2-hydroxymethyl-9-methyl-6-(1-methylethyl)-1,4-dioxaspiro[4.5]decane

Endpoint summary

Description of key information

Both the dermal and the oral LD50 value of the test substance in rats of either sex are exceeding 2000 mg/kg body weight.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented study according to GLP and following OECD guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

HUSBANDRY

Room Number: 13

Conditions:
Standard Laboratory Conditions. The room was air-conditioned with 15 air changes per hour and the environment controlled with optimal conditions
410 considered as being a temperature of 21°C and a relative humidity of 55%. Occasional fluctuations from these optimal conditions were noted, but were considered not to have affected study integrity. Lighting was 12 hours artificial fluorescent light and 12 hours dark per day.

Accommodation
Group housed, five per sex to a cage, using polycarbonate cages containing purified sawdust as bedding material (Woody SPF, supplied by Broekman
Institute, Someren, The Netherlands). Certificates of sawdust analysis were examined and then retained in the RCC NOTOX archives.

Diet
Free access to standard pelleted laboratory animal diet (Kliba 343 from Klingentalmühle AG, Kaiseraugst, Switzerland). Certificates of analysis were examined and then retained in the RCC NOTOX archives.

Water
Free access to tap-water. Certificates of analysis (performed quarterly) were examined and then retained in the RCC NOTOX archives.

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

Fasting: Feed was withheld overnight prior to dosing until approximately 3-4 hours after administration of the test substance.

Frequency: Once, on day 1.

Doses:

Dose level
Group 1: 5000 mg/kg body weight.
Group 2: 3750 mg/kg body weight.
Group 3: 2800 mg/kg body weight.

Dose level:
Group 1: 4.8 ml/kg body weight.
Group 2: 3.6 ml/kg body weight.
Group 3: 2.7 ml/kg body weight.
Calculated as follows:
dose level (g/kg): specific gravity (g/ml). The specific gravity used was 1.04 g/ml.

No. of animals per sex per dose:

5

Details on study design:

DOSE SELECTION
Initially a "Limit study" with the test substance at a dose level of 5000 mg/kg body weight was performed. Due to the mortality and signs of toxicity noted among animals receiving 5000 mg/kg body weight, two further groups were selected for the "Full study" and dosed at 3750 and 2800 mg/kg body weight.

OBSERVATIONS
Mortality / Viability:
At periodic intervals on the day of dosing (day 1) and twice daily thereafter for 14 days.

Body Weights:
Days 1 (pre-administration), 8 and 15 and at death (if found dead after day 1).

Symptoms:
At periodic intervals on the day of dosing (day 1) and once daily thereafter for 14 days. All signs of reaction to treatment were recorded with particular attention paid to changes in the skin, fur, eyes and mucous membranes, as well as to behaviour pattern, tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.

PATHOLOGY
Necropsy:
All animals surviving to the end of the observation period were sacrificed by oxygen/carbon dioxide asphyxiation. All animals assigned to the study were subjected to necropsy and descriptions of all macroscopic abnormalities recorded.

Statistics:

The LD50 values and the associated 95% confidence interval, the slope of the dose mortality curve were calculated using the Maximum likelihood method (Finney, D.J. Probit Analyses, 3rd Edn., Cambridge University Press, 1971).

Sex:

male/female

Dose descriptor:

LD50

Effect level:

5 716 mg/kg bw

Based on:

test mat.

Mortality:

The following mortality rates were observed:
Dose level Males Females Sexes Combined
5000 mg/kg 2/5 2/5 4/10
3750 mg/kg 0/5 0/5 0/10
2800 mg/kg 0/5 0/5 0/10

Gross pathology:

5000 mg/kg body weight: Irregular areas in forestomach.
3750 mg/kg body weight: Irregular areas in forestomach.
2800 mg/kg body weight: No abnormalities.

Other findings:

All surviving animals treated at 5000 mg/kg body weight had recovered by day 4. All animals treated at 3750 and 2800 mg/kg body weight had recovered by day 3 and 2, respectively.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The oral LD50 value of the test substance in rats was 5716 mg/kg body weight for the males only and for the females only. Due to the mortality distribution, only an estimated oral LD50 value of HR 91/917 247 could be calculated for the males and females combined. The estimated LD50 value for the sexes combined was 5716 mg/kg body weight.

Executive summary:

The purpose of this study was to assess the toxicity of the test article when administered to rats as a single oral dose. The study was carried out in accordance with OECD Guideline No. 401, "Acute Oral Toxicity" and EEC Directive 84/449/EEC, Part B.1, "Acute Toxicity-Oral". The test substance was administered by oral gavage to five rats of each sex per group, at 5000, 3750 or 2800 mg/kg body weight. Macroscopic examination was performed at the end of the experimental period. The incidence of mortality among the sexes combined from high to low dose group, was 4, 0 and 0. Major changes in clinical appearance included lethargy, no reaction to external stimuli, bradypnoea, piloerection and ataxia. All surviving animals treated with 5000 mg/kg body weight had recovered by day 4. Animals treated with 3750 and 2800 mg/kg body weight had recovered by day 3 and 2, respectively. Animals of the 5000 mg/kg body weight group, which were found dead between day 2-5, showed body weight loss an the day of death. The body weight gain shown by all surviving animals over the study period was considered to be similar to that expected of normal untreated animals of the same age and strain. Macroscopic post mortem examination of the animals that died during the study revealed yellow fluid contents of the stomach and grey-green areas in the forestomach. Macroscopic post mortem examination of the surviving animals at termination revealed irregular areas in the forestomach. The oral LD50 value for male or female rats alone, treated with the test substance, was 5716 mg/kg body weight. Due to the mortality distribution, only estimated oral L050 values of the test substance could be calculated for males and females combined and amounted to 5716 mg/kg body weight. Based an these results,the substance should not be classified as acute toxic according to the criteria described in EU Regulation No. 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures (CLP).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

5 716 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented study according to GLP and following OECD guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

HUSBANDRY
Room number: 12.
Conditions
Standard Laboratory Conditions. The room was air-conditioned with 15 air changes per hour and the environment controlled with optimal conditions
considered as being a temperature of 21°C and a relative humidity of 55%. Occasional fluctuations from these optimal conditions were noted, but were considered not to have adversely affected study integrity. Lighting was 12 hours artificial fluorescent light and 12 hours dark per day.

Accomodation
Individually housed in polycarbonate cages containing purified sawdust as bedding material (Woody SPF, supplied by Broekman Institute, Someren, The Netherlands). Certificates of analysis were examined and then retained in the RCC NOTOX archives.

Diet
Free access to standard pelleted laboratory animal diet (Kliba 343 from Klingentalmühle AG, Kaiseraugst, Switzerland). Certificates of analysis were examined and then retained in the RCC NOTOX archives.

Water
Free access to tap-water. Certificates of analysis (performed quarterly) were examined and then retained in the RCC NOTOX archives.

Vehicle:

petrolatum

Details on dermal exposure:

The formulation was applied to an area of approximately 25 cm 2( 5x5 cm) for males and 18 cm 2( 3.5x5 cm) for females by application on a gauze patch fixed successively to aluminium foil and flexible bandage (Coban, 3M, St. Paul, U.S.A.), with drops of petrolatum.

Duration of exposure:

24 hours, whereafter residual test substance was removed with tissue moistened with tap-water.

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

OBSERVATIONS

Mortality / Viability
At periodic intervals on the day of dosing (day 1) and twice daily thereafter for 14 days.

Body Weights
Days 1 (pre-administration), 8 and 15.

Clinical signs
At periodic intervals on the day of dosing (day 1) and once daily thereafter for 14 days. All signs of reaction to treatment were recorded with
particular attention paid to changes in the skin (treated skin), fur, eyes and mucous membranes, as well as to behaviour pattern, tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.


PATHOLOGY
Necropsy
All animals surviving to the end of the observation period were sacrificed by
oxygen/carbon dioxide asphyxiation and subjected to necropsy. Descriptions of
all macroscopic abnormalities were recorded.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

No mortality occurred during the study period.

Clinical signs:

other: No signs of ill health or behavioural changes were observed.

Gross pathology:

Macroscopic post mortern examination of the surviving animals at termination revealed no abnormalities that were considered to have arisen as an effect of treatment. A light-brown appearance of the processus papillaris in the liver, as noted in one male, was considered not to be treatment related.

Other findings:

In the majority of the animals, scales and erythema were observed an the treated skin area an days 4-7.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The dermal LD50 value of the test substance in rats of either sex was established as exceeding 2000 mg/kg body weight.

According to the EEC criteria for classification and labelling requirements for dangerous substances (EEC Directive 83/467/EEC, Annex VI of the EEC
Directive 67/548/EEC), the test substance does not need to be classified and has no obligatory labelling requirement.

Executive summary:

The purpose of this study was to assess the toxicity of the test article when administered to rats as a single dermal dose. The study was carried out in accordance with OECD Guideline No. 402, "Acute Dermal Toxicity" and EEC Directive 84/449/EEC, Part B.3, "Acute Toxicity - Dermal". The test substance was administered by dermal application, to five rats of each sex, at 2000 mg/kg body weight. Macroscopic examination was performed at the end of the experimental period. No animals died during the study. No signs of ill health or behavioural changes were observed. The body weight gain shown by the animals over the study period was considered to be similar to that expected of normal untreated animals of the same age and strain. In the majority of animals, scales and erythema were noted on the treated skin area on days 4-7. Macroscopic post mortem examination of the surviving animals at termination revealed no abnormalities that were considered to have arisen as an effect of treatment. The dermal LD50 value of the test substance in rats of either sex was established as exceeding 2000 mg/kg body weight. Based on these results results,the substance should not be classified as acute toxic according to the criteria described in EU Regulation No. 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures (CLP).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

A total of four studies (two for dermal and two for oral toxicity) are available that assess the acute toxicity of the test substance. All four studies were performed according to GLP and internationally accepted guidelines.

ACUTE TOXICITY ORAL 

The key study (Reijnders, 1991) reported an oral LD50 value of the test substance in rats of 5716 mg/kg body weight for the males only and for the females only. Due to the mortality distribution, only an estimated oral LD50 value of the test substance could be calculated for the males and females combined. The estimated LD50 value for the sexes combined was 5716 mg/kg body weight as well.

In a supporting study by Skydsgaard, 1991 an oral LD50 value of > 2000 mg/kg body weight was reported in a limit study. No rats died and no other adverse effects were detected.

ACUTE TOXICITY DERMAL

The key study (Reijnders, 1991) reported no mortality during the study. No signs of ill health or behavioural changes were observed. The body weight gain shown by the animals over the study period was considered to be similar to that expected of normal untreated animals of the same age and strain. In the majority of animals, scales and erythema were noted on the treated skin area on days 4-7. Macroscopic post mortem examination of the surviving animals at termination revealed no abnormalities that were considered to have arisen as an effect of treatment. The dermal LD50 value of the test substance in rats of either sex was established as exceeding 2000 mg/kg body weight.

In a supporting study by Skydsgaard, 1991 an oral LD50 value of > 2000 mg/kg body weight was reported as well. No rats died and no other adverse effects were detected.

Justification for selection of acute toxicity – oral endpoint
Well documented study according to GLP and internationally accepted guidelines.

Justification for selection of acute toxicity – dermal endpoint
Well documented study according to GLP and internationally accepted guidelines.

Justification for classification or non-classification

Based on the acute toxicity results, showing LD50 values > 5000 mg/kg bw for oral administration and > 2000 mg/kg bw for dermal administration, the substance should not be classified as acute toxic or STOT-SE according to the criteria described in EU Regulation No. 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures (CLP) or Directive 67/548/EEC (Dangerous Substances Directive).