Tripropylamine

Endpoint summary

Description of key information

No reliable repeated dose toxicity studies are available for TnPA. Read-across from the closely related substances TEA and TnBA reveals that irritation and corrosion is the primary effect, and that dose levels producing systemic effects cannot be reached. For tri-n- propylamine a conservative German MAK value of 1 ppm is therefore proposed, in analogy to other alkylamines.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study; no data regarding GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

Principles of method if other than guideline:

No data on detailed clinical observation, sensory reactivity to stimuli, assessment of grip strength, and motor activity

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

-Age: 9 week old

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

no details given

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

no details given

Duration of treatment / exposure:

42 days; Females: 2 weeks prior to breeding, continuing through breeding (2 weeks), gestation (3 weeks), lactation (4 days), and until the day of necropsy (test day 40 or 54).

Frequency of treatment:

Once daily

Remarks:

Doses / Concentrations:
0, 8, 40, 200 mg/kg/day (in water)
Basis:

No. of animals per sex per dose:

13/sex/dose group

Control animals:

yes, concurrent vehicle

Details on study design:

Post-exposure period: None

Observations and examinations performed and frequency:

General condition was observed at  least once a day during breeding and at least twice a day before and after dosing over the administration period. Body weights for males were  determined on days 1, 7, 14, 21, 28, 35, 42 and on the day of necropsy.   Body weights were determined for all females on days 1, 7, 14.  Females  who took time before mating were weighed on days 35 and 42.  Females who copulated were weighed on pregnancy days 0, 7, 14 and 20.  Females who  delivered were weighed on nursing days 0, 4, and on the day of necropsy.   Females who copulated but did not deliver were weighed on the equivalent  of pregnancy day 25 (day of necropsy).  
Food consumption was measured on  days 1, 7, 13, 29, 35 and 41 for males, and on days 1, 7, and 13 for all  females.  Females with unconfirmed copulation were measured for food  consumption on days 29, 35 and 41.
Urinalysis was conducted on 5 rats/sex/dose level at week 6.
Hematology and clinical chemistry: Males prior to necropsy and on the  following day after day 42 administration; Females prior to necropsy:  females who delivered-following nursing day 4, females who mated but did  not deliver-equivalent of pregnancy day 25, and females who did not mate-  following day 54 of administration

Sacrifice and pathology:

-Hematology and clinical chemistry: Males prior to necropsy and on the  following day after day 42 administration; Females prior to necropsy:  females who delivered-following nursing day 4, females who mated but did  not deliver-equivalent of pregnancy day 25, and females who did not mate-  following day 54 of administration.

ORGANS EXAMINED AT NECROPSY (MACROSCOPIC AND MICROSCOPIC):
-Macroscopic: organ weights: brain, heart, thymus, liver, kidneys,  spleen, adrenals, testes and epididymides; pups were autopsied on day 4  and external and internal organs observed; with females, ovaries and  uteri were extracted, the pregnancy corpora lutea number of the ovary was  counted under the stereoscopic microscope, the implantation number of the  uterus was counted, and the implantation rate ((implantation  number/pregnancy corpora lutea number) x 100) was calculated.
-Microscopic: 5 animals/sex/control and high dose group- brain, pituitary  gland, spinal cord, digestive tract,, liver, kidneys, adrenal, spleen,  heart, thymus, thyroid gland, trachea, lung, bladder, mesenteric lymph  nodes, lower jaw lymph nodes, sciatic nerves, thigh bone marrow,  sperm and prostrate ventral lobes of all males and vagina, ovaries  and uteri of all females; also testes, epididymides, ovaries and stomachs  found to be abnormal during pathologic examinations were all examined  histopathologically 

Other examinations:

no data

Statistics:

Fisher's Exact Test- mating and conception rate,
Mann-Whitney U Test (2-tailed) and Fisher's Exact Test (1-tailed)- histopathological examinations,
Dunnett's Multiple Comparison Test (significance level=5%)- body weight, food consumption, hematology, clinical chemistry and organ weights

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

not specified

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Details on results:

-Mortality and time to death: 1 male given 200 mg/kg/day died on day 25,  1 male given 200 mg/kg/day died on day 42 and 1 female died on pregnancy  day 22 (administration day 38)
-Clinical signs prior to death (200 mg/kg/day): Day 25 male, showed  salivation, emaciation, abnormal breathing noise and dyspnea from  administration day 19, and vulval periphery fur soil and loose passage  were observed from the day before the death. Day 42 male, showed  salivation, emaciation, abnormal breathing noise, dyspnea, a drop in body  temperature, faded auricle, tottering and brown soil around the nose were  observed from administration day 10, although discontinuously. The female  was observed with salivation and abnormal breathing noise sporadically  from administration day 11.
-Clinical signs in surviving animals: 200 mg/kg/day: Males- salivation  10/13, abnormal breathing noise 3/13, and decreased contact response  1/13; Females-salivation 10/13, abnormal breathing noise 3/13, and  emaciation 1/13.    40 mg/kg/day: no abnormalities
-Body weights: Males- No significant differences in body weights at 200  mg/kg/day; however, body weight gains were decreased when compared to  controls.  There were no significant differences in body weight or body  weight gains in males administered   40 mg/kg/day.  Females- No  significant differences in body weight or body weight gains.
There was no effect of trimethylamine administration on body weights and food consumption of the females and on organ weights, urine examination and hematological examination results in the males and females.

Dose descriptor:

NOAEL

Effect level:

40 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: general toxic changes 

Dose descriptor:

NOAEL

Effect level:

200 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: reproductive/developmental toxic changes for both  males and females and for delivered pups

Critical effects observed:

not specified

Conclusions:

The no observed effect dose level (NOEL) for systemic toxicity of trimethylamine is considered to be 40 mg/kg bw/day in males in females. NOELs for reproductive and developmental toxicity are considered to be 200 mg/kg bw /day in males and females, and 200 mg/kg bw/day in pups, respectively (http://dra4.nihs.go.jp/mhlw_data/home/file/file75-50-3.html, 01.09.2011)

Executive summary:

Takashima et.al. performed in 2003 a subchronic repeated dose toxicity test according to OECD guideline 422. 13 male and female rats (Sprague-Dawley) each were exposed to a daily oral administration of trimethylamine by gavage. This resulted in the death of two males and 1 female administered 200 mg/kg/day. Abnormal breathing noise, salivation immediately after the administration, ulcers and inflammatory changes in the stomach and intestinal tracts, squamous hyperplasia and oedema in submucosa were observed in both males and females in the 200 mg/kg/day group. An inhibition tendency in body weight increase, decrease in food consumption, total protein concentration and albumin concentration were also observed in the males in the same group. There was no effect of trimethylamine administration on body weights and food consumption of the females and on organ weights, urine examination and hematological examination results in the males and females. Therefore it was inferred that the general toxicological NOAEL (No Observed Adverse Effect Level) is 40 mg/kg/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

40 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

good quality

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No GLP. Acceptable well documented publication which meets basic scientific principles.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 452 (Chronic Toxicity Studies)

Deviations:

yes

Principles of method if other than guideline:

In the present study only two dose levels were used in addition to the concurrent control group. The duration of the study is 28 weeks. Not all examinations are performed.

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:

Strain:Weanling caesarean-derived Fisher F344 [CDF (F-344)/Crl BR]
Rats were screened for serological evidence of Mycoplasma pulmonis infection prior to the initiation of exposures and all results were negative.
- Source: Charles River breeding Laboratories, Wilmington MA
- Age at study initiation: not reported
- Weight at study initiation: not reported
- Fasting period before study: no
- Housing: individually
- Diet (e.g. ad libitum): except during the exposure periods.
- Water (e.g. ad libitum): except during the exposure periods.
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Air changes (per hr): 12-15/hour
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

not specified

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Exposures were conducted in three 4.5 m³ stainless steel and glass inhalation chambers (Hinners et al., 1968) operated under dynamic flow conditions.

- Temperature, humidity in air chamber: 23 ± 3°C and 50 ± 10% RH, respectively.
- Air flow rate: 12-15 air changes per hr
- Treatment of exhaust air: A fresh batch of TEA was used in the generation reservoir each day.

TEST ATMOSPHERE
- Brief description of analytical method used: Wilks-Miran 1A Infrared Analyzer (Foxboro Analytical, Norwalk, CT) using the following instrument settings: wavelength 9 µm, pathlength 6.2 m, slit 1.0 mm. The instrument was calibrated by the closed loop calibration method. Adjustments were made to the generation system, as required, to maintain the exposure levels at the targeted concentrations.
- Samples taken from breathing zone: yes. TEA concentrations in the chamber were monitored 2-4 times per hour using a Wilks-Miran 1A Infrared Analyzer (Foxboro Analytical, Norwalk, CT)

VEHICLE (if applicable) no

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

2-4 times/hour with a Wilks-Miran Infrared Analyzer

Duration of treatment / exposure:

28 weeks

Frequency of treatment:

6 hours/day, 5 days/week

Remarks:

Doses / Concentrations:
0, 25 and 247 ppm  (0, 103 and 1020 mg/m³)
Basis:
nominal conc.

No. of animals per sex per dose:

50/sex/dose

Control animals:

yes

Details on study design:

- Dose selection rationale: Exposure concentrations were selected to provide comparisons to previous toxicity determinations conducted in this laboratory with diethylamine at 25 and 250 ppm (Lynch et al., 1986).
- Rationale for animal assignment (if not random): randomised

Positive control:

no

Observations and examinations performed and frequency:

Observations: Twice daily observations were made for changes in appearance or demeanor. Body weights were recorded on the day preceding the first day of exposure, at 2-week intervals throughout the study (at the end of an exposure day), and immediately prior to scheduled sacrifice.

Sacrifice and pathology:

10/sex/treatment sacrificed after ~30 and ~60 days of exposure, 20 after  ~ 125 days of exposure (10 in controls) 

GROSS PATHOLOGY: Yes
A complete necropsy was performed, and lungs, liver, kidneys, and heart were weighed.

HISTOPATHOLOGY: Yes
The following tissues were examined histologically: lungs (following infusion with 10% formalin), liver, kidneys, heart, spleen, tracheobronchial lymph nodes, adrenals, urinary bladder, testes, seminal vesicles, uterus, ovaries, trachea, eyes and nasal passages (processed and cut as described by Buckley et al. 1985).

Other examinations:

Clinical Chemistry-Hematoiogy:
The following clinical chemistry indices were measured at each scheduled sacrifice on a Gemsaec Centrifugal Analyzer (Electro-Nucleonics, Inc., Fairfield, NJ): alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine phosphokinase (CPK), blood urea nitrogen (BUN), creatinine (CRE) and sorbitol dehydrogenase (SDH). Hematology evaluations, conducted only at the terminal sacrifice, included hemoglobin, hematocrit, complete blood count and differential;

ECG were recorded at terminal sacrifice in 9-11 rats/sex/treatment

Statistics:

Multiple t-tests were used to compare initial body weights, while a multivariate analysis of variance was used to compare weight gains at each additional weighing period. Organ weights, organ-to-body weight ratios, hematology, clinical chemistry and electrocardiographic indices of the groups were compared by sex and length of exposure using the Kruskal-Wallis test (Hollander and Wolfe, 1973). Pathology incidence data were evaluated using a x² test. All comparisons between control and exposed animals were made at a statistical significant level of a = 0.05. Results were considered significant when p < 0.05.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

clinical signs

Mortality:

mortality observed, treatment-related

Description (incidence):

clinical signs

Body weight and weight changes:

no effects observed

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:

no effects observed

Description (incidence and severity):

no statistical difference

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

only sporadic changes

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

no statistical difference

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

no statistical significance

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

but unrelated to chemical exposure

Details on results:

CLINICAL SIGNS AND MORTALITY:
Rats of both sexes tolerated the exposure at 25 ppm without exhibiting overt signs of toxicity. At 247 ppm TEA the rats kept their eyes closed and noses buried in their fur during the entire exposure period.
All rats survived the exposures except for one female rat in the 25 ppm TEA group which was sacrificed due to malocclusion (week 6), two 250 ppm TEA female rats which died following an accidental injury (week 3), and one 250 ppm male rat which died during the exposure period (week 8). These deaths could not be attributed to TEA exposure.

BODY WEIGHT AND WEIGHT GAIN
Body weight was not statistically affected; however there was a slight dose-related reduction which occured in the TEA exposed male rats compared to the control

HAEMATOLOGY
Hematologic analyses revealed no statistical differences in male or female rats exposed to TEA for 28 weeks.

CLINICAL CHEMISTRY
Several clinical chemistry indices, i.e. SDH, ALT and creatinine, were elevated in one group of rats, or in only one sex of rats, at one of the scheduled interim sacrifices. These changes were not attributed to TEA exposure since they were sporadic in occurence and not concentration related.

ORGAN WEIGHTS
No consistent statistically significant differences in absolute or relative organ weights were seen in rats exposed to TEA and killed at any of the sceduled sacrifices. Lung weights and lung-to-body weight ratios were increased in all four groups of male and female rats exposed to TEA for 28 weeks, and absolute heart weights were increased in both groups of male rats exposed to TEA for the same period.

GROSS PATHOLOGY
There were no gross pathologic observations in rats which were considered to be related to treatment.

HISTOPATHOLOGY: NON-NEOPLASTIC
Chronic inflammation of the lungs was seen in all treated and control animals  exposed for 28 weeks. Liver lesions consisiting of minimal foci of necrosis were detected in males of all three groups exposed for 28 weeks. Minimal focal necrosis of myofibers of the heart was observed in males at 25 ppm after 125 exposures.

HISTOPATHOLOGY: NEOPLASTIC
Neoplastic lesions included nephroblastoma in one female at 25 ppm after 30  exposures, one pituitary adenoma in one male at 247 ppm after 125 exposures, and one thyroid follicular cell adenoma in one control female after 125 exposures.

OTHER FINDINGS: ELECTROPHYSIOLOGY:
No statistically significant differences were observed in any of the indices which were recorded and analyzed from rats exposed to either TEA concentration for 28 weeks.

Dose descriptor:

NOAEC

Remarks:

systemic effects

Effect level:

1 020 mg/m³ air

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: No statistically significant effects or effects related to treatment were observed in any parameter tested

Dose descriptor:

NOAEC

Remarks:

local effects and irritation

Effect level:

103 mg/m³ air

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: no effects

Dose descriptor:

LOAEC

Remarks:

eyes and nose irritation

Effect level:

1 020 mg/m³ air

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: irritation effects

Critical effects observed:

not specified

Vapor Exposure:

The TEA chamber concentrations for the 28-week exposure period were 24.8 ± 1.3 and 247.3 ± 11.5 (x ± SD). Rats were exposed at 25 or 247 ppm TEA for a maximum of 127 days, with an average of 5.80 and 5.82 hrs of exposure per day, respectively.

Cardiotoxicity:

There was no cardic muscle degenerations or any changes in electrocardiogramms.

Conclusions:

Triethylamine did not induce systemic toxicity in rats if inhaled.

Executive summary:

Male and female F-344 rats were exposed at 0, 25, or 247 ppm triethylamine (TEA) vapor, 6 hr per day, 5 days per week for up to 28 weeks in order to characterize the subchronic organ system toxicity. Rats were weighed biweekly and scheduled sacrifices were performed following about 30, 60, and 120 days of exposure. No statistically significant treatment-related effects on organ weights, hematology, clinical chemistry, or electrocardiographic indices were observed. Body weight gain was not affected by TEA treatment. No physiologic or pathologic evidence of cardiotoxicity was seen in rats exposed to either TEA concencentrations for up to 28 weeks. No gross or histopathological lesions attributable to TEA exposure were noted in any of the organs examined, including the nasal passages.

Based on the study results 25 ppm (corresponds to 103.3 mg/m³) is considered to be a NOAEC for local effects and irritation, while 247 ppm, the highest concentration tested (corresponds to 1020 mg/m³), repesents a NOAEC for systemic effects and simultaneously a LOAEC for eye and nose irritation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

1 444.4 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

good quality

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No GLP. Acceptable well documented publication which meets basic scientific principles.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 452 (Chronic Toxicity Studies)

Deviations:

yes

Principles of method if other than guideline:

In the present study only two dose levels were used in addition to the concurrent control group. The duration of the study is 28 weeks. Not all examinations are performed.

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:

Strain:Weanling caesarean-derived Fisher F344 [CDF (F-344)/Crl BR]
Rats were screened for serological evidence of Mycoplasma pulmonis infection prior to the initiation of exposures and all results were negative.
- Source: Charles River breeding Laboratories, Wilmington MA
- Age at study initiation: not reported
- Weight at study initiation: not reported
- Fasting period before study: no
- Housing: individually
- Diet (e.g. ad libitum): except during the exposure periods.
- Water (e.g. ad libitum): except during the exposure periods.
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Air changes (per hr): 12-15/hour
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

not specified

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Exposures were conducted in three 4.5 m³ stainless steel and glass inhalation chambers (Hinners et al., 1968) operated under dynamic flow conditions.

- Temperature, humidity in air chamber: 23 ± 3°C and 50 ± 10% RH, respectively.
- Air flow rate: 12-15 air changes per hr
- Treatment of exhaust air: A fresh batch of TEA was used in the generation reservoir each day.

TEST ATMOSPHERE
- Brief description of analytical method used: Wilks-Miran 1A Infrared Analyzer (Foxboro Analytical, Norwalk, CT) using the following instrument settings: wavelength 9 µm, pathlength 6.2 m, slit 1.0 mm. The instrument was calibrated by the closed loop calibration method. Adjustments were made to the generation system, as required, to maintain the exposure levels at the targeted concentrations.
- Samples taken from breathing zone: yes. TEA concentrations in the chamber were monitored 2-4 times per hour using a Wilks-Miran 1A Infrared Analyzer (Foxboro Analytical, Norwalk, CT)

VEHICLE (if applicable) no

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

2-4 times/hour with a Wilks-Miran Infrared Analyzer

Duration of treatment / exposure:

28 weeks

Frequency of treatment:

6 hours/day, 5 days/week

Remarks:

Doses / Concentrations:
0, 25 and 247 ppm  (0, 103 and 1020 mg/m³)
Basis:
nominal conc.

No. of animals per sex per dose:

50/sex/dose

Control animals:

yes

Details on study design:

- Dose selection rationale: Exposure concentrations were selected to provide comparisons to previous toxicity determinations conducted in this laboratory with diethylamine at 25 and 250 ppm (Lynch et al., 1986).
- Rationale for animal assignment (if not random): randomised

Positive control:

no

Observations and examinations performed and frequency:

Observations: Twice daily observations were made for changes in appearance or demeanor. Body weights were recorded on the day preceding the first day of exposure, at 2-week intervals throughout the study (at the end of an exposure day), and immediately prior to scheduled sacrifice.

Sacrifice and pathology:

10/sex/treatment sacrificed after ~30 and ~60 days of exposure, 20 after  ~ 125 days of exposure (10 in controls) 

GROSS PATHOLOGY: Yes
A complete necropsy was performed, and lungs, liver, kidneys, and heart were weighed.

HISTOPATHOLOGY: Yes
The following tissues were examined histologically: lungs (following infusion with 10% formalin), liver, kidneys, heart, spleen, tracheobronchial lymph nodes, adrenals, urinary bladder, testes, seminal vesicles, uterus, ovaries, trachea, eyes and nasal passages (processed and cut as described by Buckley et al. 1985).

Other examinations:

Clinical Chemistry-Hematoiogy:
The following clinical chemistry indices were measured at each scheduled sacrifice on a Gemsaec Centrifugal Analyzer (Electro-Nucleonics, Inc., Fairfield, NJ): alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine phosphokinase (CPK), blood urea nitrogen (BUN), creatinine (CRE) and sorbitol dehydrogenase (SDH). Hematology evaluations, conducted only at the terminal sacrifice, included hemoglobin, hematocrit, complete blood count and differential;

ECG were recorded at terminal sacrifice in 9-11 rats/sex/treatment

Statistics:

Multiple t-tests were used to compare initial body weights, while a multivariate analysis of variance was used to compare weight gains at each additional weighing period. Organ weights, organ-to-body weight ratios, hematology, clinical chemistry and electrocardiographic indices of the groups were compared by sex and length of exposure using the Kruskal-Wallis test (Hollander and Wolfe, 1973). Pathology incidence data were evaluated using a x² test. All comparisons between control and exposed animals were made at a statistical significant level of a = 0.05. Results were considered significant when p < 0.05.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

clinical signs

Mortality:

mortality observed, treatment-related

Description (incidence):

clinical signs

Body weight and weight changes:

no effects observed

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:

no effects observed

Description (incidence and severity):

no statistical difference

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

only sporadic changes

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

no statistical difference

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

no statistical significance

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

but unrelated to chemical exposure

Details on results:

CLINICAL SIGNS AND MORTALITY:
Rats of both sexes tolerated the exposure at 25 ppm without exhibiting overt signs of toxicity. At 247 ppm TEA the rats kept their eyes closed and noses buried in their fur during the entire exposure period.
All rats survived the exposures except for one female rat in the 25 ppm TEA group which was sacrificed due to malocclusion (week 6), two 250 ppm TEA female rats which died following an accidental injury (week 3), and one 250 ppm male rat which died during the exposure period (week 8). These deaths could not be attributed to TEA exposure.

BODY WEIGHT AND WEIGHT GAIN
Body weight was not statistically affected; however there was a slight dose-related reduction which occured in the TEA exposed male rats compared to the control

HAEMATOLOGY
Hematologic analyses revealed no statistical differences in male or female rats exposed to TEA for 28 weeks.

CLINICAL CHEMISTRY
Several clinical chemistry indices, i.e. SDH, ALT and creatinine, were elevated in one group of rats, or in only one sex of rats, at one of the scheduled interim sacrifices. These changes were not attributed to TEA exposure since they were sporadic in occurence and not concentration related.

ORGAN WEIGHTS
No consistent statistically significant differences in absolute or relative organ weights were seen in rats exposed to TEA and killed at any of the sceduled sacrifices. Lung weights and lung-to-body weight ratios were increased in all four groups of male and female rats exposed to TEA for 28 weeks, and absolute heart weights were increased in both groups of male rats exposed to TEA for the same period.

GROSS PATHOLOGY
There were no gross pathologic observations in rats which were considered to be related to treatment.

HISTOPATHOLOGY: NON-NEOPLASTIC
Chronic inflammation of the lungs was seen in all treated and control animals  exposed for 28 weeks. Liver lesions consisiting of minimal foci of necrosis were detected in males of all three groups exposed for 28 weeks. Minimal focal necrosis of myofibers of the heart was observed in males at 25 ppm after 125 exposures.

HISTOPATHOLOGY: NEOPLASTIC
Neoplastic lesions included nephroblastoma in one female at 25 ppm after 30  exposures, one pituitary adenoma in one male at 247 ppm after 125 exposures, and one thyroid follicular cell adenoma in one control female after 125 exposures.

OTHER FINDINGS: ELECTROPHYSIOLOGY:
No statistically significant differences were observed in any of the indices which were recorded and analyzed from rats exposed to either TEA concentration for 28 weeks.

Dose descriptor:

NOAEC

Remarks:

systemic effects

Effect level:

1 020 mg/m³ air

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: No statistically significant effects or effects related to treatment were observed in any parameter tested

Dose descriptor:

NOAEC

Remarks:

local effects and irritation

Effect level:

103 mg/m³ air

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: no effects

Dose descriptor:

LOAEC

Remarks:

eyes and nose irritation

Effect level:

1 020 mg/m³ air

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: irritation effects

Critical effects observed:

not specified

Vapor Exposure:

The TEA chamber concentrations for the 28-week exposure period were 24.8 ± 1.3 and 247.3 ± 11.5 (x ± SD). Rats were exposed at 25 or 247 ppm TEA for a maximum of 127 days, with an average of 5.80 and 5.82 hrs of exposure per day, respectively.

Cardiotoxicity:

There was no cardic muscle degenerations or any changes in electrocardiogramms.

Conclusions:

Triethylamine did not induce systemic toxicity in rats if inhaled.

Executive summary:

Male and female F-344 rats were exposed at 0, 25, or 247 ppm triethylamine (TEA) vapor, 6 hr per day, 5 days per week for up to 28 weeks in order to characterize the subchronic organ system toxicity. Rats were weighed biweekly and scheduled sacrifices were performed following about 30, 60, and 120 days of exposure. No statistically significant treatment-related effects on organ weights, hematology, clinical chemistry, or electrocardiographic indices were observed. Body weight gain was not affected by TEA treatment. No physiologic or pathologic evidence of cardiotoxicity was seen in rats exposed to either TEA concencentrations for up to 28 weeks. No gross or histopathological lesions attributable to TEA exposure were noted in any of the organs examined, including the nasal passages.

Based on the study results 25 ppm (corresponds to 103.3 mg/m³) is considered to be a NOAEC for local effects and irritation, while 247 ppm, the highest concentration tested (corresponds to 1020 mg/m³), repesents a NOAEC for systemic effects and simultaneously a LOAEC for eye and nose irritation.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

146.2 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

good quality

Additional information

Detail information on read-across:

There is no reliable repeated dose toxicity study on tri-n propylamine (TnPA) available. To assess systemic toxicity of tripropylamine read-across from closely related substances TEA , TBA and TMA was conducted.

The toxicity data on related substances per route of exposure are described below.

Oral toxicity

No reliable repeated dose toxicity studies by oral route of exposure exist for TEA and TBA. The available studies are restricted to their reliability, provide insufficient information about methodology and do not allow drawing a definite conclusion about toxicity after repeated exposure.

TEA

Kagan exposed rats (strain is unspecified) orally to TEA at different dose levels and during different exposure times. In 6-months experiment rats were treated with 0.1, 1.0 and 10 mg/kg bw of TEA. At 1.0 mg/kg bw minimal changes in reflexes were observed (Kagan, 1965). In 2.5-month oral study, retarded growth and increased ascorbic acid values in the liver were reported in treated animals exposed to 50 mg/kg bw. In 7-month experiment, exposure of rabbits per oral to 6 mg/kg resulted in no effect on the protein synthesis in liver, the activity of the serum cholinesterase and the SH-content. In the latter test, effects on the carbohydrate metabolism in the liver were described after 3-4 months (Kagan, 1965). In the TSCA submission to US EPA rats were exposed by gavage to 5, 15, 30, and 60 mg/kg of TEA three times a week for a total 18 applications in 6 weeks. No effects reported for animals treated with 5 and 15 mg. Convulsions were reported for animals treated with 30 and 60 mg/kg bw. Cramps were observed in animals treated with 60 mg/kg bw. Three deaths were reported for female animals treated with 60 mg/kg bw. One female at 60 mg was emaciated. Males in 60 mg/kg group lost weight and observed to have slightly roughened and yellowed coats. No significant deviations from normal were found in any rats and there were no histopathological findings other than caustic burn of the stomach.

TBA

20 Wistar rats of unspecified sex were treated orally by gavage with 152 mg/kg bw/day of tributylamine for 40 days. There were no effects with respect to mortality, body weight gain, clinical signs of toxicity or thyroid symptom as well as histology (Gandini and Merli, 1965). Rats of unspecified strain and sex were treated orally with 0.45 or 4.5 mg/kg bw/day daily for 6 months. No effects with respect to general constitution, behaviour or histology were observed (Din Min, 1977). Rabbits of unspecified strain and sex were treated orally with 0.61 or 6.1 mg/kg bw/day daily for 6 months. There were no effects with respect to general constitution, behaviour or histology. At 6.1 mg/kg, there was an increase in the prothrombin time and a decrease in the activities of the monoamine oxidase and the diamino oxidase as well as a reduction of the agglutinin titre (Din Min, 1977).

A reliable developmental study (Mitterer, 1991; Report No. 6031/90) conducted with tributylamine reported a LOAEL for maternal toxicity of 0.25% in food (165-500 mg/kg bw/day) and a NOAEL was 0.12 % (79-228 mg/kg bw/day). However, the examinations in this study focus on reproduction and developmental effects rather than systemic repeated dose effects. Details of this study are reported below and also in chapter 7.8.

Prenatal developmental study conducted with tributylamine (CAS No. 102 -82 -9)

Pregnant Sprague-Dawley rats (20 per group) were orally treated (purity of test item: 99.3%) by gavage on gestation days 6 -15 with doses of 15, 45 and 135 mg/kg/day (Mitterer, 1991). Maternal effects were observed only in the highest dose group. Three dams died prematurely on days 7 and 8. These animals showed red discoloration of the lungs. The other animals of this group showed transient reductions in food consumption and body weight gain. The LOAEL for maternal toxicity was 135 mg/kg bw/day, the NOAEL 45 mg/kg bw/day.

TMA

There is a reliable combined repeated dose toxicity study with reproduction/developmental screening test is available for TMA. The study was performed according to the OECD guideline 422 and considered suitable to be used in read-across.

Combined repeat dose and reproductive/developmental toxicity screening test conducted with trimethylamine (CAS No. 75 -50 -3)

13 male and female rats (Sprague-Dawley) each were exposed to a daily oral administration of trimethylamine at 0, 8, 40 or 200 mg/kg bw (in water) by gavage (Takashima et al., 2003). This resulted in the death of two males and 1 female administered 200 mg/kg/day. Abnormal breathing noise, salivation immediately after the administration, ulcers and inflammatory changes in the stomach and intestinal tracts, squamous hyperplasia and oedema in submucosa were observed in both males and females in the 200 mg/kg/day group. An inhibition tendency in body weight increase, decrease in food consumption, total protein concentration and albumin concentration were also observed in the males in the same group. There was no effect of trimethylamine administration on body weights and food consumption in the 200 mg/kg bw/day females or on organ weights, urine examination and hematological examination results in the males and females. Therefore it was inferred that the general NOAEL for systemic toxicity (No Observed Adverse Effect Level) is 40 mg/kg/day (Takashima et al., 2003).

Inhalation toxicity

Inhalation is the most suitable route of exposure for tertiary amines. The following repeated dose toxicity studies were used for read-across:

Subchronic inhalation of triethylamine vapour (CAS No. 121 -44 -8) in Fischer-344 rats: organ systemic toxicity

In a subchronic inhalation study to vapour of triethylamine Fischer-344 rats were exposed to 0, 25 and 247 ppm, 6h/day, 5 days/week for 28 weeks (Lynch et al., 1990). No adverse effects related to treatment were observed in treated animals. One male rat died during exposure period (8 week), the other deaths (1 female at 25 ppm, week 6, 2 females at 247 ppm, week 3, accidentally) were considered to be not treatment related. The body weight gain was slightly reduced in males (dose-related). No hematologic influences and additionally only incidental changes in clinical chemistry (ALAT, creatinine and sorbitol dehydrogenase) were found in treated animals. Chronic inflammations of lungs, liver lesions and neoplastic lesions were observed in all groups, including the controls. "At 247 ppm TEA the rats kept their eyes closed and noses buried in their fur during the entire exposure period" (Lynch et al., 1990). These findings could not be attributed to chemical exposure (argued by the author). According to the author the lung lesions were associated with viral infection. Any neoplastic lesions in the experimental animals were not associated with exposure to the test substance. Triethylamine exposure also led to degeneration of heart muscle fibres (males, 25 ppm after 125 exposures), but since this degeneration was only minimal and occurred so late in the exposure period, one cannot ascribe importance to this findings. Additionally no changes in electrocardiograms were found.

Based on the study results 25 ppm (corresponds to 146.2 mg/m³ for TnPA) is considered to be a NOAEC for local effects and irritation, while 247 ppm, the highest concentration tested (corresponds to 1444.4 mg/m³ for TnPA), represents a NOAEC for systemic effects and simultaneously a LOAEC for eye and nose irritation. The conversion of ppm to mg/m³ was performed according to the formula presented in ECHA guidance R7.A: mg/m³ = (MW x ppm)/ 24.5mg/m³ where MW of 143.27 for TnPA was used and 24.5 mg/m³ is the volume of ideal gas at 25°C.

Pathologic findings in Fischer 344 rats by inhalation to allylamine, ethylamine, diethylamine and triethylamine (CAS No. 121 -44 -8) with cover letter dated 042484

A subacute repeated dose toxicity test with triethylamine was performed by inhalation with rats (Fischer 344) (Lynch et al., 1984). The exposure time was 10 days, the exposure was performed for 6 hours per day on 5 days of the week. A concentration of 1000 ppm (4.319 mg/L) was chosen.

All 10 animals had at least moderate (grade 3) necrotizing inflammation of the nasal cavity. Progression of effects deeper into the respiratory tract was indicated by the occurrence of squamous metaplasia (from slight to marked in severity) in the trachea in 7 of 10 animals. Moderate thymic atrophy was present in 7 of 10 animals. Keratitis (graded as slight) was noted in three animals. Two of the males and one of the females died after the seventh day of exposure. Lung effects (perivascular edema) were noted but only in the three animals that died.

Although the cause of death is not indicated by the authors, the mortality may be related to the pulmonary oedema observed and not due to systemic effects caused by the compound (IRIS Summary Record, substance name: Triethylamine CAS RN: 121-44-8 (Cited in NISC).

The subacute inhalation toxicity of 109 industrial chemicals

A sub-acute inhalation study conducted with TBA (Gage, 1970, Study No. T02500) possess deficiencies in data reporting and methodology (use of a solvent for the two lower exposure levels with unknown influence on neurotoxic symptoms, low number of animals, no data on control animals, no analysis of the exposure concentration). Therefore, no conclusions can be drawn from the results of this study. The exposure to 29, 62 and 120 ppm of tributylamine (223, 477 and 923 mg/m³, respectively, 19 exposures, 6 h/d, 5 d/w) produced slight lethargy in Alderley-Park rats at the lowest tested concentration of 29 ppm (Gage, 1970) The effects were more pronounced at 62 ppm and the animals showed no weight gain. Petrolether was used as solvent for these two lower exposures. At 120 ppm the animals showed nose irritation, restlessness, incoordination, tremors and no weight gain. The organs revealed no abnormalities.

7 -month chronic experiment conducted with trimethylamine (CAS No. 75 -50 -3)

Rotenberg and Mashbits studied TMA inhalation exposure in a 7-month chronic experiment (Rottenberg and Mashbits, 1967). Two groups of animals (12 male white rats/group) were exposed 5 hours/day to TMA at 10.4 ppm (25.0 mg/m³) or 31.0 ppm (75.0 mg/m³). Male rats from the third group were used as control. During exposure, air samples were taken 3-4 times a day and TMA levels determined (the chemical and analytical detection was performed with colorimetric methodology, based on the occurrence of yellow coloration when a TMA aqueous solution is in the presence of ortho-nitrophenol). Excitation and aggressiveness were manifested for 3-4 weeks after the beginning of the experiment. For the first exposure month, diarrhoea was observed during the first 2-3 hours of each exposure. Lymphocytes count decreased and the number of neutrophils increased in rats from the 31.0 ppm group beginning from the 4th exposure month onward. No statistically significant deviations between experimental and control groups were revealed when the following data were analysed: body weight, oxygen consumption, emission of carbon dioxide, protein fractions in the blood, antitoxic function of the liver (Quick’s – Pytel’s Test), and the threshold for nervous and muscular excitability. Pathomorphological studies showed animals from the 31.0 ppm group exhibited bronchopneumonia and haemorrhage in the pulmonary tissue with destruction of interalveolar layers, and isolated hemorrhage in the liver, kidneys and spleen. Rats from the 10.4 ppm group had similar changes but they were less pronounced. The only statistically significant change in relative organ weight was an increase of the adrenal gland weight of rats exposed to 31 ppm (cited in the "Acute Exposure Guideline levels (AEGLs) for trimethylamine (CAS reg. No. 75 -50 -3) Interim 06/2008"). According to the study results, 25 mg/m³ is considered to be a LOAEC.

Subacute Inhalation study conducted with trimethylamine (CAS No. 75 -50 -3)

E. I. du Pont de Nemours & Company performed a subacute test on male rats with trimethylamine by the route of inhalation (du Pont, 1983; Report No. 763 -82). The test duration was 14 days, the frequency of dosage was 6 hours per day, 5 days a week. The test substance concentrations were 74, 240 and 760 ppm (corresponds to 179, 579 and 1834 mg/m³, respectively). No clinically significant changes were observed in rats exposed to 74 ppm at either sacrifice. Organ to body weight ratio analyses after 10 exposures revealed significant increases in lung to body and heart to body weight ratios in rats exposed to 760 ppm. There were no significant differences in mean organ weights and organ to body weight ratios after the 14-day recovery period. After 10 exposures, rats exposed to 240 and 760 ppm exhibited a dose-related increase in erythrocyte count and decrease in mean corpuscular haemoglobin. In addition, rats exposed to 760 ppm exhibited increases in haemoglobin concentration, haematocrit, platelet count, absolute number of neutrophils, and serum concentrations of urea nitrogen, protein and creatinine. Some of these effects represent treatment-related polycythaemia in rats exposed to 240 and 760 ppm, and dehydration in rats exposed to 760 ppm.

Pathological examination after 10 exposures demonstrated a dose-related irritation to the nasal cavity and turbinates in all exposed rats. This irritation ranged in severity from very mild in rats exposed to 74 pp, to moderate in rats exposed to 760 ppm. In addition, rats exposed to 760 ppm exhibited compound-related tracheitis/necrosis and lungs with mild emphysematous alveoli after 10 exposures. Following the 14-day recovery period, nasal cavity and turbinate irritation was still detected in all exposed rats, with severity reduced only in the 760 ppm rats. The tracheal and lung effects were reversible after 14 days recovery. A no-effect level was not established for repeated inhalation of anhydrous trimethylamine. However, rats exposed to 74 ppm exhibited only very mild irritation to the nasal cavity and turbinates, which did persist through the 14 -day recovery period.

Based on the results of this study, 74 ppm is considered to be a LOAEC.

Dermal toxicity

Due to corrosivity of the tertiary amines, no dermal repeated dose toxicity studies are available.

Conclusion

Repeated oral exposure by gavage to TMA resulted in local effects in the gastrointestinal tract (inflammation in stomach and intestines). NOAEL of 40 mg/kg bw/day was established (Takashima, 2003). Reduction in body weight and food consumption were characteristically for TMA (at the 200 mg/kg bw) and for TBA (at the 135 mg/kg bw in the developmental study, Mitterer, 1991). No remarkable systemic toxic effects were noted in these studies. Burns in stomach was reported also in old unreliable oral repeated studies conducted with TEA.

Repeated inhalation of TEA, TBA and TMA resulted in respiratory local toxicity. Chronic inflammation of lungs (TEA), nose irritation (TMA and TBA), necrotizing inflammation of the nasal cavity and squamous metaplasia in the trachea (TEA) as well as haemorrhage in the pulmonary tissue with destruction of interalveolar layers (TMA) were observed in exposed animals. A NOAEC of 103.3 mg/m³ for respiratory local effects and irritation was established for TEA, and a LOAEC of 25 mg/m³ for local effects and irritation was established for TMA. No respiratory systemic effects were noted at the concentration of 1020 mg/m³ of TEA (NOAEC).

Comparing the dose levels and concentrations at which no effects were seen in treated animals, it is apparent that they are different by three alkylamines, while local irritation effects are common property characteristically for all alkylamines. The local effects appeared first but systemic effects were not detected. The clinical signs such as decrease of body weight and food intake can be connected to the local irritating effects. In other words, local irritation effects dominate over systemic effects and the doses which would produce systemic effects cannot be achieved. This observation allows a qualitative read-across of data between alkylamines. Instead of quantitative read-across of a NOAEL or a NOAEC, which are normally needed to be used in the derivation of DNELs, a comparison of existing German MAK or OEL values for other alkylamines is proposed. MAK values for most of tertiary amines are 2 ppm, except of TEA for which 1 ppm is established as safe industrial concentration (TRGS 9000, 2006). Therefore, a conservative German MAK value of 1 ppm is proposed for TnPA as long-term inhalation DNEL for workers (please refer to section 5.11.2 of CSR or section 7 of IUCLID file regarding detailed information on justification of MAK value).

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
Reliable combined repeated dose study with reproduction screening test conducted with a nearest analogue TMA (study duration 42 days).

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
Reliable subchronic study conducted with a nearest structural analogue TEA.

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
Reliable subchronic study conducted with a nearest structural analogue TEA.

Justification for classification or non-classification

Due to the corrosivity of TNPA and the fact that local effects prevail over systemic effects in the repeated toxicity studies conducted with analogue chemicals, classification is not warranted for STOT-RE according to the criteria of EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.