Hexadecyl hydrogen maleate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and no systemic effects have been observed in in vivo studies with dermal exposure (e.g. skin irritation, skin sensitisation)

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May 16th to June 10th, 2019

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:

adopted on 17 December 2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: In-house bred animals
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 9 weeks
- Weight at study initiation: 168.21 g to 178.44 g
- Fasting period before study: overnight (16 to 18 hours) prior to dosing. Feed was offered 3 to 4 hours after dosing
- Housing: groups of 3 in standard polypropylene cage (Size: L 430 x B 285 x H 150 mm) with stainless steel mesh top grill. Clean sterilized paddy husk was provided as bedding material
- Diet: ad libitum. Altromin Maintenance diet for rats and mice (manufactured by Altromin Spezialfutter GmbH & Co. KG)
- Water: ad libitum. Dee bore-well water passed through reverse osmosis unit was providded in plastic water bottles with stainless steel sipper tubes
- Acclimation period: Healthy young adult animals used for Step-I, Step-I confirmation, Step-II and Step-II confirmation were acclimatized for five, six, eight and eleven days respectively to laboratory condition prior to treatment and were observed for clinical signs once daily. Veterinary examination of all the animals was performed on the day of receipt and on 5th day of acclimatization.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.2°C to 23.4°C
- Humidity (%): 43% to 63%
- Air changes (per hr): 12 to 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours fluorescent light and 12 hours dark cycle

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5% w/v Carboxy methyl cellulose

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 0.5 % CMC in distilled water
- Justification for choice of vehicle: as per the in-house stability test, test item forms supsension in 0.5 % w/v CMC. Hence 0.5 % w/v CMC was selected as vehicle
- Lot/batch no. (if required): BCBNI690V

MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg bw

DOSE FORMULATION
Required quantity of test item was weighed as per the dose. The weighed test item was grounded well by using a pestle and mortar by adding a small quantity of vehicle and then transferred to a measuring cylinder. Again, a small quantity of vehicle was added and transferred to the measuring cylinder. The procedure was repeated until the complete transfer of the test item into the measuring cylinder. The final volume was adjusted to required mark with vehicle in the measuring cylinder to get desired concentration.
Freshly prepared test item formulation was used for dosing. The homogeneity of the test item formulation was maintained by continuous stirring on a magnetic stirrer during dosing.

Doses:

300 and 2000 mg/kg bw

No. of animals per sex per dose:

3 per step

Control animals:

no

Details on study design:

The animals were dosed in a stepwise procedure with three female animals per step. As the LD50 of the test item was not available a starting dose of 300 mg/kg body weight was selected from the fixed dose levels of 5, 50, 300 and 2000 mg/kg body weight. The test item was administered by oral gavage as a single dose of 300 mg/kg body weight to three female rats in Step-I. No clinical signs of toxicity and mortality was observed at 300 mg/kg body weight in Step-I. Hence, as per the decision rules governing the sequential procedure presented in the OECD 423 test guideline, Step-I confirmation was conducted using three more female rats approximately after 24 hours of observation by administering a single dose of 300 mg/kg body weight of the test item. No clinical signs of toxicity and mortality was observed at 300 mg/kg body weight in Step-I confirmation. Hence, as per the decision rules governing the sequential procedure presented in the OECD 423 test guideline, Step-II was conducted using three more female rats approximately after 48 hours of observation by administering a single dose of 2000 mg/kg body weight. No clinical signs of toxicity and mortality was observed at 2000 mg/kg body weight in Step-II. Hence, as per the decision rules governing the sequential procedure presented in the OECD 423 test guideline, Step-II confirmation was conducted using three more female rats approximately after 72 hours of observation by administering a single dose of 2000 mg/kg body weight of the test item. No clinical signs of toxicity and no mortality was observed at 2000 mg/kg body weight in Step-II confirmation.
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: at 20 to 30 min, 1 hr (±10 mins), 2 hrs (±10 mins), 3 hrs (±10 mins) and 4 hrs (±10 mins) post dosing on Day 1 and once daily thereafter for clinical signs of toxicity and twice daily for mortality during the 14 days observation period. Body weight was recorded on day 1 before test item administration and on day 8 and 15 during the observation period.
- Necropsy of survivors performed: yes. At the end of observation period (on day 15), all the surviving animals were humanely sacrificed by carbon dioxide asphyxiation, subjected to necropsy and a complete gross pathological examination and the observations were recorded
- Examinations performed: clinical signs, body weight, pathology. Observations included changes in skin, fur, eyes and mucous membranes and also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern. A special attention was directed to observations of tremors, convulsion, salivation, diarrhea, lethargy, sleep and coma. No animals were in pain or showing severe signs of distress or in moribund conditions.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

None

Clinical signs:

No clinical signs of toxicity were observed in any of the doses

Body weight:

No changes were observed and percent change in body weight with respect to day 1. All the surviving animals presented a physiological increase in body weight.

Gross pathology:

No gross pathological changes were observed in any of the animals

Interpretation of results:

other: not classified as harmful/toxic according to the CLP Regulation (EC) No.1272/2008

Conclusions:

LD50 (female rats) > 2000 mg/kg bw

Executive summary:

The test item was evaluated for acute oral toxicity in Sprague Dawley rats as per OECD Guideline No. 423.

A starting dose of 300 mg/kg body weight was selected from the four fixed dose levels of 5, 50, 300 and 2000 mg/kg body weight, since no information was available about the test item.

A total of 12 females (3 females for each Step-I, Step-I confirmation and Step-II, Step-II confirmation) were used for the experiment. All the animals of Step-I and  Step-I confirmation were administered with 300 mg/kg body weight of the test item and Step II  and Step II confirmation were administered with 2000 mg/kg body weight of the test item by oral route. All the animals were observed for clinical signs of toxicity and mortality. At the end of observation period, all the surviving animals were humanely sacrificed by carbon dioxide asphyxiation, subjected to necropsy and gross pathological examination. In Step-I and Step-I confirmation, the animals were dosed with 300 mg/kg body weight did not reveal any clinical signs of toxicity and mortality. In Step-II and Step-II confirmation, the animals dosed with 2000 mg/kg body weight did not reveal any clinical signs of toxicity and mortality.

The rats were observed for 14 days for clinical signs of toxicity and were subjected to necropsy at the end of the observation period.

No changes were observed in body weight and percent change in body weight with respect to day 1 at 300 mg/kg body weight and 2000 mg/kg body weight. All the surviving animals revealed physiologically normal increase in the body weight.

No gross pathological changes were observed in any of the surviving animals at 300 mg/kg body weight and 2000 mg/kg body weight.

Conclusion

Based on the results of the experiment, it is concluded that the LD50 cut off value for the test item is 5000 mg/kg body weight and classified as “Category 5 or unclassified (2000 < ATE ≤ 5000 mg/kg body weight)” as per the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).

The LD50 is considered to be > 2000 mg/kg bw