Naphthenic acids, zinc salts

Endpoint summary

Description of key information

The acute oral toxicity of naphthenic acids, zinc salts, neutral, was evaluated in a GLP-compliant study following OECD guideline 423. 6 female rats were exposed to a single dose by oral gavage and no effects were observed. Therefore, the oral LD50 value in Wistar rats was established to exceed 2000 mg/kg body weight. According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight. Based on these results, the substance does not meet the criteria for classification under EU CLP.

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

Study period:

08 January 2018 - 30 January 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

December 2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA Health Effects Test Guideline OPPTS 870.1100. Acute Oral Toxicity in Rodents, December 2002.

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EC No 440/2008 Part B. Acute Oral Toxicity, Acute Toxic Class Method, May 2008.

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Appendix to Director General Notification, No. 12-Nousan-8147. Agricultural Production Bureau, Ministry of Agriculture, Forestry and Fisheries of Japan (JMAFF), November 2000, including the most recent revisions.

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Specific details on test material used for the study:

- Source and lot/batch No. of test material: A036/99 (Supplier batch number: SCC-1709-0300)
- Expiration date of the lot/batch: 31 August 2018
- Storage condition of test material: Room temperature

Species:

rat

Strain:

other: Wistar Han

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Outbred, SPF-Quality, by Charles River Deutschland, Sulzfeld, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: Young adult animals (approximately 10-11 weeks old) were selected.
- Weight at study initiation: 187 to 211 g.
- Fasting period before study: Animals were deprived of food overnight (for a maximum of 20 hours) prior to dosing and until 3-4 hours after administration of the test item. Water was available.
- Housing: On arrival and following assignment to the study, animals were group housed (up to 3 animals of the same sex and same dosing group together) in polycarbonate cages (Makrolon MIV type; height 18 cm.) containing sterilized sawdust as bedding material (Lignocel S 8-15, JRS - J.Rettenmaier & Söhne GmbH + CO. KG, Rosenberg, Germany) equipped with water bottles. The room(s) in which the animals were kept were documented in the study records. Animals were separated during designated procedures/activities. Each cage was clearly labelled.
- Diet: Pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany) was provided ad libitum throughout the study, except during designated procedures.
- Water: Municipal tap-water was freely available to each animal via water bottles.
- Acclimation period: The animals were allowed to acclimate to the Test Facility toxicology accommodation for at least 5 days before the commencement of dosing.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Target temperatures were 18 to 24°C. The actual daily mean temperature during the study period was 20 to 21°C.
- Humidity (%): Relative target humidity was 40 to 70%. The actual daily mean relative humidity was 41 to 50%.
- Air changes (per hr): Ten or greater air changes per hour with 100% fresh air (no air recirculation).
- Photoperiod (hrs dark / hrs light): A 12-hour light/12-hour dark cycle was maintained.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: Formulation of 200 mg/mL test item in corn oil
- Stability in vehicle: Analysis of test item in vehicle for concentration, stability, homogeneity was not performed.
- Supplier: Fagron, Nieuwerkerk a/d IJssel, The Netherlands
- Specific gravity of vehicle: 0.92. Adjustment was made for specific gravity of the vehicle. No correction was made for the purity/composition of the test item.
- Rationale for vehicle: Trial preparations were performed at the Test Facility to select the suitable vehicle and to establish a suitable formulation procedure. Trial preparation formulations were not used for dosing and were discarded after the assessment is complete. These trial preparations have a non-GLP status and were carried out in the quality assured environment of the Test Facility.

MAXIMUM DOSE VOLUME APPLIED: Dose volume of 10 mL/kg body weight

DOSAGE PREPARATION: Test item dosing formulations (w/w) were homogenized to visually acceptable levels at appropriate concentrations to meet dose level requirements. In order to obtain homogeneity, the test item dosing formulations were heated in a water bath at approximately 60ºC for approximately 15 minutes. The test item formulations were allowed to cool to a temperature of maximally 40ºC prior to dosing. The dosing formulations were kept at room temperature until dosing. The dosing formulations were stirred until and during dosing.

DOSAGE ADMINISTRATION: A single dose of test item was administered to the appropriate animals by oral gavage on Day 1, using a syringe with a plastic gavage cannula attached. The dose volume for each animal was based on the body weight measurement prior to dosing. The dosing formulations were stirred continuously during dose administration.

CLASS METHOD
- Rationale for the selection of the starting dose: The oral route was selected as it is a possible route of human exposure during manufacture, handling or use of the test item. The dose levels were based on the OECD test guidelines and were selected from the series 5 (lowest dose level), 50, 300 and 2000 (highest dose level) mg/kg body weight. The starting dose level should be the one that is likely to produce mortality in at least some of the animals and was selected based on available toxicity data of the test item.
- Rationale for the dosing regime: The toxicity of the test item was assessed by stepwise treatment of groups of 3 females. The absence or presence of mortality of animals dosed at one step determined the next step, based on the test procedure defined in the guidelines. The onset, duration and severity of the signs of toxicity were taken into account for determination of the time interval between the dose groups. The first group was treated at a dose level of 2000 mg/kg. Based on the results, one additional group was dosed at 2000 mg/kg.

Doses:

Total dose of 2000 mg/kg test item

No. of animals per sex per dose:

6 females per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: Postdose observations were performed at periodic intervals on the day of dosing (at least three times) and once daily thereafter. The observation period was 14 days.
- Frequency of observations: Throughout the study, animals were observed for general health/mortality and moribundity twice daily, in the morning and at the end of the working day. Animals were not removed from cage during observation, unless necessary for identification or confirmation of possible findings.
- Observations: All the animals were examined for reaction to dosing. The onset, intensity and duration of these signs was recorded (if appropriate). Signs were graded for severity and the maximum grade was predefined at 3 or 4. Grades were coded as slight (grade 1), moderate (grade 2), severe (grade 3) and very severe (grade 4). For certain signs, only its presence (grade 1) or absence (grade 0) was scored.
- Weighing: Animals were weighed individually on Day 1 (predose), 8 and 15. A fasted weight was recorded on the day of dosing.
- Necropsy of survivors performed: yes
- Examinations performed: All moribund animals and animals surviving to the end of the observation period were sacrificed by oxygen/carbon dioxide procedure. All animals assigned to the study were subjected to necropsy and descriptions of all internal macroscopic abnormalities were recorded.

Statistics:

The oral LD50 value of the test item was ranked within the following ranges: 0-5, 5-50, 50-300 or 300-2000 mg/kg b.w. or as exceeding 2000 mg/kg b.w. The LD50 cut-off value was established based on OECD guideline 423. No statistical analysis was performed (The method used is not intended to allow the calculation of a precise LD50 value).
The results were evaluated according to: Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments); Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of items and mixtures (including all amendments).

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No mortality occurred.

Clinical signs:

Hunched posture, uncoordinated movements and piloerection were noted for the animals between Days 1 and 4. In addition, salivation was noted for one animal on Day 1.

Body weight:

The mean body weight gain shown by the animals over the study period was considered to be similar to that expected for normal untreated animals of the same age and strain. The incidence of slight body weight loss on Day 15 in one animal was considered not indicative of toxicity, based on the absence of any corroborative findings in this animal.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Other findings:

The oral LD50 value in Wistar rats was established to exceed 2000 mg/kg body weight. According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight.
Based on these results, the substance does not have to be classified and has no obligatory labelling requirement for acute oral toxicity according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).

Interpretation of results:

GHS criteria not met

Conclusions:

The oral LD50 value in Wistar rats was established to exceed 2000 mg/kg body weight. According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight. Based on these results, the substance does not meet the criteria for classification under EU CLP or GHS.

Executive summary:

The acute oral toxicity of naphthenic acids, zinc salts, neutral, was evaluated in a GLP-guideline study following OECD guideline 423. 6 female rats were exposed to a single dose by oral gavage and no effects were observed. Therefore, the oral LD50 value in Wistar rats was established to exceed 2000 mg/kg body weight. According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight. Based on these results, the substance does not meet the criteria for classification under EU CLP or GHS.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Guideline study

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The oral LD50 value in Wistar rats was established to exceed 2000 mg/kg body weight. According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight. Based on these results, the substance does not meet the criteria for classification under EU CLP.