Registration Dossier

Administrative data

Description of key information

subchronic NOAEL = 100 mg/kg bw/d; WoE; read-across from DODMAC, DHTDMAC, DHTDMAMS, DDAC, cetrimonium bromide and cetrimonium chloride

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
sub-chronic toxicity: oral
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Justification for type of information:
REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar toxicological properties because
• they are manufactured from similar or identical precursors under similar conditions
• they share structural similarities with common functional groups: quaternary ammonium and saturated or unsaturated alkyl chains with comparable length (corresponding to scenario 2 of the read-across assessment framework)

The read-across hypothesis is based on structural similarity of target and source substances. Based on available experimental data, including key physicochemical properties and data from acute toxicity, irritation, sensitization (human) and genotoxicity studies, the read-across strategy is supported by a quite similar toxicological profile of all substances.

Therefore, read-across from the existing ecotoxicity, environmental fate and toxicity studies conducted with the source substances is considered as an appropriate adaptation to the standard information requirements of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

A justification for read-across is attached to IUCLID section 13.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See justification for read-across attached to IUCLID section 13.

3. ANALOGUE APPROACH JUSTIFICATION
See justification for read-across attached to IUCLID section 13.

4. DATA MATRIX
See justification for read-across attached to IUCLID section 13.
Reason / purpose:
read-across: supporting information
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Species:
rat
Sex:
male/female
Route of administration:
oral: unspecified
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day (actual dose received)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
clinical signs
body weight and weight gain
Critical effects observed:
no
Conclusions:
A subcronic NOAEL of approx. 100 mg/kg bw/d is expected for Di-C12-18 alkyldimethyl ammonium chloride based on the available data on structurally related substances.
Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
100 mg/kg bw/day
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

No repeated dose toxicity studies are available for the target substance Di-C12-18 alkyldimethyl ammonium chloride. However, experimental data are available for closely related source substances. A justification for read-across is attached to IUCLID section 13.

 

Sub-acute toxicity studies

In a 28-day oral toxicity study, DODMAC (90% active in 5% isopropanol 5% water) was administered by gavage in sesame oil at doses of 0, 20, 100, and 500 mg/kg to Wistar rats. The study was performed according to OECD guideline 407 in compliance with the principles of Good Laboratory Practices. Dosages were calculated on nominal concentration values.

Beginning at the 8th day (females) and 14th day (males) of treatment some high dose animals showed squatting position, abnormal gait, disregular and noisy breathing. Reduced spontaneous activity, retracted flanks and distended abdomen were also seen in some high dose females.

Body weight gain was slightly (non-significantly) lower in high dose males and females compared to the control values.

Hematology revealed significantly reduced reticulocyte counts in high dose males which were within the normal range for this species, sex and age, whereas no other red cell parameter was changed. Mean values for segmented neutrophile ratio were increased in high dose males and females due to abnormal rates in two males and three females. Lower concentrations of albumin and the albumin-globulin ratio and higher gamma-globulin values were observed in males of the high dose group (all changes were significant).

Absolute and relative organ weights of the adrenals were determined to be significantly increased in high dose males. Adrenal weights of high dose females were also higher than controls, however adrenals from three females only were weighted. Macroscopically, enlargement of the adrenals was seen in one female and discoloration of the adrenal surface was evident in three females of the high dose group. Corresponding to these observations in the adrenals, two females had cortical necrosis with peripheral granulocytic infiltration, one of this was hemorrhagic. Furthermore in a single high dose female ulceration of the forestomach was found.

The NOAEL from this study was considered to be 100 mg/kg bw/d.

 

In the 28-day oral gavage study, male and female Sprague-Dawley rats received cetrimonium chloride at 30, 100 and 300 mg/kg bw/day for 5 days/week for 28 days, with additional 28-day recovery groups for the control and high dose. No deaths occurred, no effects were found on food consumption and body weight. The mean water intake of the males of the high dose group was higher than that of controls. Ophthalmologic and hematological results revealed no treatment-related changes in any group. At the high dose, a minor increase in serum ALT activity in males and females (within the range of the historical controls) was found. Males showed a slight increase in absolute and relative adrenal weights and slight decrease in absolute and relative spleen weight, however no histopathological alterations were found in these organs. Upon macroscopic examination thickening of the forestomach mucosa, associated with edema and sporadic ulceration in male and female rats was observed. Microscopic examination revealed inflammatory edema of the forestomach mucosa, sporadic ulceration and acanthosis up to papillomatous hyperplasia in both sexes. No other histopathological abnormalities were found. All treatment-related changes were shown to be reversible following the recovery period. The forestomach and stomach changes observed at 300 mg/kg/day were considered to be a result of local irritation and therefore not indicative of systemic toxicity. The slight weight changes of spleen and adrenals and the increase in serum ALT activity were regarded as a possible sign of some systemic toxicity. Therefore, the dose of 100 mg/kg/day was the NOEL.

 

Sub-chronic toxicity studies

In the 90-day dietary study, male and female Beagle dogs received DHTDMAC at 14, 140 and 2800 ppm (approximately 0.5, 5, 100 mg/kg/d) for 7 days/week for 90 days. No treatment-related effects were observed. Therefore, the NOAEL was >100 mg/kg/day.

Eight purebred beagle dogs (four male and four female) were assigned to three treatment and one control group.

Animals were group housed by sex and dose group. The test substance was incorporated into a stock diet and made available to the dogs three hours per day, seven days a week for 90-days. The control group received the stock diet at the same frequency. At the end of each seven-day period, all unconsumed food was collected and weighed. Food consumption was then calculated and recorded. Body weights were recorded initially then weekly for the duration of the test. The animals were observed daily for clinical signs or symptoms indicative of systemic toxicity.

Hematology, blood chemistry and urinalysis parameters were evaluated in all dogs just prior to test initiation and after 45 and 90 days of testing: At the conclusion of the investigation the dogs were sacrificed and a gross necropsy evaluation was performed.

All major tissues and organs were examined grossly. The weights of the following organs were obtained: liver, kidneys, heart, brain, spleen, gonads, adrenal glands, thyroid gland and pituitary gland. Histopathologic examination were performed on selected tissues from all animals.

No fatalities occurred during the study. Body weight, body weight gains and food consumption were comparable across all groups. There were no treatment related effects noted in urinalysis or hematologic parameters evaluated. A comparison of baseline, 45- and 90-day data revealed no intergroup differences with respect to the blood chemistry parameters evaluated. One male dog receiving 2800 ppm displayed an elevated absolute and relative (to body weight) liver weight. Since this was an isolated incidence and all other test animals displayed normal absolute and relative liver weights, this was not considered related to test material consumption. Also, there were no gross or microscopic lesions observed in the liver of this animal. No other differences in organ weights were noted between dogs in the test and control groups. There were no treatment-related effects noted in the gross or microscopic evaluations. Calcium-like deposits were noted in the lumen of some stomach glands of one low level male dog. Since this was a single incident and did not appear in the higher dose levels it was not considered related to treatment.

 

DHTDMAC was administered to rats in the diet for approximately 4 weeks at dietary levels of 0, 7, 140 and 2800 ppm. These rats were then mated, and a 90-day oral toxicity study was conducted with the offspring at the same dietary levels. No data were presented regarding the parental animals, however it is reported in a letter appended to the report that mating and reproductive performance were normal and all of the offspring were normal. The following data are concerning the offspring in the 90 day feeding study only.

There was a slight depression in weight gain of the treated rats compared to controls, however there was no dose-response relationship. Food consumption was lower for all treated groups compared to controls. It appears that the rats were not the same age at the start of the study and there were large differences in the starting weights (and subsequent weights) because of this, age at study initiation are not included in the report. This may explain the differences in weight gain, and the differences in food consumption as food consumption data were not corrected for body weight.

There were not treatment related mortalities. There were no differences in haematology, clinical chemistry or urinalysis between 2800 ppm rats and controls. Lesions noted at histopathological examination were those of spontaneous disease and not unusual for rats. The most frequent findings were lesions in the trachea and lungs, indicating chronic murine pneumonia. Lesions occurred in both treated and control rats.

Whilst it appears that the 90 day dietary NOAEL is 2800 ppm (approx. 140 mg/kg bw/d), the results should be interpreted with caution.

 

In the 13-week (extended to 21 weeks) dietary study, male and female Sprague-Dawley rats received DHTDMAMS at 0, 0.25, 0.5 and 10% in the diet (0 and approximately 170, 365, and 750 mg/kg/day ingested dose) continuously for 7 days/week for 13 (and 21) weeks. No mortality or significant body weight effects occurred. Increased organ weights of adrenals and liver were observed at all treatment levels. Microscopic evaluation revealed treatment related changes in mesenteric and pulmonary lymph nodes, adrenal glands and liver. Therefore, the LOEL was 170 mg/kg/day.

 

In a 90-day dietary study, male and female dogs received DDAC at 0, 5, 15, or 50 mg/kg/day daily for 90 days. High-dose animals experienced marked decrease in body weight gain, food consumption, and food efficiency, for both males and females. Therefore, the NOAEL was 15 mg/kg/day.

 

In a 90-day dietary study, male and female rats received DDAC at 0, 100, 300, 600, 1000, or 3000 ppm [0, 6.2, 18.5, 36.8, 60.7, or 175.4 mg/kg (males), 0, 7.5, 22.3, 44.4, 74.3, or 225.5 mg/kg/day (females)] continuously for 7 days/week for 90 days. The high dose group showed increased mortality, decrased mean body weight, body weight gain and food consumption. Gross pathology and microscopic examination revealed higher incidence of glycogen depletion in the liver, contracted spleens, sinus erythrocytosis and lymphoid hyperplasia of mesenteric lymph nodes. Therefore, the NOAEL was 1000 ppm, corresponding to 60.7 mg/kg/day in males and 74.3 mg/kg/day in females.

 

Chronic toxicity studies

In a 1-year chronic study male and female Sprague-Dawley rats received cetrimonium bromide in the drinking water at concentrations of 0.007, 0.014 and 0.032 %. These concentrations were calculated to deliver doses of approximately 10, 20 and 45 mg/kg bw/day. Male and female rats of the high dose groups showed a significantly reduced body weight development, decreased efficiency of food conversion, decreased skeletal growth. In both males and females, an increased relative caecum weight was found in the high (males and females) and mid (males only) dose groups. No compound related changes were observed in haematological and clinical-chemical analyses of blood and urine. No gross necropsy changes were seen, and no microscopic alterations were found in the wall of stomach and small intestine of treated rats. No other tissues were histopathologically examined. The effects on growth and body weight development observed in the study are considered to be an indirect effect of the administration of cetrimonium bromide in the drinking water. The detergent caused diarrhoea which resulted in a faster passage of food through the gastrointestinal tract and reduced absorption of nutrients. The increased relative caecum weight may be due to proliferation of the endothelial cell layer caused by an increased replacement rate due to a faster flux of the intestinal contents. This explanation is supported by the lack of histopathologic alterations of the small intestine. In summary, the effects on growth and body weight were most likely caused by a lower nutrients supply, secondary to diarrhoea. The highest dose administered in the study (45 mg/kg bw/day) constitutes a no-observed-adverse-effect-level (NOAEL). The no-observed-effect-level (NOEL) was 10 mg/kg bw/day.

 

Conclusion

Based on the acute toxicity studies, DDAC seems to exhibit a considerably higher toxicity compared to the target substance as well as to the source substances DODMAC and DHTDMAC. This trend may also be recognized in the available repeated dose toxicity studies. Especially the subchronic dietary study in beagle dogs conducted with DDAC, a markedly lower NOAEL of 15 mg/kg bw/d was found compared to other subchronic studies, in which NO(A)ELs of approx. 100 mg/kg bw/d. No further details on the subchronic study in beagles with DDAC are available, thus, this study is assigned a reliability of 4. Moreover, DHTDMAC was not more toxic to dogs than to rats. Thus, the subchronic study in beagles conducted with DDAC is considered an outlier.

The chronic study in rats conducted with cetrimonium bromide resulted in a NOAEL of 45 mg/kg bw/d, which was the highest administered dose; the true NOAEL may be higher.

On the basis of the available studies, the subchronic NOAEL of Di-C12-18 alkyl-dimethyl ammonium chloride is expected to lie between 140 and 170 mg/kg bw/d. Using a NOAEL of 100 mg/kg bw/d asa starting point for DNEL derivation is a sufficiently conservative approach.

There are no data gaps for the endpoint repeated dose toxicity. No human data are available. However, there is no reason to believe that these results from rat and rabbits would not be applicable to humans.

For the derivation of DNELs the selection of a subchronic NOAEL of 100 mg/kg bw/d or a chronic NOAEL of 45 mg/kg bw/d as starting points and applying a time extrapolation factor of 2 (subchronic study) or 1 (chronic study) will not result in relevant differences. Furthermore, conservative assessment factors will be applied for the derivation of worker and general population DNELs.

Justification for classification or non-classification

Based on the available data, the target substance Di-C12-18 alkyl-dimethyl ammonium chloride does not need to be classified and labelled according to the CLP Regulation (EC) No 1272/2008 with respect to repeated dose toxicity.