Fluometuron

Repeated dose toxicity: dermal

Administrative data

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 April to 16 May 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

No study guidelines are reported. The study has the following deficiencies when compared with the toxicity study in rats, oral route (method B.31 of Regulation (EC) No 440/2008): The study duration was 21 days compared to the required 28 days, the number of tissues taken for histopathology was less extensive than required, there is no reference to dose rate selection and the area treated is not recorded.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

no guideline followed

Guideline:

EU Method B.9 (Repeated Dose (28 Days) Toxicity (Dermal))

Deviations:

yes

Remarks:

The study duration was 21 days compared to the required 28 days, the number of tissues taken for histopathology was less extensive than required, there is no reference to dose rate selection and the area treated is not recorded

Principles of method if other than guideline:

The study duration was 21 days compared to the required 28 days, the number of tissues taken for histopathology was less extensive than required, there is no reference to dose rate selection and the area treated is not recorded

GLP compliance:

yes

Remarks:

self certification by laboratory

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Fluometuron

EC Number:

218-500-4

EC Name:

Fluometuron

Cas Number:

2164-17-2

Molecular formula:

C10H11F3N2O

IUPAC Name:

fluometuron

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material: fluometuron, 1,1-dimethyl-3-[3-(trifluoromethyl)phenyl]urea
- Physical state: white powder
- Analytical purity: not recorded
- Batch number: batch no. FL-851769
- Date of arrival: 21 February 1986

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

- group of five male and five female New Zealand white rabbits (SPF)
- Source: Hazleton Research Animals, Denver, P.A.
- weight: 2.42 - 3.38 kg
- age:twelve to sixteen weeks old
- free access to mains drinking water and food
- animal room temperature:67 +/- 5°F
- relative humidity: 30 - 70%

Administration / exposure

Type of coverage:

occlusive

Vehicle:

water

Details on exposure:

Groups of five female and five male New Zealand White albino rabbits received the test material as a 6-hour topical application to the clipped skin under occlusive bandages at doses of 0, 10, 100 or 1000 mg/kg for 21 days. The test material was applied as a paste in water.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

6-hour topical application/day for 21 days

Frequency of treatment:

procedures were completed daily from day 1 to the day prior sacrifice

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 10, 100, 1000 mg/kg
Basis:
nominal per unit body weight

No. of animals per sex per dose:

VEHICLE CONTROL: Dose level 0 mg/kg: 5 male and 5 female/dose
Treatment I: Dose level 10 mg/kg: 5 male and 5 female/dose
Treatment II: Dose level 100 mg/kg: 5 male and 5 female/dose
Treatment III: Dose level 1000 mg/kg: 5 male and 5 female/dose

Control animals:

yes, concurrent no treatment

Details on study design:

Groups of five female and five male New Zealand White albino rabbits received the test material as a 6-hour topical application to the clipped skin under occlusive bandages at doses of 0, 10, 100 or 1000 mg/kg for 21 days. The test material was applied as a paste in water:

Animals were randomly assigned to study groups prior to study initiation using a computer program employinq a method adapted from Carnaham, Luther, and Wilkes, Applied Numerical Methods, Wiley, 1969. Only animals considered to be in good health and with application sites free of abnormalities were included in the randomization procedure. Because of exclusion due to poor skin at the application site an an1mal with an eye abnormality was used on this study. To prevent confounding the results of the ophthalmology studies this animal was manually assigned to the vehicle control group.

Animal Preparation and Dosing Procedures
The back of each animal was clipped free of hair using electric clippers equipped with a number 40 (surgical) blade prior to initial applications of the test article paste. The application sites were reclipped twice each week during the study to ensure good material to skin contact.
As each test and vehicle control group animal was manually restrained, the pre-weighed test article and water paste was applied to the clipped application area and spread as evenly as possible over the test site using a wooden spatula. Any paste remaining in the individual test article container and on the wooden spatula was wiped off with a gauze pad. This gauze pad was then placed over the application site. The gauze pad and test article were held in place using a cellophane binder. This binder encircled the abdomen and was secured with several overlapping bands of masking tape at the anterior and posterior ends of the binder. Vehicle control animals were treated similarly except no test article paste was applied. Prior to applyinq binders to the vehicle control animals, the application site was moistened with the vehicle (distilled deionized water). After 6 hours of exposure, the adhesive tape, plastic binder, and gauze were removed and the application site was gently wiped with a gauze pad soaked in water to remove any remaining test article. These procedures were completed daily from day 1 to the day prior to sacrifice with the following exceptions:
- A low dose female was underdosed by approximately 13% for 5 consecutive days due to a calculation error.
- Wrapping materials were inadvertently not removed until the morning following application from 1 mid dose male on day 6.
Neither of the listed deviations from standard application procedure were considered to have an adverse impact on the outcome of the study.

Clinical Indices
All animals were observed for mortality and overt signs of toxicity twice daily during the study in the early morning and late afternoon. Any abnormalities observed during the twice daily checks or observed at any other time during the study were recorded. Prior to each day's treatment, the application site on each animal was evaluated for erythema and edema according to Draize. Any other dermal reactions were also recorded. Individual body weights were measured weekly. Animals found dead were weighed prior to necropsy. Terminal fasted body weights were recorded on the days of scheduled sacrifice.

Clinical pathology Studies
Blood samples (obtained via the orbital sinus) were collected from all animals prior to study initiation and prior to scheduled sacrifice. All animals were fasted for approximately 16 hours prior to blood collection.
Animals were randomly assigned to study groups prior to study initiation using a computer program employinq a method adapted from Carnaham, Luther, and Wilkes, Applied Numerical Methods, Wiley, 1969. Only animals considered to be in good health and with application sites free of abnormalities were included in the randomization procedure. Because of exclusion due to poor skin at the application site an an1mal with an eye abnormality was used on this study. To prevent confounding the results of the ophthalmology studies this animal was manually assigned to the vehicle control group.

Animal Preparation and Dosing Procedures
The back of each animal was clipped free of hair using electric clippers equipped with a number 40 (surgical) blade prior to initial applications of the test article paste. The application sites were reclipped twice each week during the study to ensure good material to skin contact.
As each test and vehicle control group animal was manually restrained, the pre-weighed test article and water paste was applied to the clipped application area and spread as evenly as possible over the test site using a wooden spatula. Any paste remaining in the individual test article container and on the wooden spatula was wiped off with a gauze pad. This gauze pad was then placed over the application site. The gauze pad and test article were held in place using a cellophane binder. This binder encircled the abdomen and was secured with several overlapping bands of masking tape at the anterior and posterior ends of the binder. Vehicle control animals were treated similarly except no test article paste was applied. Prior to applyinq binders to the vehicle control animals, the application site was moistened with the vehicle (distilled deionized water). After 6 hours of exposure, the adhesive tape, plastic binder, and gauze were removed and the application site was gently wiped with a gauze pad soaked in water to remove any remaining test article. These procedures were completed daily from day 1 to the day prior to sacrifice with the following exceptions:
- A low dose female was underdosed by approximately 13% for 5 consecutive days due to a calculation error.
- Wrapping materials were inadvertently not removed until the morning following application from 1 mid dose male on day 6.
Neither of the listed deviations from standard application procedure were considered to have an adverse impact on the outcome of the study.

Clinical Indices
All animals were observed for mortality and overt signs of toxicity twice daily during the study in the early morning and late afternoon. Any abnormalities observed during the twice daily checks or observed at any other time during the study were recorded. Prior to each day's treatment, the application site on each animal was evaluated for erythema and edema according to Draize. Any other dermal reactions were also recorded. Individual body weights were measured weekly. Animals found dead were weighed prior to necropsy. Terminal fasted body weights were recorded on the days of scheduled sacrifice.

Clinical pathology Studies
Blood samples (obtained via the orbital sinus) were collected from all animals prior to study initiation and prior to scheduled sacrifice.
All animals were fasted for approximately 16 hours prior to blood collection.

Examinations

Observations and examinations performed and frequency:

All animals were observed for mortality and overt signs of toxicity twice daily during the study in the early morning and late afternoon.
Blood samples (obtained via the orbital sinus) were collected from all animals prior to study initiation and prior to scheduled sacrifice.

Sacrifice and pathology:

ORGAN WEIGHTS
The following organs brain, adrenal, heart, kidney, liver, pituitary on both males and female animals were weighed at sacrifice and the organ weights, organ to body weight ratio, organ to brain weight ratio were calculated. Additional determinations were made on the testes with epididymides in males and ovaries in females. The fasted final body weight was also recorded. No statistically significant differences were detected
OPHTHLOMOLOGY
A small posterior capsular cataract was observed in a female dosed at 100 mg/kg. This was recorded as an incidental finding.
GROSS NECROPSY
There were no gross necropsy findings in the tissues of any group, which could be attributed to treatment with fluometuron technical. All findings were considered to be either spontaneous or consistent with a population of age matched experimental rabbits.
Two animals, one female found dead at Day 15 treated at 100 mg/kg and one male treated at 100 mg/kg at sacrifice showed evidence of enteritis. Both cultured positive for Klebsiella pneumonia. The findings did not adversely affect the evaluation of dermal toxicity of fluometuron.
HISTOPATHOLOGY
The histopathology observations made in both control and treated animals included inflammatory lesions of the kidney, tubular degeneration in the testes. There was also, low grade responsive and inflammatory changes of the skin which were of lower incidence when compared to the control. All of the findings appeared unrelated by incidence and concentration of test substance.
CLINICAL PATHOLOGY
No treatment related changes in haematology or clinical chemistry were detected from blood samples taken prior to sacrifice.

Statistics:

Body weight, organ weight, organ weight ratio, hematology and clinical chemistry data were statistically analyzed for group differences by either analysis or variance or Kruskal-Wallis Test (heterogenous or non-parametric data). Any significant differences were further analyzed using either Tukey´s (equal populations), Scheffe´s (unequal populations) or Kruskal-Wallis Test of Multiple Comparisons. Only significant pairwise comparisons between the control and treated groups were tabulated and discussed.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Description (incidence and severity):

There were no treatment-related effects: One female at a dose level of 100 mg/kg was found dead on Day 15. The death was, believed to be attributed to acute bacterial enteritis and thus unrelated to treatment.

Dermal irritation:

no effects observed

Description (incidence and severity):

No treatment related skin reactions or incidence of erythema or oedema

Mortality:

no mortality observed

Description (incidence):

There were no treatment-related effects: One female at a dose level of 100 mg/kg was found dead on Day 15. The death was, believed to be attributed to acute bacterial enteritis and thus unrelated to treatment.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There was also no difference in overall bodyweight gain between the groups

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

There was also no difference in food consumption between the groups

Ophthalmological findings:

no effects observed

Description (incidence and severity):

There were no treatment-related effects

Haematological findings:

no effects observed

Description (incidence and severity):

There were no treatment-related effects

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

There were no treatment-related effects

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

There were no treatment-related effects

Effect levels

Dose descriptor:

NOEL

Effect level:

1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Table 7.5.3-01: Overview of 21 day repeated dose dermal toxicity in albino rabbits treated with fluometuron technical

Sex	Male				Female
Dose (mg/kg)	0	10	100	1000	0	10	100	1000
Mortality	There were no treatment-related effects*
Bodyweight*	There were no treatment-related effects*
Mean bodyweight (kg) Initial	2.21	2.20	2.19	2.18	2.17	2.19	2.16	2.14
Week 1	2.31	2.35	2.29	2.30	2.29	2.36	2.28	2.25
Week 2	2.42	2.45	2.43	2.41	2.46	2.56	2.37	2.44
Week 3	2.58	2.60	2.55	2.57	2.65	2.73	2.59	2.61
Mean total weight gain (kg)	0.37	0.39	0.36	0.38	0.48	0.54	0.44	0.47
Standard deviation	0.169	0.091	0.148	0.103	0.118	0.099	0.100	0.100
Mean final body weights (kg)	2.4	2.5	2.5	2.4	2.6	2.7	2.5	2.5
Standard deviation	0.21	0.18	0.21	0.13	0.18	0.33	0.19	0.25
Food consumption*
Mean (g/animal/day) Week 1	163.20	173.42	178.27	169.13	173.60	181.44	155.50	152.80
Week 2	169.60	171.53	165.87	172.33	183.67	193.67	131.89	168.67
Week 3	185.33	182.33	154.87	170.60	202.60	201.80	183.33	184.27
Ophthalmology	There were no treatment-related effects
Dermal reactions	No treatment related skin reactions or incidence of erythema or oedema
Clinical pathology (haematology)	There were no treatment related effects
Clinical pathology (clinical chemistry)*	There were no treatment related effects
Organ weights	There were no treatment related effects
Gross necropsy	There were no treatment related effects

*One female in 100 mg/kg treatment group was found dead on Day 15

Applicant's summary and conclusion

Conclusions:

Fluometuron technical does not cause dermal irritation or systemic toxicity in the rabbit when administered for 21 days at doses up to 1000 mg/kg.
Under the conditions of this study the no observed effect level (NOEL) is proposed to be 1000 mg/kg/day

Executive summary:

Fluometuron Technical was evaluated for dermal irritation and systemic toxicity by topical application to the skin of albino rabbits under occlusive bandages for 6 hours/day on twenty-one consecutive days at doses of 10, 100, or 1,000 mg/kg. A concurrent vehicle control group was also evaluated.

One mid-dose female died on study day 15. This death was attributed to an acute bacterial enteritis judged to be unrelated to treatment.

Growth and food intake were unaffected by treatment. No skin reactions were observed that could be attributed to treatment and there were no treatment related changes in hematology or clinical chemistry parameters. No ophthalmoscopic effects were observed.

No significant differences were observed between control and test group organ weight or organ weight ratio data. There were no treatment related gross or microscopic findings.

In conclusion, Fluometuron Technical, when administered at dermal doses of up to 1000 mg/kg, did not produce any dermal irritation or systemic toxicity in the rabbit.