2,2',2''-nitrilotriethanol citrate

Endpoint summary

Description of key information

Results for repeated dose toxicity were based on the LD50 of TEA (CAS no. 102-71-6), one of the two dissociation products of the substance (CAS no. 29340-81-6).

In a sub-chronic oral toxicity study, a NOAEL of 1000 mg/kg bw/day was established for TEA, the highest dose tested.

In a sub-acute inhalation toxicity study with rats, a NOAEC for systemic effects of 0.5 mg/L was established for TEA, the highest dose tested. 0.02 mg/L (the lowest dose tested) was considered to be the NOAEC for local effects in females. Since slight local effects were observed in males, this concentration was determined to be the LOAEC for local effects in males.

In a sub-chronic dermal toxicity study, NOAEL's of 125 and 250 mg/kg bw/day were established for local effects for males and females. Systemic NOAEL's of 125 and 500 mg/kg bw/day were determined for males and females, respectively, based on kidney effects. Similar effects were observed in a sub-chronic dermal study in mice, performed according to the same protocol.

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:

key study

Justification for type of information:

See read-across record in section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 other: mg/kg bw

Sex:

male/female

Basis for effect level:

other: no significant effects at highest dose tested

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Critical effects observed:

no

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Reliable oral repeated dose toxicity study (Klimisch 2) available.

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See read-across record in section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Dose descriptor:

NOAEC

Remarks:

systemic effects

Effect level:

0.5 mg/L air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects at highest concentration tested

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Key result

Dose descriptor:

NOAEC

Remarks:

local effects

Effect level:

<= 0.02 mg/L air

Based on:

test mat.

Sex:

male

Basis for effect level:

other: irritation of the upper respiratory tract, minimal to moderate focal inflammatory change in the submucosa of the larynx

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

NOAEC

Remarks:

local effects

Effect level:

0.02 mg/L air

Based on:

test mat.

Sex:

female

Basis for effect level:

other: irritation of the upper respiratory tract

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

BMCL05

Remarks:

Local effects

Effect level:

14.1 mg/m³ air

Based on:

test mat.

Sex:

female

Basis for effect level:

other: irritation of the upper respiratory tract

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

BMCL05

Remarks:

Local effects

Effect level:

14.8 mg/m³ air

Based on:

test mat.

Sex:

male

Basis for effect level:

other: irritation of the upper respiratory tract, minimal to moderate focal inflammatory change in the submucosa of the larynx

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

NOAEC

Effect level:

0.42 mg/L air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no substance related findings

Remarks on result:

other: Result read-across source CAS No. 102-71-6 (supporting)

Key result

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

500 mg/m³

Study duration:

subacute

Species:

rat

Quality of whole database:

Reliable inhalation repeated dose toxicity study (Klimisch 2) available.

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See read-across record in section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Dose descriptor:

NOAEC

Remarks:

systemic effects

Effect level:

0.5 mg/L air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects at highest concentration tested

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Key result

Dose descriptor:

NOAEC

Remarks:

local effects

Effect level:

<= 0.02 mg/L air

Based on:

test mat.

Sex:

male

Basis for effect level:

other: irritation of the upper respiratory tract, minimal to moderate focal inflammatory change in the submucosa of the larynx

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

NOAEC

Remarks:

local effects

Effect level:

0.02 mg/L air

Based on:

test mat.

Sex:

female

Basis for effect level:

other: irritation of the upper respiratory tract

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

BMCL05

Remarks:

Local effects

Effect level:

14.1 mg/m³ air

Based on:

test mat.

Sex:

female

Basis for effect level:

other: irritation of the upper respiratory tract

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

BMCL05

Remarks:

Local effects

Effect level:

14.8 mg/m³ air

Based on:

test mat.

Sex:

male

Basis for effect level:

other: irritation of the upper respiratory tract, minimal to moderate focal inflammatory change in the submucosa of the larynx

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Dose descriptor:

NOAEC

Effect level:

0.42 mg/L air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no substance related findings

Remarks on result:

other: Result read-across source CAS No. 102-71-6 (supporting)

Key result

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LOAEC

20 mg/m³

Study duration:

subacute

Species:

rat

Quality of whole database:

Reliable inhalation repeated dose toxicity study (Klimisch 2) available.

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See read-across record in section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Dose descriptor:

NOAEL

Remarks:

systemic effects

Effect level:

125 mg/kg bw/day

Based on:

test mat.

Sex:

male

Basis for effect level:

other: increased relative kidney weight

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Remarks:

rat

Dose descriptor:

NOAEL

Remarks:

systemic effects

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

other: increased absolute and relative kidney weight

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Remarks:

rat

Dose descriptor:

NOAEL

Remarks:

local effects

Effect level:

125 mg/kg bw/day

Based on:

test mat.

Sex:

male

Basis for effect level:

other: chronic-active inflammation and acanthosis at the site of application

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Remarks:

rat

Dose descriptor:

NOAEL

Remarks:

local effects

Effect level:

250

Based on:

test mat.

Sex:

female

Basis for effect level:

other: chronic-active inflammation and acanthosis at the site of application

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Remarks:

rat

Dose descriptor:

NOAEL

Remarks:

systemic effects

Effect level:

250 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

organ weights and organ / body weight ratios

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Remarks:

mouse

Dose descriptor:

NOAEL

Remarks:

systemic effects

Effect level:

1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male

Basis for effect level:

organ weights and organ / body weight ratios

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Remarks:

mouse

Dose descriptor:

LOAEL

Remarks:

local effects

Effect level:

250 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

histopathology: non-neoplastic

Remarks on result:

other: Result read-across source CAS No. 102-71-6

Remarks:

mouse

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

250 mg/kg bw/day

System:

integumentary

Organ:

skin

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

125 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Two reliable dermal repeated dose toxicity studies (Klimisch 2) available.

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen Laboratories, Gilroy, CA
- Age at study initiation: 39 to 42 days
- Weight at study initiation: 59.2 - 85.4 g (males), 57.0 - 79.3 g (females)
- Fasting period before study: No
- Housing: Individual in polycarbonate cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 11 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.5 - 24
- Humidity (%): 35 - 65
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Type of coverage:

not specified

Vehicle:

acetone

Details on exposure:

TEST SITE
- Area of exposure: an area extending from the animal's mid-back to dorsal interscapular region
- Time intervals for shavings or clipplings: at least 24 hours prior to initial dose, and once weekly thereafter

REMOVAL OF TEST SUBSTANCE
No data

TEST MATERIAL
- Amounts applied: 2.0, 1.0, 0.5, 0.25, 0.125 and 0 g/kg bw
- Concentration: 1120, 560, 280, 140, 70 and 0 mg/mL
- Constant volume or concentration used: yes

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

90 days

Frequency of treatment:

5 days per week

Dose / conc.:

125 mg/kg bw/day (nominal)

Remarks:

Equivalent to 70 mg/mL

Dose / conc.:

250 mg/kg bw/day (nominal)

Remarks:

Equivalent to 140 mg/mL

Dose / conc.:

500 mg/kg bw/day (nominal)

Remarks:

Equivalent to 280 mg/mL

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Remarks:

Equivalent to 560 mg/mL

Dose / conc.:

2 000 mg/kg bw/day (nominal)

Remarks:

Equivalent to 1120 mg/mL

No. of animals per sex per dose:

20 animals per dose:
- 10 special study animals (designated for periodic urinalysis, haematology, and clinical chemistry determinations)
- 10 base study animals (subject to the collection of clinical observations data, sperm morphology and vaginal cytology evaluations, necropsy with gross examination and tissue collection, and histopathologic examination).

Control animals:

yes, concurrent vehicle

Details on study design:

Post-exposure period: no

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS
- Time schedule: Weekly

DERMAL IRRITATION
- Time schedule for examinations: Daily

BODY WEIGHT
- Time schedule for examinations: Weekly

HAEMATOLOGY
- Time schedule for collection of blood: Week 11
- Parameters examined were erythrocyte count (RBC), haemoglobin (HgB), haematocrit (HCT), leukocyte count (WBC), platelet count, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), leukocyte differential count, reticulocyte count, erythrocyte and platelet morphology.

CLINICAL CHEMISTRY
- Time schedule for collection of blood: Week 11
- Parameters examined were sorbitol dehydrogenase (SDH), glutamic-pyruvic transaminase activity (GPT), glutamic-oxaloacetic transaminase activity (GOT), urea nitrogen (BUN), creatinine, total protein, albumin, glucose.

URINALYSIS
- Time schedule for collection of urine: week 1, week 3, week 7 and week 12
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters examined were specific gravity, glucose, protein, microscopic examination of sediment.

CLINICAL CHEMISTRY
- Time schedule for collection of blood: Week 11
- Parameters examined were sorbitol dehydrogenase (SDH), glutamic-pyruvic transaminase activity (GPT), glutamic-oxaloacetic transaminase activity (GOT), urea nitrogen (BUN), creatinine, total protein, albumin, glucose.

URINALYSIS
- Time schedule for collection of urine: week 1, week 3, week 7 and week 12
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters examined were specific gravity, glucose, protein, microscopic examination of sediment.

Sacrifice and pathology:

- The following tissues were examined: gross lesions and tissue masses (and regional lymph nodes, if possible), blood smear (if required by the pathologist), mandibular and mesentric lymph nodes, salivary gland, sternebrae, femur, or vertebrae, including marrow, thyroids, heart, esophagus, stomach (to include forestomach and glandular stomach), uterus, brain (three sections, including frontal cortex and basal ganglia, parietal cortex and thalamus, and cerebellum and pons), thymus, trachea, parathyroids, small intestine (duodenum, jejunum, ileum), cecum, colon and rectum, liver, prostate, testis, epididymis, seminal vesicle, ovaries, lungs and mainstem bronchi, nasal cavity and nasal turbinates (3), preputial or clitoral glands (paired), pancreas, spleen, kidneys, adrenals, urinary bladder, pituitary, spinal cord and sciatic nerve (if neurology signs were present), eyes (if grossly abnormal), mammary gland (including surface skin), pharynx (if grossly abnormal), skin (lesions in dosed area, unaffected skin in dosed area, and undosed control skin).

- Complete histopathologic evaluation of all tissues listed was performed on all base study rats from the 2.0 and 0 g/kg dose groups. On the basis of those findings, the skin at the site of application (both males and females) and the kidney (females only) were selected as the target tissues. These tissues were examined in rats in successively lower dose groups to a no-effect level; in addition, any gross lesions detected at necropsy were examined microscopically.

Other examinations:

Sperm morphology and vaginal cytology were evaluated in the control and the three highest dose groups.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

The only clinical abnormalities associated with treatment with the test substance occurred at the site of dermal dose application. Other abnormalities were determined not to be compound induced.

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

Males:
- Discoloration of the skin was seen in males from all dose groups (including control); it was present in 6 males in the 0 g/kg dose group, and in all 10 base study animals in each of the dosed groups.
- Irritation at the site of application was seen in the three highest dosed groups (0.5, 1.0, and 2.0 g/kg), with incidence increasing and time to onset decreasing with increasing dose level.
- Scaliness was observed only at the 1.0 and 2.0 g/kg levels; this was observed in 1 rat in the 1.0 g/kg group (first seen on Day 13), and in 5 rats in the 2.0 g/kg group (first seen on Day 6).
- Crustiness at the site of application was recorded for 10 rats in the 2.0 g/kg dose group; two males from this group were also observed to have ulceration at the application site.
Females:
- Irritation was observed at the 1.0 (7 rats) and 2.0 (10 rats) g/kg dose levels.
- Scaliness was also seen in female rats from the 1.0 and 2.0 g/kg groups (4 animals dosed at the 1.0 g/kg level, and 5 animals dosed at the 2.0 g/kg level).
- Crustiness was present in 3 female rats dosed at 2.0 g/kg.

Mortality:

no mortality observed

Description (incidence):

All animals in all dose groups survived until scheduled termination.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The 2.0 g/kg male dose group exhibited a pronounced depression in body weight gain; the differential weight gain, relative to control, for this group was -32.8 percent, whereas those for the other male dosed groups ranged from -4.8 to +8.4 percent. The mean weight gains for all female dosed groups were depressed when compared with that of the female control group; the differential weight gains (relative to control group weight gain) for the 0.125, 0.25, 0.5, 1.0, and 2.0 g/kg female dose groups were -13.1, -10.6, -6.0, -21.4, and -35.9 percent, respectively.

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:

effects observed, treatment-related

Description (incidence and severity):

Haematology was performed on blood obtained from special study rats on study Day 80.
- Male rats dosed at 2.0 g/kg exhibited a significantly increased leukocyte count and decreased mean corpuscular volume.
- Significantly decreased mean corpuscular volume was also exhibited by the 2.0 g/kg female dose group; the haematocrit of this group was depressed as well.
- Male rats in the 2.0 g/kg dose group exhibited significant increases in both relative and absolute number of segmented neutrophils and eosinophils, and a significant reduction in the relative number of lymphocytes.
- Female rats treated at the same dosage level (2.0 g/kg) also exhibited a significant increase in relative and absolute numbers of segmented neutrophils, as well as a decrease in relative lymphocyte count.
These haematological changes in high dose rats of both sexes can be attributed to an inflammatory response resulting from dermal irritation. The mean values for all other dosed groups of both sexes were statistically similar to control.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Males:
- The 2.0 and 0.25 g/kg male dose groups exhibited elevated SGOT levels
- The mean SGPT level of the 2.0 g/kg male dose group was also significantly higher than control.
No other statistically significant changes were seen when mean data from the male dosed groups were compared with that of control.

Females:
- The 2.0 g/kg female dose group exhibited elevated serum urea nitrogen, albumin, SGOT, and SGPT.
The only other significant change in the female group mean data was a decrease in serum sorbitol dehydrogenase in rats dosed at 0.5 and 1.0 g/kg.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Urine, collected from special study group rats on Days 3, 16, 44, and 86, was analysed.
Males:
- At study Day 3, mean values for all male dosed groups were statistically similar to those of the male control group.
- At study Day 16, the only values statistically different from control were urine protein at the 1.0 g/kg level, and the number of leukocytes at the 0.25 g/kg level.
- By study Day 44, there was a significant reduction in urine protein levels in males dosed at 0.5, 1.0, and 2.0 g/kg; in addition, the specific gravity of urine collected from the 2.0 g/kg male dose group was significantly increased over control.
- At the final urinalysis (Day 86), the specific gravity of urine from rats in the 2.0 g/kg dose group was again significantly elevated, and the urine protein levels for the 0.5, 1.0, and 2.0 g/kg male dose groups were significantly lower than control. The only other parameter statistically different from control was increased urine volume in males dosed at 0.5 g/kg.

Females:
- At study Day 3, there was decreased urine protein concentration at the 0.25 g/kg level and above; the number of crystals found in the urine of rats in the 2.0 g/kg dose group was also significantly greater than control.
- On Day 16, increased number of crystals was also present, in females dosed at 1.0 and 2.0 g/kg.
- Beginning on Day 16, and continuing through Days 44 and 86, the specific gravity of urine from female rats from the two highest dose groups (1.0 and 2.0 g/kg) was significantly greater than that of control females.
- At Day 44, the only other statistically significant changes observed were increased urine protein concentration in females dosed at 0.5 g/kg, and increased number of crystals in females dosed at 2.0 g/kg.
- At Day 86, in addition to the increased urine specific gravity in the two highest dose groups, the 2.0 g/kg females exhibited an increase in urine glucose concentration.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Final body weight:
- The mean final body weights for both male and females dosed at 2.0 g/kg body weight were significantly decreased (p <0.01), compared with those of their respective control groups.

Organ weights:
- The mean brain to body weight values for the 2.0 g/kg male and female dose groups were significantly increased relative to control. In the absence of statistical changes in the absolute brain weight for these groups, this increase in relative weight appears to be the result of depressed final body weights in rats dosed at 2.0 g/kg.
- Statistically significant increases in mean right kidney absolute weights and weights relative to brain weight occurred in both males and females dosed at 1.0 and 2.0 g/kg. The right kidney to body weight ratios of the 0.25, 0.5, 1.0, and 2.0 g/kg male dose groups and the 1.0 and 2.0 g/kg female dose groups were also significantly increased over that of control.
- The mean spleen absolute weight and spleen weight relative to brain weight of the 2.0 g/kg female dose group were significantly decreased, relative to control values. There was a significant increase in the mean spleen to body weight ratio in male rats dosed at 1.0 and 2.0 g/kg.
- Thymus absolute weight and weight relative to brain weight were increased in males dosed at 2.0 g/kg body weight.
- Mean liver to body weight ratios for the 0.5 and 1.0 g/kg male dose groups were significantly elevated over that of control. No statistically significant changes were observed in mean liver weight values for the female dose groups.
- The mean lung absolute weight and lung to brain weight ratio of the 2.0 g/kg male dose group were significantly decreased, relative to control. The mean lung to brain weight of the 0.5 g/kg male dose group was also significantly decreased. The only statistically significant change in mean lung weight values for female rats was increased lung to brain weight ratio at the 0.125 g/kg level.
- No statistically significant changes were seen in mean heart weight data for male and female rats.
- For both testes, there was a significant increase in weight relative to body weight in the 2.0 g/kg male dose group; this was a result of decreased body weight at necropsy.
- No statistical changes were observed for mean left epididymis weight values. The 2.0 g/kg male dose group exhibited decreased right epididymis absolute weight, and increased weight relative to body weight. Right epididymis to body and to brain weight ratios were increased in males dosed at 0.25 g/kg.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Gross lesions were common on the skin of high dose rats. The compound-related lesion seen at the application site was dermal crust. Yellow skin was seen in the lumbar region of treated and control animals. This lesion had no corresponding microscopic lesion and is attributed to application of the vehicle (acetone). Other gross lesions were considered incidental, spontaneous lesions.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

- The compound-related skin lesions were chronic-active inflammation and acanthosis, and were seen in 2.0, 1.0, 0.5, and 0.25 g/kg male rats and in 2.0, 1.0, and 0.5 g/kg female rats.
- The chronic-active inflammation contained epidermal and dermal components.
- The epidermal component was characterized by acanthotic, hyperkeratotic, focally parakeratotic epidermis that occasionally contained rete pegs; these changes were graded separately as acanthosis. Severely affected epidermis contained focal haemorrhage, fibrin and/or mineral deposits, bacterial colonies, serum pockets, pustules, erosions and/or ulcers.
- The dermal component in severely affected rats was characterized bydermal fibrosis, neocapillarization, minimally distorted adnexal organs, and variably severe mixed inflammatory infiltrates consisting of histiocytes, lymphocytes, neutrophils and eosinophils.
- Although only the most severe grades of chronic-active inflammation contained all of the previously listed epidermal and dermal features, the lesion was regarded as a continuum, and, therefore, the morphology "chronic-active inflammation" was used in all dose groups.
- Less severe lesions of chronic-active inflammation had reduced acanthosis, and lacked one or more of the following components: epidermal haemorrhage, fibrin and/or mineral deposits, bacterial colonies, serum pockets, pustules, erosions and/or ulcers.
- Additionally, less severe lesions contained fewer of the dermal features of the most severe lesion.
- In minimal inflammatory lesions the epidermal component was predominant.
- Where only the term acanthosis was used, the least severe lesion contained 2-3 layers of epidermal cells above the basilar layer.
- Occasionally, there was minimal to mild dermal fibrosis associated with the acanthosis.
- In males and females there was a dose dependent reduction in severity and incidence of skin lesions from high to no-effect dose.
- Non-compound related microscopic lesions were seen in the kidney, liver, lung, prostate, ovary, preputial gland, clitoral gland, eye, Zymbal's gland, nose/nasal cavity; and mediastinal lymph node.

Histopathological findings: neoplastic:

no effects observed

Details on results:

The compound-induced skin lesions in males and females were chronic-active inflammation and acanthosis. The incidence, severity, and morphology of the lesions were similar between sexes. In males, however, the compound effect extended to one dose lower than in females. Although there was increased incidence of nephropathy from low to high dose in female rats, the severity of this lesion did not vary between dose groups, and, therefore, it was regarded as incidental. Other microscopic lesions were regarded as incidental and spontaneous or associated with retrobulbar bleeding.

Dose descriptor:

NOAEL

Remarks:

local effects

Effect level:

125 mg/kg bw/day

Sex:

male

Basis for effect level:

other: chronic-active inflammation and acanthosis at the site of application

Dose descriptor:

NOAEL

Remarks:

local effects

Effect level:

250 mg/kg bw/day

Sex:

female

Basis for effect level:

other: chronic-active inflammation and acanthosis at the site of application

Dose descriptor:

NOAEL

Remarks:

systemic effects

Effect level:

125 mg/kg bw/day

Sex:

male

Basis for effect level:

other: increased relative kidney weight

Dose descriptor:

NOAEL

Remarks:

systemic effects

Effect level:

500 mg/kg bw/day

Sex:

female

Basis for effect level:

other: increased absolute and relative kidney weight

Critical effects observed:

no

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Study duration:

subchronic

Species:

rat

Quality of whole database:

Two reliable dermal repeated dose toxicity studies (Klimisch 2) available.

Additional information

No substance-specific data on repeated dose toxicity of the substance (CAS no. 29340-81-6) are available. However, according to Article 13 of legislation EC1907/2006, in case no appropriate animal studies are available for assessment, information should be generated whenever possible by means other than vertebrate animal tests, i. e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across. CAS no. 29340-81-6 is an acidic salt of triethanolamine (TEA, CAS no. 102-71-6) and citric acid and is expected to dissociate into the respective triethanolammonium cation and dihydrogen citrate anion (which may subsequently undergo (partial) dissociation to monohydrogen citrate and citrate anions) upon uptake by the body. Therefore it is considered to be acceptable to derive lacking information on toxicological properties of CAS no. 29340-81-6 by read-across from its starting materials.

 

Citric acid is an important intermediate of the Krebs cycle (also known as citric acid cycle), and therefore occurs naturally as a metabolite in virtually all living organisms. It is also used as a natural food preservative and a food additive. The average daily intake (ADI) is not limited according to the evaluation of Joint FAO/WHO Expert Committee on Food Additives (1973), which concluded that the substance is non-hazardous to men. No repeated dose toxicity studies on citric acid are available. However, taken into account its widespread use for many decades, also in food products, and the lack of reports on human repeated dose toxicity associated with its use, it is highly unlikely that citric acid may possess a risk after repeated exposure. Therefore the toxicological behaviour of CAS no. 29340-81-6 is expected to be governed primarily by the toxicity of TEA.

 

Oral

In a sub-chronic oral toxicity study, performed similar to OECD Guideline 408, twenty Cox CD rats/sex/dose were exposed to 0, 250, 500 or 1000 mg/kg bw/day TEA in the diet for 91 days. One male from the mid-dose group and one female from the low-dose group displayed symptoms of inner ear infection. The only adverse significant differences noted were in body weight gain and feed efficiency in the female rats of the mid-dose group. There were no significant differences notes in organ to body weight ratios. No lesions were found which followed a pattern of agent-induced toxicity. Tissue alterations observed were mild and were not considered significant. The only abnormality observed in haematology was a slightly elevated white bloodcell count in one animal. This change was not considered significant. All other values are within normal limits and there were no significant differences between treatment groups. Therefore, the NOAEL was established to be 1000 mg/kg bw/day, the highest dose tested (EPA, 1989).

 

Inhalation

In a 5 -day range finding test, following GLP, five Wistar rats/sex/dose were whole-body exposed to 0.10, 0.20, or 0.42 mg/L TEA as aerosol. No mortality and no toxicological significant substance related clinical signs and findings different from normal over the study was observed. There was no substance related significant influence neither on body weight nor on body weight gain. In addition, no toxicological relevant effects on clinical chemistry, haematology, neurobehavioural signs and functions, and gross pathology was observed (BASF, 1991).

 

In a repeated dose inhalation toxicity test, performed according to OECD Guideline 412 and following GLP, ten Wistar rats/sex/dose were exposed head/nose only to 0, 0.02, 0.1 or 0.5 mg/L TEA as aerosol for 6 hours/day, 5 days/week. No mortality was observed. No statistically significant differences between groups were observed in body weight, haematology and clinical chemistry. Functional observational battery did not reveal any substance-induced neurofunctional impairment in the treated groups when compared to control. Local effects were characterized histopathologically by focal inflammatory changes in the submucosa of the larynx, with a concentration-dependent tendency in incidence and severity. No such effects were observed in females of the low dose, whereas minimal to slight effects were seen in males at this dose. Therefore, 0.02 mg/L was considered to be the NOAEC for local effects in females and the LOAEC for males. Since no systemic effects were observed, the systemic NOAEC was determined to be 0.5 mg/L, the highest dose tested (BASF, 1993).

 

Dermal (rats)

In a sub-chronic dermal toxicity study, performed similar to OECD Guideline 411, twenty Fischer 344 rats/sex/dose were exposed to 0, 125, 250, 500, 1000 or 2000 mg/kg bw/day TEA on the skin, 5 days/week for 13 weeks. Ten additional animals were used for periodic urinalysis, haematology, and clinical chemistry determinations and another ten animals were used for collection of clinical observation data, sperm morphology and vaginal cytology evaluations, necropsy with gross examination and tissue collection, and histopathological examination. No mortality was observed. The only clinical abnormalities associated with treatment occurred at the site of dermal dose application. Depression in body weight was observed. Hematologic changes observed in the high dose group were consistent with the presence of skin inflammation. Clinical chemistry findings included elevated SGOT levels in the 2000 and 250 mg/kg bw male dose groups, and significantly higher SGPT level of the 2000 mg/kg bw male dose group. The 2000 mg/kg bw female dose group exhibited elevated serum urea nitrogen, albumin, SGOT, and SGPT. The only other significant change in the female group mean data was a decrease in serum sorbitol dehydrogenase in rats dosed at 500 and 1000 mg/kg bw. Urinalysis revealed that the specific gravity of urine from rats in the 2000 mg/kg bw dose group was significantly elevated, and the urine protein levels for the 500, 1000, and 2000 mg/kg bw male dose groups were significantly lower than control. In females, the specific gravity from the two highest dose groups was significantly greater than that of control females and urine glucose concentration was increased in the highest dose group. Gross lesions were common on the skin of high dose rats. Other gross lesions were considered incidental, spontaneous lesions. In the high dose groups, changes in several organ weights was observed. Kidney and liver weights were affected in lower dose groups. The only histopathological effect observed were lesions at the site of application which ranged from no discernible change, through minimal to mild epidermal thickening (acanthosis), to chronic active inflammation, erosion, and ulceration. The dermis was also thickened with inflammation and fibrosis at the higher doses. NOAELs for local effects were determined to be 125 and 250 mg/kg bw/day for males and females, respectively. The NOAELs for systemic effects were established to be 125 and 500 mg/kg bw/day for males and females, respectively, based on effect on kidney weights (Battelle, 1987).

 

Dermal (mice)

In a sub-chronic dermal toxicity, performed identical to the study in rats as described above, mice were exposed to 0, 250, 500, 1000, 2000 or 4000 mg/kg bw/day TEA on the skin. No mortality was observed. Significant clinical abnormalities were restricted to the site of dermal dose application in both sexes of the high dose group. Treatment with TEA had no apparent effect on body weight gain. Gross lesions were common on the skin of high dose mice. Regarding haematology, mean data for all TEA-dosed male groups were statistically similar to controls. In females dosed at 4000 mg/kg bw, there were significant increases in the number of leukocytes and the mean corpuscular haemoglobin concentration. There was also a slight, but statistically significant, decrease in the mean corpuscular volume of the 2000 mg/kg bw dose group. All other mean values for TEA-dosed female mice were statistically similar to control. In males, there was a dose-related, statistically significant decrease in serum sorbitol dehydrogenase that occurred in all dosed groups, but the mean values for all other parameters measured were statistically similar to control. In females, there was also a significant decrease in serum sorbitol dehydrogenase at all treatment levels. Additionally, there was an increase in both serum total protein and albumin in the 2000 mg/kg bw dose group, and a significant decrease in alanine aminotransferase in the 1000 mg/kg bw dose group. No effect on urinalysis was observed at the end of the treatment period. The absolute kidney and liver weights of males and females administered 4000 mg/kg bw were greater than those of controls. In addition, relative kidney weights of males administered 1000 mg/kg bw or greater and females in all dosed groups were also greater than those of the controls. Microscopic examination revealed effects to the skin of dosed mice which indicated acanthosis and inflammation. Based on the available data, the NOAEL for local effects was determined to be ≤ 250 mg/kg bw/day and based on kidney effects. NOAELs for systemic effects were determined to be 1000 and ≤ 250 mg/kg bw/day for males and females, respectively (Battelle, 1987).

 

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint: 

Only study available. 

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint: 

Only sub-acute toxicity study available.

Justification for selection of repeated dose toxicity inhalation - local effects endpoint: 

Only sub-acute toxicity study available. 

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint: 

Of the two reliable dermal repeated dose toxicity studies, this study determined a NOAEL while in the other test higher concentrations were tested and only a LOAEL could be derived. 

 

Justification for selection of repeated dose toxicity dermal - local effects endpoint: 

Of the two reliable dermal repeated dose toxicity studies, this study determined a NOAEL while in the other test higher concentrations were tested and only a LOAEL could be derived.

Justification for classification or non-classification

Based on the results of the available studies, classification for repeated dose toxicity is not warranted in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation No. (EC) 1272/2008.