N,N-bis(2-hydroxyethyl)dodecanamide

Carcinogenicity

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Link to relevant study records

Reference

Reference 1

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not available

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Principles of method if other than guideline:

A two-year dermal study was conducted in mice to evaluate the carcinogenic potential of the test substance.

GLP compliance:

yes

Species:

mouse

Strain:

B6C3F1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Taconic Farms, Germantown, NY
- Age at study initiation: 6 wk
- Housing: Housed individually in Polycarbonate , changed weeklyand rotated every 2 wk
- Diet : NIH-07 open formula pelleted diet, ad libitum
- Water : Tap water via automatic watering system available cleaned every 2 wk, ad libitum
- Acclimation period: 13 d (males); 14 d (females)

ENVIRONMENTAL CONDITIONS
- Temperature : 20.5-26.1°C
- Humidity : 33-64%
- Air changes : 10/hr
- Photoperiod : 12 h dark/12 h light

IN-LIFE DATES: From: Dec. 30, 1992 To: Jan. 06, 1995

Route of administration:

dermal

Vehicle:

ethanol

Details on exposure:

VEHICLE
Purity: ranged from 97 to 103% relative to the reference standard

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Dose preparations were analysed approximately every 2 months using HPLC. All dose formulations analysed during the 2-yr studies were within 10% of the target concentration. In addition to dose formulation analysis prior to dosing, samples collected after dosing (animal room samples) were analysed periodically.

Duration of treatment / exposure:

105-106 wk

Frequency of treatment:

Five exposures per week

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

100 mg/kg bw/day (nominal)

Remarks:

corresponding to 50 mg/mL in ethanol

Dose / conc.:

200 mg/kg bw/day (nominal)

Remarks:

corresponding to 100 mg/mL in ethanol

No. of animals per sex per dose:

50/sex/dose

Control animals:

yes, concurrent vehicle

Details on study design:

Dose selection rationale: Dose selection was based primarily on the increased incidences of a spectrum of skin lesions at the site of application. Doses of 400 or 800 mg/kg bw were associated with high incidences of chronic inflammation and ulceration and were thus considered to be inappropriate for a 2-yr study. A marked reduction in toxic response occurred at 200 mg/kg bw, and 100 mg/kg bw was a no-effect level in male mice. Therefore, 200 mg/kg bw was selected as the high dose for the 2-yr study and 100 mg/kg bw as the low dose.

Positive control:

No

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: At study initiation, at 4-wk intervals during the study, and at necropsy

DERMAL IRRITATION (if dermal study): Yes

BODY WEIGHT: Yes
- Time schedule for examinations: Animals were weighed initially at study initiation, weekly during weeks 1-13, at 4-wk intervals thereafter, and at the end of the study.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: No

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

METHOD OF SACRIFICE: Carbon dioxide asphyxiation

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes, Complete histopathology was performed on all animals. In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone and marrow, brain, clitoral gland, esophagus, heart, large intestine (cecum, colon, rectum), small intestine (duodenum, jejunum, ileum), kidney, liver, lung, lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin, spleen, stomach (forestomach and glandular), testis (and epididymis and seminal vesicle), thymus, thyroid gland, trachea, urinary bladder, and uterus.

Other examinations:

None

Statistics:

Survival Analyses: The probability of survival was estimated by the product-limit procedure of Kaplan and Meier (1958). Possible dose-related effects on survival were analysed by Cox’s (1972) method for testing two groups for equality and Tarone’s (1975) life table test to identify dose-related trends. All reported P values for the survival analyses were two sided.

Analysis of Neoplasm and Nonneoplastic Lesion Incidences: The Poly-k test (Bailer and Portier, 1988; Portier and Bailer, 1989; Piegorsch and Bailer, 1997) was used to assess neoplasm and nonneoplastic lesion prevalence. Tests of significance included pairwise comparisons of each dosed group with controls and a test for an overall dose-related trend. Continuity-corrected tests were used in the analysis of lesion incidence, and reported P values are one sided.

Clinical signs:

no effects observed

Description (incidence and severity):

No significant difference in clinical findings was observed between the dosed groups and the vehicle control groups.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No significant difference in survival was observed between the dosed groups and the vehicle control groups.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No significant difference was observed in the mean body weights between the dosed groups at 100 mg/kg bw and the vehicle control groups. The mean body weight of females that received 200 mg/kg bw was 94% that of the vehicle controls by week 33 and remained lower throughout the remainder of the study.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Liver: The incidences of hepatocellular adenoma or carcinoma (combined) were significantly increased in dosed female groups compared to that in the vehicle control group, as was the incidence of hepatocellular adenoma in 100 mg/kg bw females. These incidences exceeded the historical control ranges for these neoplasms. There were also increases in the incidences of eosinophilic foci in dosed female mice, and the increase was significant in females at 200 mg/kg bw. The incidences of hepatocellular adenoma, carcinoma, and adenoma or carcinoma (combined) were not significantly increased in dosed male mice. These increases were associated with free diethanolamine, which was present as a contaminant of lauric acid diethanolamine condensate.

Thyroid Gland: Incidences of focal hyperplasia of thyroid gland follicular cells were increased in dosed male mice; the incidence in the 200 mg/kg bw group was significantly greater than that in the vehicle control group. There were no corresponding increases in the incidences of follicular cell neoplasms.

Histopathological findings: neoplastic:

no effects observed

Description (incidence and severity):

Skin, site of application: Incidences of nonneoplastic lesions of the skin at the site of application were significantly increased in dosed males and females. The lesions were of minimal to moderate severity and consisted mostly of thickening of the epidermis (epidermal hyperplasia) and sebaceous gland hyperplasia. Compared to the vehicle controls, the incidences of chronic inflammation and hyperkeratosis were significantly greater in all groups of dosed males and females, and the incidences of parakeratosis were significantly greater in males and females administered 200 mg/kg bw. Ulcers occurred in a few mice at 200 mg/kg bw and were indicative of more severe local irritation.

Other effects:

not examined

Relevance of carcinogenic effects / potential:

Yes

Key result

Dose descriptor:

NOAEL

Sex:

male/female

Remarks on result:

not determinable

For detailed results tables kindly refer to the attached background materials section of the IUCLID.

Conclusions:

Under the study conditions, no evidence of carcinogenic activity was reported in male mice. Some evidence of carcinogenic activity in female mice based on increased incidence of hepatocellular neoplasms was associated with free diethanolamine (DEA), which was present as a contaminant of the test substance.

Executive summary:

A study was conducted to evaluate the long-term repeated dose dermal carcinogenicity in B6C3F1 mice of the test substance, C12 DEA, in compliance with GLP. Groups of 50 male and 50 female mice were exposed to dermal doses equivalent to 0, 100 or 200 mg/kg/day, 5 d/week, for 105-106 weeks. The animals were observed twice daily. Body weights and clinical findings were recorded periodically. Necropsy and complete histopathology was performed on all animals at test end. Mean body weights of females in 200 mg/kg bw/day dose group were lower than those of the vehicle controls beginning at week 33. The incidences of hepatocellular adenoma or carcinoma (combined) were significantly increased in treated females compared to the vehicle controls, as was the incidence of hepatocellular adenoma in the100 mg/kg bw/day female group. There were dose-related increases in the incidences of non-neoplastic lesions of the skin at the site of application, including epidermal and sebaceous gland hyperplasia, hyperkeratosis, chronic inflammation, and parakeratosis. Treated males had greater incidences of thyroid gland follicular cell focal hyperplasia than did the vehicle controls; the incidence in the 200 mg/kg bw/day group was significantly greater than that in the vehicle control group. Under the study conditions, no evidence of carcinogenic activity was reported in male mice. Some evidence of carcinogenic activity in female mice based on increased incidence of hepatocellular neoplasms was associated with free diethanolamine (DEA), which was present as a contaminant of the test substance (NTP, 1999). However, recent evidence suggests that DEA should not be classified as a carcinogen, as the hepatic tumours seen in mice and the proposed mode of non-genotoxic mechanism are not relevant to humans/primates.

Reference 2

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not available

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Principles of method if other than guideline:

A two-year dermal study was conducted in rats to evaluate the carcinogenic potential of the test substance.

GLP compliance:

yes

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Taconic Farms, Germantown, NY
- Age at study initiation: 6 wk
- Housing: Housed individually in Polycarbonate , changed weekly and rotated every 2 wk
- Diet : NIH-07 open formula pelleted diet, ad libitum
- Water : Tap water via automatic watering system, ad libitum
- Acclimation period: 11 d (males); 12 d (females)

ENVIRONMENTAL CONDITIONS
- Temperature : 21.1-26.7°C
- Humidity : 36-59%
- Air changes : 10/h
- Photoperiod : 12 h dark/12 h light

IN-LIFE DATES: From: Dec. 14, 1992 To: Dec. 14, 1994

Route of administration:

dermal

Vehicle:

ethanol

Details on exposure:

VEHICLE
Purity: ranged from 97% to 103% relative to the reference standard

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Dose preparations were analysed approximately every 2 m using HPLC. All dose formulations analysed during the 2-yr studies were within 10% of the target concentration. In addition to dose formulation analysis prior to dosing, samples collected after dosing (animal room samples) were analysed periodically.

Duration of treatment / exposure:

104-105 wk

Frequency of treatment:

Five exposures per week

Post exposure period:

No

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

50 mg/kg bw/day (nominal)

Remarks:

Corresponding to 85 mg/mL in ethanol

Dose / conc.:

100 mg/kg bw/day (nominal)

Remarks:

Corresponding to 170 mg/mL in ethanol

No. of animals per sex per dose:

50

Control animals:

yes, concurrent vehicle

Details on study design:

Dose selection rationale: Dose selection was based primarily on the increased incidences of a spectrum of skin lesions at the site of application. Doses of 200 and 400 mg/kg bw caused high incidences of chronic inflammation and ulceration in males and females. Final mean body weights and body weight gains of male rats treated with 200 or 400 mg/kg bw were also less than those of the vehicle controls. Therefore, 200 and 400 mg/kg bw were considered inappropriate for the study. There was a very obvious reduction in toxic response of the skin at 100 mg/kg bw, with chronic inflammation and ulceration being absent in females and present in only one male; thus, 100 mg/kg bw was selected as the high dose for the 2-yr rat study. The responses observed at 25 and 50 mg/kg bw were very similar and consisted of only minimal hyperplasia; therefore, 50 mg/kg bw was selected as the low dose for the study.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: At study initiation, at 4-wk intervals during the study, and at necropsy

DERMAL IRRITATION (if dermal study): Yes

BODY WEIGHT: Yes
- Time schedule for examinations: Animals were weighed initially at the study initiation, weekly during weeks 1-13, at 4-wk intervals thereafter, and at the end of the study.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: No

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

Method of Sacrifice: Carbon dioxide asphyxiation

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes, Complete histopathology was performed on all animals. In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone and marrow, brain, clitoral gland, esophagus, heart, large intestine (cecum, colon, rectum), small intestine (duodenum, jejunum, ileum), kidney, liver, lung, lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin, spleen, stomach (forestomach and glandular), testis (and epididymis and seminal vesicle), thymus, thyroid gland, trachea, urinary bladder, and uterus.

Statistics:

Survival Analyses: The probability of survival was estimated by the product-limit procedure of Kaplan and Meier (1958). Possible dose-related effects on survival were analysed by Cox’s (1972) method for testing two groups for equality and Tarone’s (1975) life table test to identify dose-related trends. All reported P values for the survival analyses were two sided.

Analysis of Neoplasm and Nonneoplastic Lesion Incidences: The Poly-k test (Bailer and Portier, 1988; Portier and Bailer, 1989; Piegorsch and Bailer, 1997) was used to assess neoplasm and nonneoplastic lesion prevalence. Tests of significance included pairwise comparisons of each dosed group with controls and a test for an overall dose-related trend. Continuity-corrected tests were used in the analysis of lesion incidence, and reported P values are one sided.

Clinical signs:

no effects observed

Description (incidence and severity):

No significant difference clinical findings was observed between the dosed groups and the vehicle control groups.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

No significant difference in survival was observed between the dosed groups and the vehicle control groups.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No significant difference was observed in the mean body weights between the dosed groups and the vehicle control groups.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Changes of minimal to moderate severity occurred in the skin at the site of application in treated male and female rats. The major alterations from normal skin were thickening of the epidermis (epidermal hyperplasia) and sebaceous gland hyperplasia (which usually occurred along with epidermal hyperplasia). Incidences of chronic inflammation, hyperkeratosis, and parakeratosis in all dosed groups were significantly greater than those in the vehicle controls, as were the incidences of ulceration in 100 mg/kg bw males and females. The nonneoplastic skin lesions at the site of application were considered to be indicative of local irritation with no neoplastic or preneoplastic changes.

Histopathological findings: neoplastic:

no effects observed

Description (incidence and severity):

No significant differences was reported between the vehicle control groups and dosed groups in the incidences of neoplasms.

Other effects:

not examined

Details on results:

OTHER FINDINGS: The incidence of forestomach ulcer was significantly lower in males that received 100 mg/kg bw/d than in the vehicle controls. The incidences of inflammation of the nasal mucosa were significantly lower in dosed males than in the vehicle controls. The incidence of chronic inflammation of the liver was significantly lower in females administered 100 mg/kg bw than in the vehicle controls.

Relevance of carcinogenic effects / potential:

Yes

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 100 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: Under the test conditions, no evidence of carcinogenic activity for the test substance was reported.

For detailed resuls tables kindly refer to the attached background materials section of the IUCLID.

Conclusions:

Under the study conditions, no evidence of carcinogenic activity for the test substance was observed at any of the dose levels tested.

Executive summary:

A study was conducted to evaluate the long-term repeated dose dermal carcinogenicity in Fischer 344 rats of the test substance, C12 DEA, in compliance with GLP. Groups of 50 male and 50 female rats were exposed to dermal doses equivalent to 0, 50 or 100 mg/kg/day, 5 d/week, during 104-105 weeks. The animals were observed twice daily. Body weights and clinical findings were recorded periodically. Necropsy and complete histopathology was performed on all animals at test end. There were no significant differences between vehicle control and dosed males or females in survival or mean body weights. There were no chemical-related differences in neoplasm incidences. Dose-related increases occurred in the incidences of non-neoplastic lesions of the skin at the site of application, including epidermal and sebaceous gland hyperplasia, hyperkeratosis, chronic inflammation, parakeratosis, and ulcer. Under the study conditions, no evidence of carcinogenic activity for the test substance was observed at any of the dose levels tested (NTP, 1999).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Justification for classification or non-classification

The available data suggests that C12 DEA is not carcinogenic to humans. Although rodent carcinogenicity studies conducted on C12 DEA provided some evidence of carcinogenicity in mice, it was concluded that this was due to the presence of a contaminant - free diethanolamine (DEA, EC no. 203 -868 -0, CAS no. 111 -42 -2) – in the test substance. DEA has been shown to be a non-genotoxic carcinogen in mice. However, the proposed mode of action indicates a rodent-specific phenomenon involving choline depletion which is not relevant to man. This evaluation is supported by a recent decision by a scientific board of the National Toxicology Program (NTP) after a public hearing at which it was decided that DEA should not be listed as a carcinogen under the RoC (Report on Carcinogens) process. DEA has also recently been reviewed in the EU under the REACH regulation and no classification for carcinogenicity has been proposed ( https://echa.europa.eu/registration-dossier/-/registered-dossier/15770/2/1/?documentUUID=
b015c4bf-61f0-4b7b-b858-cfe6f686f088). Therefore, based on the overall weight of evidence C12 DEA does not require classification for carcinogenicity according to CLP (EC 1272/2008) criteria.

Additional information

A study was conducted to evaluate the long-term repeated dose dermal carcinogenicity in B6C3F1 mice of the test substance, C12 DEA, in compliance with GLP. Groups of 50 male and 50 female mice were exposed to dermal doses equivalent to 0, 100 or 200 mg/kg/day, 5 d/week, for 105-106 weeks. The animals were observed twice daily. Body weights and clinical findings were recorded periodically. Necropsy and complete histopathology was performed on all animals at test end. Mean body weights of females in 200 mg/kgbw/d dose group were lower than those of the vehicle controls beginning at week 33. The incidences of hepatocellular adenoma or carcinoma (combined) were significantly increased in treated females compared to the vehicle controls, as was the incidence of hepatocellular adenoma in the100 mg/kg bw/day female group. There were dose-related increases in the incidences of non-neoplastic lesions of the skin at the site of application, including epidermal and sebaceous gland hyperplasia, hyperkeratosis, chronic inflammation, and parakeratosis. Treated males had greater incidences of thyroid gland follicular cell focal hyperplasia than did the vehicle controls; the incidence in the 200 mg/kg bw/d group was significantly greater than that in the vehicle control group. Under the study conditions, no evidence of carcinogenic activity was reported in male mice. Some evidence of carcinogenic activity in female mice based on increased incidence of hepatocellular neoplasms was associated with free diethanolamine (DEA), which was present as a contaminant of the test substance (NTP, 1999). However, recent evidence suggests that DEA should not be classified as a carcinogen, as the hepatic tumours seen in mice and the proposed mode of non-genotoxic mechanism are not relevant to humans/primates.

A study was conducted to evaluate the long-term repeated dose dermal carcinogenicity in Fischer 344 rats of the test substance, C12 DEA, in compliance with GLP. Groups of 50 male and 50 female rats were exposed to dermal doses equivalent to 0, 50 or 100 mg/kg/day, 5 d/week, during 104-105 weeks. The animals were observed twice daily. Body weights and clinical findings were recorded periodically. Necropsy and complete histopathology was performed on all animals at test end. There were no significant differences between vehicle control and dosed males or females in survival or mean body weights. There were no chemical-related differences in neoplasm incidences. Dose-related increases occurred in the incidences of non-neoplastic lesions of the skin at the site of application, including epidermal and sebaceous gland hyperplasia, hyperkeratosis, chronic inflammation, parakeratosis, and ulcer. Under the study conditions, no evidence of carcinogenic activity for the test substance was observed at any of the dose levels tested (NTP, 1999).