead in the 30 mg/kg bw group

2 1 out of 5 animals was found dead in the negative control group

3 1 out of 5 animals was found dead in the negative control group

Conclusions:
Repeated (21 days) dermal application of BMDBM (30, 100, and 360 mg/kg bw/day) to the intact or abraded skin of rabbits caused no deaths. Therefore, the NOAEL for systemic toxicity was set to the highest applied dose of 360 mg/kg bw/day. There was a dosage-related increase in the severity of dermal reactions of rabbits treated with BMDBM, including slight to moderate erythema and edema. The respective vehicle control exhibited only slight dermal reactions.
Executive summary:

BMDBM, a crystalline sun protection substance, was prepared freshly each day as 1.5, 5 and 18 % w/v solutions in Carbitol and applied to the skin of rabbits once daily at dosage levels of 30, 100 and 360 mg/kg bw/day, for an exposure period of six hours each day, for twenty-one consecutive days.

There was a dosage-related increase in the severity of dermal reactions of rabbits treated with BMDBM. Slight to well-defined dermal reactions were generally observed in rabbits treated with BMDBM 30 or 100 mg/kg bw/day, although well-defined reactions were more persistent in rabbits treated with BMDBM, 100 mg/kg bw/day. Well-defined to moderate dermal reactions were generally seen in rabbits treated with BMDBM, 360 mg/kg/day. Slight dermal reactions occurred in the vehicle control animals (Carbitol). Microscopic examination of the treated skin sites revealed an increased incidence of epidermal thickening in rabbits from the vehicle control and treatment groups when compared to the untreated control group. Five rabbits were found dead during the study and one rabbit was sacrificed. The death of these animals was not considered to be directly related to treatment. Histopathological examination revealed gastrointestinal infection to be a factor contributory to the death of each animal.

In all other aspects including general health, bodyweights, food consumption, water consumption, haematology, blood chemistry, organ weights macroscopic pathology, and microscopic pathology of tissues excluding skin, rabbits treated with BMDBM were similar to the procedural and vehicle controls. Therefore, the NOAEL, based on systemic effects, can be considered to be 360 mg/kg bw/day.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
360 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
similar to OECD TG 410

Repeated dose toxicity: dermal - local effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1979-11-08 - 1980-06-27
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)
Deviations:
yes
Remarks:
: use of intact as well as abraded skin
GLP compliance:
no
Limit test:
no
Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hacking & Churchill Ltd. Wyton, Huntingdon, Cambs., England
- Age at study initiation: 11 -14 weeks
- Weight at study initiation: 2.0 - 2.8 kg
- Housing: individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 20 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 °C
- Humidity (%): 45 ± 10 %
- Air changes (per hr): 19

IN-LIFE DATES: From: 1979-11-08 To:1979-11-30
Type of coverage:
occlusive
Vehicle:
other: Carbitol (diethylene glycol monoethyl ether)
Details on exposure:
TEST SITE
- Area of exposure: mid dorsal
- % coverage: approx. 10 % of body surface
- Type of wrap if used: occlusive bandage consisting of a gauze covered with Elastoplast elastic adhesive dressing backed with impervious Sleek plaster.
- Time intervals for shavings or clippings: Abrasion was carried out weekly and hair clipping was repeated daily.

REMOVAL OF TEST SUBSTANCE
- Washing: with warm tap water
- Time after start of exposure: 6 h

TEST MATERIAL
- Concentration: 30, 100, and 360 mg/kg bw/day
- Constant volume used: yes
- For solids, paste formed: yes

VEHICLE
- Justification for use and choice of vehicle (if other than water): Carbinol, due to the good solubility of the test item
- Amount(s) applied: 2 mL/kg bw/day
- Lot/batch no.: 19431787 and B711019

USE OF RESTRAINERS FOR PREVENTING INGESTION: yes
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
6 h per day
Frequency of treatment:
21 days
Dose / conc.:
0 mg/kg bw/day (nominal)
Dose / conc.:
30 mg/kg bw/day (nominal)
Dose / conc.:
100 mg/kg bw/day (nominal)
Dose / conc.:
360 mg/kg bw/day (nominal)
No. of animals per sex per dose:
10 males and 10 females per dose group. Half of the animals were tested with intact the other half was tested with abraded skin.
Control animals:
yes, concurrent no treatment
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: tested up to the highest soluble concentration
Positive control:
No positive control used.
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: daily, prior to application

BODY WEIGHT: Yes
- Time schedule for examinations: at the start of dosing and then twice weekly (days 1, 5, 8, 12, 15, 19, and 22)

FOOD CONSUMPTION:
- Food consumption for each animal determined: Yes

WATER CONSUMPTION: Yes
- Time schedule for examinations: only during week 3

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to treatment and then during the 3rd week of treatment
- Anaesthetic used for blood collection: No
- Animals fasted: Yes
- How many animals: prior to treatment: all animals; during the 3rd week of treatment: 5 male and 5 female rabbits with abraded skin from each group
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to treatment and then during the 3rd week of treatment
- Animals fasted: Yes
- How many animals: prior to treatment: all animals; during the 3rd week of treatment: 5 male and 5 female rabbits with abraded skin from each group
- Parameters checked in table 1 were examined.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table)
HISTOPATHOLOGY: Yes (see table) / No / No data
Statistics:
Analysis of variance followed by Student's t-test was used to assess the significance of intergroup differences in clinical laboratory data.
Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
No behavioural changes or signs of toxicosis were observed amongst surviving rabbits during the study period. Soft faeces and/or diarrhoea of a sporadic nature were observed in surviving rabbits from all groups, including the controls. This finding was considered to be incidental and not related to treatment with butyl methoxydibenzoylmethane (BMDBM).
Dermal irritation:
effects observed, treatment-related
Description (incidence and severity):
(Tables 5a and b)
Sporadic slight erythema was observed in three negative control rabbits during week 3 of the study.
Slight dermal reactions were generally seen in all rabbits treated with Carbitol (vehicle control) during weeks 2 and 3 of the study and well-defined erythema was recorded in five rabbits of this group during week 3.
The severity of dermal reactions of rabbits receiving BMDBM was generally greater than the controls and increased in a dosage-related manner. Slight to well-defined dermal reactions were observed from Day 6 to the end of the treatment period in all rabbits treated with BMDBM 30 or 100 mg/kg/day, although well-defined reactions were more persistent in rabbits of Group 4 (BMDBM, 100 mg/kg/day). Well-defined to moderate dermal reactions were generally seen in all rabbits treated with BMDBM, 360 mg/kg/day during this period.
Dryness and sloughing of the epidermis was observed in the majority of rabbits treated with BMDBM and the incidence was seen to increase with dosage. This finding was also observed in only 3 rabbits treated with Carbitol (vehicle control) but was not observed in procedural control rabbits.
There were no apparent differences in the dermal reactions of rabbits with intact or abraded skin condition within each group.
Mortality:
mortality observed, non-treatment-related
Description (incidence):
Five rabbits died during the study period and one rabbit was sacrificed in extremis. The distribution of the animal mortality was not dependent on test item treatment and is tabulated in table 3.
Body weight and weight changes:
effects observed, non-treatment-related
Description (incidence and severity):
No treatment-related trends were apparent (Table 4). Bodyweight losses on day 19 in the majority of the control and treated rabbits with abraded skin were considered to be a result of overnight food deprivation prior to removal of blood samples on day 19.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No treatment-related trends were apparent.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
no effects observed
Description (incidence and severity):
No treatment-related trends were apparent.
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Description (incidence and severity):
There were no changes that were considered to be related to treatment with BMDBM.
Statistical analysis of values from the week 3 investigations revealed statistical significances in comparison to the controls. These differences were not considered to be of toxicological importance and variations in values for individual rabbits were considered to bias statistical analysis in these instances.
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
There were no apparent changes that were considered to be directly related to treatment with BMDBM.
Statistical analysis of values from the week 3 investigations revealed statistical significances in comparison to the controls. These differences were not considered to be of toxicological importance and variations in values for individual rabbits were considered to bias statistical analysis in these instances.
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
No changes were seen that were considered to be related to treatment with BMDBM.
Group mean organ weights for some groups attained statistical significance in comparison with control values. These findings were not considered to be of toxicological importance and variations in values for individual rabbits were considered to bias statistical analysis in these instances.
Gross pathological findings:
no effects observed
Description (incidence and severity):
No changes were seen that were considered to be indicative of a treatment-related effect.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
Skin: No abnormalities were seen in skin taken from procedural control group rabbits or from the untreated control sites on the animals in the treated groups. In treated skin samples from the vehicle control group and the treatment groups a minimal focal to moderate generalised increase in epidermal thickness was recorded. This was occasionally but in frequently associated with a minimal cutaneous inflammatory infiltration. No quantitative differences could be determined between animals with intact or abraded skin.
The severity of the epidermal change showed no dose-relationship in treated groups and this was considered to be similar to the severity if this change observed in the vehicle control group.
Liver: Pericholangitis characterised by occasional parenchymal or portal foci if mononuclear cell infiltration in a proportion of animals from each group. Hepatocyte necrosis in occasional rabbits.
Kidneys: Varying degrees of chronic interstitial nephritis and fibrosis in a large proportion of rabbits from both control and treatment groups. No significant differences in terms of severity are distinguishable that might be ascribed to the vehicle or the test compound.
Gastro-intestinal tract: Chronic inflammatory bowel lesions of the gastro-intestinal mucosa in a small number of rabbits at termination and in all decedents. These lesions were probably due to a localised infection and considered a contributing factor to death in the decedents in this study. This was considered to be unrelated to treatment.
Brain: Perivascular inflammatory cuffing and cerebral gliosis and granulomata in a proportion of rabbits from all groups. These lesions were probably indicative of an enzephalitozoon infestation.
Histopathological findings: neoplastic:
not examined
Key result
Dose descriptor:
NOAEL
Remarks:
systemic
Effect level:
360 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Remarks on result:
not determinable due to absence of adverse toxic effects
Key result
Dose descriptor:
LOAEL
Remarks:
systemic
Effect level:
> 360 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: As the animals showed no systemic signs of toxicity with the highest concentration used, no LOAEL for systemic toxicity could be identified.
Remarks on result:
not determinable due to absence of adverse toxic effects
Dose descriptor:
LOAEL
Remarks:
local
Effect level:
100 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: In this concentration, distinct local effects (formation of erythema / edema) were visible after treatment.
Key result
Critical effects observed:
not specified

Table 3: Summarized mortalities after repeated dermal application of butyl methoxydibenzoylmethane (BMDBM) to rabbits.

Group

Mortalities

Total per group

Mortality

Males

Females

1

Negative control

0

2

2/20

10 %

2

Vehicle control

2

0

2/20

10 %

3

BMDBM 30 mg/kg bw/day

0

1

1/20

5 %

4

BMDBM 100 mg/kg bw/day

0

0

0/20

0 %

5

BMDBM 360 mg/kg bw/day

1

0

1/20

5 %

 

Table 4: Group mean bodyweights (g) of rabbits after repeated dermal application of BMDBM.

Group

Skin

Bodyweight [g] on day

Bodyweight change days 1 - 22

as % of controls

0

5

8

12

15

19

22

Male

1

Negative control

Intact

Abraded

2927

2968

2895

3026

2939

3068

3037

3177

3088

3262

3063

3171

3106

3270

179

302

-

-

2

Vehicle control

Intact

Abraded

2928

2962

2936

2980

2931

3023

2990

3162

3086

3203

2994

3134

3360

3286

432

324

241

107

3

BMDBM 30 mg/kg bw/day

Intact

Abraded

2962

2947

2976

2992

3013

3046

3082

3127

3156

3201

3194

3056

3212

3216

250

269

140

89

4

BMDBM 100 mg/kg bw/day

Intact

Abraded

2943

2938

2981

2935

3010

3012

3093

3100

3195

3171

3237

3130

3263

3213

320

275

179

91

5

BMDBM 360 mg/kg bw/day

Intact

Abraded

2934

2942

2950

2926

2934

2981

3047

3077

3056

3157

3114

3109

3151

3252

217

310

121

103

Female

1

Negative control

Intact

Abraded

2873

2854

2907

2781

2912

2910

2923

2984

2961

3085

3022

3030

3002

3080

129

226

-

-

 

2

Vehicle control

Intact

Abraded

2871

2871

2928

2910

3047

2903

3145

3028

3224

3093

3296

3105

3329

3184

458

 

313

355

138

3

BMDBM 30 mg/kg bw/day

Intact

Abraded

2888

2866

2875

2860

2910

2897

2949

3004

3008

3120

3116

3049

3131

3189

243

323

188

143

4

BMDBM 100 mg/kg bw/day

Intact

Abraded

2861

2861

2934

2917

2980

2948

3072

3007

3122

3082

3240

3114

3255

3114

394

253

305

112

5

BMDBM 360 mg/kg bw/day

Intact

Abraded

2856

2785

2927

2858

2961

2908

3063

2988

3165

3084

3213

2971

3280

3128

424

343

329

152

 

Table 5a: Mean erythema (E) and oedema (O) scores after repeated dermal application of butyl methoxydibenzoylmethane (BMDBM) to 5 male rabbits (intact skin).

Day

Negative control

Vehicle control

BMDBM [mg/kg bw/day]

30

100

360

Erythema/Oedema:

E

O

E

O

E

O

E

O

E

O

1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

2

0.0

0.0

0.0

0.0

0.0

0.0

0.2

0.0

0.0

0.0

3

0.0

0.0

0.0

0.0

0.4

0.0

0.6

0.2

0.6

0.8

4

0.0

0.0

0.2

0.0

1.0

0.0

1.2

0.8

1.0

1.2

5

0.0

0.0

0.4

0.2

1.0

0.8

1.6

1.0

1.2

1.8

6

0.0

0.0

0.0

0.0

0.8

0.8

1.8

1.8

2.0

2.0

7

0.0

0.0

0.4

0.0

1.2

0.8

1.6

2.0

2.0

2.0

8

0.0

0.0

0.6

0.2

1.0

1.0

1.6

2.0

2.0

2.0

9

0.0

0.0

0.2

0.0

1.0

0.6

1.6

1.2

2.0

1.8

101

0.0

0.0

0.8

0.0

1.0

0.8

1.8

1.4

2.0

2.0

11

0.0

0.0

0.5

0.0

0.8

0.6

1.6

1.4

2.0

2.0

12

0.0

0.0

1.0

0.0

1.0

0.6

1.6

1.6

2.0

2.0

13

0.0

0.0

0.8

0.0

1.0

0.6

1.6

1.2

2.0

2.2

14

0.0

0.0

0.8

1.0

1.0

0.8

1.8

1.2

2.0

2.4

15

0.0

0.0

0.8

0.3

1.2

0.8

2.0

1.6

2.0

2.0

16

0.0

0.0

0.8

0.3

1.2

0.6

2.0

1.6

2.0

1.6

17

0.0

0.0

0.8

0.3

1.2

0.8

2.0

1.6

2.0

1.8

18

0.0

0.0

0.8

0.3

1.2

0.8

2.0

1.8

2.0

1.8

19

0.4

0.4

1.3

0.5

1.2

1.0

1.6

1.8

2.0

2.2

20

0.0

0.0

1.0

0.5

1.2

1.0

1.8

1.8

2.0

2.0

21

0.0

0.0

1.3

0.5

1.2

1.0

2.0

1.8

2.0

2.0

222

0.0

0.0

1.3

0.3

1.2

1.0

2.0

1.8

2.0

2.2

23

0.0

0.0

1.3

1.0

1.0

1.0

2.0

2.0

2.0

2.0

1 1 out of 5 animals was found dead in the negative control group

2 1 out of 5 animals was found dead in the negative control group

 

Table 5b: Mean erythema (E) and oedema (O) scores after repeated dermal application of butyl methoxydibenzoylmethane (BMDBM) to 5 female rabbits (intact skin).

 

Negative control

Vehicle control

BMDBM [mg/kg bw/day]

30

100

360

Erythema/Oedema:

E

O

E

O

E

O

E

O

E

O

1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

2

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

3

0.0

0.0

0.2

0.0

0.6

0.0

0.6

0.2

0.4

0.0

4

0.0

0.0

0.4

0.0

0.6

0.0

0.8

0.4

1.4

0.8

5

0.0

0.0

0.8

0.4

1.4

1.4

1.2

1.4

2.0

1.8

6

0.0

0.0

0.4

0.0

1.2

1.0

1.8

1.6

2.2

2.0

7

0.0

0.0

0.4

0.2

1.0

1.2

1.6

1.8

2.2

2.0

81

0.0

0.0

0.2

0.0

1.0

1.3

1.4

1.8

2.0

2.0

9

0.0

0.0

0.0

0.0

1.0

0.3

1.6

1.2

2.0

1.8

10

0.0

0.0

0.0

0.0

1.0

0.8

1.6

1.4

2.0

2.0

11

0.0

0.0

0.8

0.4

1.0

0.5

1.8

1.4

2.0

2.0

122

0.0

0.0

0.8

0.4

1.0

1.0

2.0

1.6

2.0

2.0

13

0.0

0.0

0.8

0.2

1.0

0.8

2.0

1.4

2.0

2.2

14

0.0

0.0

0.8

0.2

1.0

1.0

2.0

1.8

2.0

2.4

15

0.0

0.0

0.8

0.2

1.5

1.0

2.0

1.6

2.2

2.2

163

0.0

0.0

0.8

0.4

1.3

0.3

2.0

1.0

1.8

2.0

17

0.0

0.0

0.8

0.6

1.3

0.5

2.0

1.0

2.0

2.0

18

0.0

0.0

0.8

0.6

1.5

0.8

2.0

1.2

2.0

2.0

19

0.0

0.0

1.0

0.8

1.0

1.0

1.6

1.2

2.0

2.0

20

0.0

0.0

1.0

1.0

1.0

1.0

1.8

1.4

2.0

2.2

21

0.0

0.0

1.2

0.8

1.0

1.0

2.0

1.6

2.0

2.6

22

0.0

0.0

1.0

0.8

1.0

1.0

1.8

1.8

2.0

2.2

23

0.0

0.0

1.0

0.0

1.0

1.0

2.0

2.0

2.0

2.3

1 1 out of 5 animals was found dead in the 30 mg/kg bw group

2 1 out of 5 animals was found dead in the negative control group

3 1 out of 5 animals was found dead in the negative control group

Conclusions:
Repeated (21 days) dermal application of BMDBM (30, 100, and 360 mg/kg bw/day) to the intact or abraded skin of rabbits caused no deaths. Therefore, the NOAEL for systemic toxicity was set to the highest applied dose of 360 mg/kg bw/day. There was a dosage-related increase in the severity of dermal reactions of rabbits treated with BMDBM, including slight to moderate erythema and edema. The respective vehicle control exhibited only slight dermal reactions.
Executive summary:

BMDBM, a crystalline sun protection substance, was prepared freshly each day as 1.5, 5 and 18 % w/v solutions in Carbitol and applied to the skin of rabbits once daily at dosage levels of 30, 100 and 360 mg/kg bw/day, for an exposure period of six hours each day, for twenty-one consecutive days.

There was a dosage-related increase in the severity of dermal reactions of rabbits treated with BMDBM. Slight to well-defined dermal reactions were generally observed in rabbits treated with BMDBM 30 or 100 mg/kg bw/day, although well-defined reactions were more persistent in rabbits treated with BMDBM, 100 mg/kg bw/day. Well-defined to moderate dermal reactions were generally seen in rabbits treated with BMDBM, 360 mg/kg/day. Slight dermal reactions occurred in the vehicle control animals (Carbitol). Microscopic examination of the treated skin sites revealed an increased incidence of epidermal thickening in rabbits from the vehicle control and treatment groups when compared to the untreated control group. Five rabbits were found dead during the study and one rabbit was sacrificed. The death of these animals was not considered to be directly related to treatment. Histopathological examination revealed gastrointestinal infection to be a factor contributory to the death of each animal.

In all other aspects including general health, bodyweights, food consumption, water consumption, haematology, blood chemistry, organ weights macroscopic pathology, and microscopic pathology of tissues excluding skin, rabbits treated with BMDBM were similar to the procedural and vehicle controls. Therefore, the NOAEL, based on systemic effects, can be considered to be 360 mg/kg bw/day.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
6.6 mg/cm²
Study duration:
subacute
Species:
rabbit
Quality of whole database:
Spiers and Candas, J Appl Physiol. 1984 Jan;56(1):240-3: Skin surface area (Ab) of rat in relation to mass m is Ab = 6.88m^0.736. 300 g average weight for rats was assumed.

Additional information

Oral

The substance was administered as feed admix during 13 weeks. Four test groups each consisting of 12 rats per sex were formed. The animals received 0, 200, 450, and 1000 mg active ingredient per kg body weight per day. Mortality, general symptoms, and body weights were recorded. Haematology and clinical chemistry determinations were performed. All rats were autopsied. Organs and tissues of the control rats and rats treated with 1000 mg/kg bw/day were microscopically examined.

Deaths related to treatment did not occur throughout the test period. Two female rats died as a result of anaesthesia. Treatment-related clinical symptoms were not observed. The treatment with BMDBM did not have an effect on the weight development and feed consumption. The number of red blood cells was decreased in female rats treated with 1000 mg/kg bw/day. The results of the urinalysis were normal. No findings were observed in eyes of control rats and rats treated with 1000 mg/kg bw/day. No treatment-related necropsy findings were seen. The liver weights of male rats treated with 1000 mg/kg bw/day and of females treated with 200, 450, and 1000 mg/kg bw/day were higher than those of the control groups. The liver weight increase in the animals treated with 200 mg/kg bw/day could be attributed to their higher body weight compared to the control animals, but the effect in the higher dose groups must be considered as related to treatment. After a treatment-free period of 4 weeks, the high dosed male and female rats had a normal liver weight. With the exception of hepatic parenchyma cells which became hypertrophic in females treated with 1000 mg/kg bw/day, no histopathological changes were considered to be related to treatment.

Under the conditions of this study, the maximum oral dose level producing no toxic effect (NOAEL) was considered to be 450 mg/kg bw/day. The increase of liver weights as well the increase of hepatic parenchyma cells were interpreted as a process of liver adaption to treatment.

Dermal

The substance was prepared freshly each day as 1.5, 5 and 18 % w/v solutions in Carbitol and applied to the skin of rabbits once daily at dosage levels of 30, 100 and 360 mg/kg bw/day, for an exposure period of six hours each day, for twenty-one consecutive days. There was a dosage-related increase in the severity of dermal reactions of rabbits treated with BMDBM. Slight to well-defined dermal reactions were generally observed in rabbits treated with BMDBM 30 or 100 mg/kg bw/day, although well-defined reactions were more persistent in rabbits treated with BMDBM, 100 mg/kg bw/day. Well-defined to moderate dermal reactions were generally seen in rabbits treated with BMDBM, 360 mg/kg/day. Slight dermal reactions occurred in the vehicle control animals (Carbitol). Microscopic examination of the treated skin sites revealed an increased incidence of epidermal thickening in rabbits from the vehicle control and treatment groups when compared to the untreated control group. Five rabbits were found dead during the study and one rabbit was sacrificed. The death of these animals was not considered to be directly related to treatment. Histopathological examination revealed gastrointestinal infection to be a factor contributory to the death of each animal.

In all other aspects including general health, bodyweights, food consumption, water consumption, haematology, blood chemistry, organ weights macroscopic pathology, and microscopic pathology of tissues excluding skin, rabbits treated with BMDBM were similar to the procedural and vehicle controls. Therefore, the NOAEL, based on systemic effects, can be considered to be 360 mg/kg bw/day.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance is not considered to be classified for repeated dose toxicity under Regulation (EC) No 1272/2008, as amended for the twelfth time in Regulation (EU) 2019/521.