N,N,N',N'-tetramethylethylenediamine

Endpoint summary

Description of key information

An acute oral toxicity study is available for the submission substance (BULAB 600 / TMEDA).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 to 27 June 2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

No evidence of GLP compliance

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Deviations:

no

GLP compliance:

no

Remarks:

The report was signed by the Study Director declaring that the methods, results and data in the report relected the procedures used and the raw data collected during the study.

Test type:

up-and-down procedure

Limit test:

no

Specific details on test material used for the study:

BULAB 600
Lot number 46903
Clear, colourless to light yellow liquid

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

Source: Harlan
Housing: Individually in suspended stainless steel cages with mesh floors.
Photoperiod: 12 hours light/dark cycle
Food: Harlan Teklad Global 16% protein rodent diet 2016
Water: Filtered tap water, ad libitum

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

Animals were fasted overnight. Eight female animals were tested. Test material was administered as received. The first animal was administered 175 mg/kg bw test material by oral gavage. Seven additional females were dosed at levels of 175, 550 or 2000 mg/kg bw using the Up and Down procedure. Doses were administered using a stainless steel ball tipped gavage needle. After administration, animals were returned to their cages. Food was replaced 3-4 hours after dosing.

Doses:

175, 550 or 2000 mg/kg bw

No. of animals per sex per dose:

175 mg/kg bw (3 females); 550 mg/kg bw (4 females); 2000 mg/kg bw (1 female)

Control animals:

no

Details on study design:

All animals were observed for mortality, signs of gross toxicity and behavioural changes at least once daily for 14 days after dosing. Body weights were recorded prior to administration and again on Day 14 (termination) following dosing or after death. Animals were euthanised by carbon dioxide inhalation at termination. A gross necropsy was performed on all animals.

Statistics:

Not required

Preliminary study:

Not performed

Key result

Sex:

female

Dose descriptor:

approximate LD50

Effect level:

550 mg/kg bw

Based on:

test mat.

95% CL:

> 196.4 - < 884

Mortality:

No animals died at the lowest dose of 175 m/kg bw. Three of the four animals died at the mid dose of 550 mg/kg bw within one day of administration. At the highest dose of 2000 mg/kg bw, the single animal died within one hour of administration.

Clinical signs:

other: At the low dose of 175 mg/kg bw, animals appeared healthy with the exception of ano-genital staining and reduced faecal volume which was noted for one animal on Day 1. At the mid dose of 550 mg/kg bw, oral and ocular discharge, irregular respiration, hyp

Gross pathology:

No abnormalities were noted for the animals dosed with 175 mg/kg bw. Following gross necropsy of the decedents at 550 mg/kg bw, discoloration of the lungs, liver, stomach, intestines and/or spleen and distention of the stomach and intestines were observed. No gross abnormalities were noted for the euthanised animal necropsied at the conclusion of the 14-day observation period. Gross necropsy of the decedent at 2000 mg/kg bw revealed discoloration of the lungs, stomach, spleen, liver and intestines and distention of the intestines.

Clinical observations

Observations	175 mg/kg bw	550 mg/kg bw	2000 mg/kg bw
Ano-genital staining	1/3	2/4	0/1
Reduced faecal volume	1/3	1/4	0/1
Irregular respiration	0/3	3/4	0/1
Hypoactivity	0/3	4/4	0/1
Ataxia	0/3	4/4	0/1
Ocular discharge	0/3	2/4	0/1
Nasal discharge	0/3	1/4	0/1
Oral discharge	0/3	1/4	0/1
Hunched posture	0/3	2/4	0/1
Mortality	0/3	3/4	1/1

Necropsy observations

Observations	175 mg/kg bw	550 mg/kg bw	2000 mg/kg bw
Red colouration of lungs	0/3	3/4	1/1
Red colouration of stomach	0/3	2/4	1/1
Red colouration of intestines	0/3	2/4	1/1
Red colouration of spleen	0/3	1/4	1/1
Red colouration of liver	0/3	1/4	0/1
Mottled liver	0/3	0/4	1/1
Distention of stomach	0/3	2/4	0/1
Distention of intestines	0/3	3/4	1/1

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The LD50 of BULAB 600 was estimated to be 550 mg/kg bw with a 95% confidence interval of 196.4-884 mg/kg bw.

Executive summary:

An acute oral toxicity study was conducted with BULAB 600 (TMEDA) based on the Up and Down method (OECD TG425). Sprague Dawley rats were dosed with a starting dose of 175 mg/kg bw: there were no mortalities and gross pathology findings, although some clinical findings (ano-genital staining and reduced faecal volume) were noted in a single animal on Day 1. At 550 mg/kg bw, three of the four animals died within 1 day of dosing. Decedent animals dosed with 550 mg/kg bw showed clinical signs prior to death of oral and ocular discharge, irregular respiration, hypoactivity, hunched posture, ataxia and ano-genital staining. The surviving rat dosed with 550 mg/kg bw exhibited nasal discharge, hyopactivity, ano-genital staining, ataxia and reduced faecal volume following administration but recovered from these symptoms by Day 3. This animal appeared healthy for the remainder of the observation period. A single animal dosed with 2000 mg/kg bw died within 1 hour of dosing; no clinical signs were observed. Discoloration of the lungs, liver, stomach, intestines and/or spleen and distention of the stomach and/or intestines were observed in decedent animals at 550 and 2000 mg/kg bw. No gross abnormalities were noted for the euthanised animal dosed with 550 mg/kg bw necropsied at the conclusion of the 14-day observation period. The LD50 of the test material was estimated to be 550 mg/kg bw with a 95% confidence interval of 196.4 -884 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

550 mg/kg bw

Quality of whole database:

The study is considered to be reliable as although not conducted to GLP, it was conducted in a GLP certified laboratory.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

23 September to 23 October 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study was performed to determine the potential for Bulab 600 to produce toxicity from a single 1-hour inhalation exposure.

GLP compliance:

no

Test type:

traditional method

Limit test:

no

Specific details on test material used for the study:

Bulab 600
Lot 0-5201

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Source: Charles River Breeding Laboratories
Housing: Individually housed
Temperature controlled
Food: Purina rat chow, ad libitum except during exposure
Water: Madison city well water, ad libitum except during exposure
Age at experimental start: 8 weeks
Weight at experimental start: 158-240 g
Acclimatisation period: 7 days

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Remark on MMAD/GSD:

Particle size not measured.

Details on inhalation exposure:

The initial screen level was conducted at a nominal concentration of 69100 mg/m^3 of air for 1 hour and the second level at 17900 mg/m^3 of air for 1 hour. The time for equilibration (90% of desired concentration) was 14 minutes for 69.1 mg/L of air and 8 minutes for 17.9 mg/L of air thereby the exposure time was 74 and 68 minutes, respectively. Administration of the test material was during only the initial 60 minutes. The test exposures were conducted with samples of the test material in which each contained the same concentration of formulated ingredients. The test material was administered directly into the chamber using the Spraying Systems unit which was equilibrated prior to conducting the exposure by running the unit and calculating the dispersion rate several times. The unit was checked for variation in the rate of dispersion periodically during the exposure period. Exposures were conducted in an 842 L stainless steel semi-portable exposure chamber which was equipped with an exhaust port which was connected to an exhaust fan, providing an adjustable air flow through the chamber. Air flow was determined by a calibrated pressure gauge which measured the pressure drop across a defined inlet orifice. The test material was administered into the chamber near the junction for the air inlet pot, which allows the test material and incoming air to mix evenly within the chamber at the top before being drawn down over the animals.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

1 h

Remarks on duration:

Equilibration time was 14 minutes for high dose and 8 minutes for low dose

Concentrations:

17900 and 69100 mg/m^3 of air for 1 hour, equivalent to 17.9 and 69.1 mg/L of air

No. of animals per sex per dose:

Five

Control animals:

yes

Details on study design:

Animal observations were recorded periodically during exposure. Immediately following and up to 1 hour after exposure to the compound, the animals were observed for pharmacotoxic signs and mortality. Thereafter, the animals were observed daily for 14 days for pharmacotoxic effects and mortality. Body weights for all animals were taken just prior to compound exposure and again at 7 and 14 days post exposure for survivors. Animals were sacrificed at 14 days. They were subjected to a gross necropsy examination and abnormalities were recorded.

Statistics:

Not required.

Preliminary study:

Not performed

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 17 900 - < 69 100 mg/m³ air

Based on:

test mat.

Exp. duration:

1 h

Mortality:

All animals died at 69100 mg/m3. No mortalities were observed at 17900 mg/m3 or for the control group.

Clinical signs:

other: In the control group, animals appeared normal through the exposure and post dose observation periods. In the low exposure concentration group (17.9 mg/L), shallow breathing, gasping, lacrimation, nasal discharge, oral discharge, red and irritated eyes we

Body weight:

Body weights were recorded, but body weight gain was not discussed in the report.

Gross pathology:

In the control group, the lungs of one female contained multiple (pinpoint to 2 mm) red foci, considered to be an incidental finding. There were no other gross lesions in the remaining nine animals. In the low dose group (17.9 mg/L), a focal (1-2mm) pale, opaque, firm, raised papule was observed on central corneas of each left eye of three males and one female and bilaterally in two females. The central corneas of another female contained a 4 mm, red and white, firm raised papule. Both kidneys of the fifth female contained moderate pelvic dilation which was considered to be incidental. In the high dose group (69 mg/L), there was darkening of the liver in two males and five females. Corneal opacity of the right eye of one male was observed. Mild hydrometra was observed in the uterus of one female, which was considered to be incidental. Two rats exhibited no significant gross lesions.

No futher information available.

Interpretation of results:

study cannot be used for classification

Conclusions:

The acute inhalation LC50 was between 17.9 and 69.1 mg/L for a 1-hour exposure. Using Haber's law (LC50 * 1h/4h), this equates to a 4-hour LC50 of between 4.5-17.3 mg/L. However there was no analytical verification of the achieved concentration and no measurement of particle size, therefore the actual exposure concentrations are unknown.

Executive summary:

In an acute inhalation toxicity study conducted with the substance TMEDA (Bulab 600), a group of Sprague Dawley rats (5/sex) was exposed to atmospheres containing nominal concentrations of 17900 or 69100 mg/m3 for 1 hour following equilibration. A control group was also tested. All animals exposed to 69100 mg/m3 died; however no mortalities were observed at 17900 mg/m3 or for the control group. In the low exposure group, shallow breathing, gasping, lacrimation, nasal discharge, oral discharge, red and irritated eyes were observed during the exposure period. During the 14-day observation period, the animals showed laboured breathing, nasal discharge, vasodilation and corneal changes. At necropsy, raised papules were observed on the corneas of seven animals. In the high exposure group (69 mg/L), laboured breathing, nasal discharge, convulsions and irritated eyes were observed prior to death. At necropsy, darkening of the liver was reported for two males and five females. Corneal opacity was observed in one animal. Two rats exhibited no significant gross lesions. The acute inhalation LC50 was between 17.9 and 69.1 mg/L for a 1-hour exposure.  Using Haber's law, this equates to a 4-hour LC50 of between 4.5-17.3 mg/L (LC50 * 1h/4h).  However there was no analytical verification of the achieved concentration and no measurement of particle size, therefore the actual exposure concentrations are unknown.

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

12 November 2012 to 16 May 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study was performed to determine the potential for ATMEDA-HP to produce toxicity from a single 30-minute exposure by inhalation (nose-only).

GLP compliance:

no

Remarks:

The report was signed by the Study Director declaring that the methods, results and data in the report relected the procedures used and the raw data collected during the study.

Test type:

fixed concentration procedure

Limit test:

no

Specific details on test material used for the study:

ATMEDA-HP
Lot numbers: C2012091200476, C2012111200162, C2013021200464 and C2013041200137
Composition: N,N,N',N'-Tetramethylethylenediamine >98.5%; CAS number 110-18-9
Storage: Ambient room temperature and humidity
Expiry date: Not applicable
Clear colourless to light yellow liquid
Soluble in water
Sample aerosolised as received

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Source: Harlan Laboratories, Inc.
Housing: Individually housed in suspended stainless steel cages with mesh floors with enrichment.
Temperature: 20-22 degrees C
Humidity: 55%
Photoperiod: 12 hours light/dark cycle
Food: Harlan Teklad Global 16% protein rodent diet 2016, ad libitum
Water: Filtered tap water, ad libitum except during the exposure
Age at experimental start: 9-10 weeks
Weight at experimental start: 278-286 g (males) 188-209 g (females)
Air changes: 11/hour
Acclimatisation period: 14 days

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

air

Remark on MMAD/GSD:

Particle size was not determined as exposure was to the vapour phase

Details on inhalation exposure:

Five males and five female rats were tested. The test material was administered by vapour inhalation via a nose-only exposure chamber (volume 6.7 litres). Animals were individually housed in polycarbonate holding tubes which sealed to the chamber. Approximately 18 L/min of filtered generator air was supplied by an air compressor measured with a mass flow controller or mass flow meter. An additional 6 L/min of filtered mixing air from the same air compressor was introduced into the chamber to help uniformly distribute the test atmosphere by creating a vortex at the chamber inlet. Compressed mixing airflow was measured with a mass flow meter. Chamber air was monitored throughout the exposure period and recorded periodically. Total airflow was 60 L/min. Based on the volume of the inhalation chamber, this airflow provided approximately 537 air changes per hour during the study. The exposure was conducted in slightly positive pressure. The exposure tube was 21-22 degrees C with 34-49% humidity and the room was 21 degrees C with 37-38% humidity during the exposure. Measurements were taken every 10-15 minutes.

The exposure period was 30 minutes. Pre-test trials were conducted to establish generation procedures to achieve the desired chamber concentration of 5000 ppm. The parameters used provided an analytical concentration of 5444.47 ppm. It was determined there were no measurable particles due to the nature of the test substance

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

30 min

Remarks on duration:

A 1-hour exposure was intended, however due to complete mortality after 30 minutes, the exposure was terminated.

Concentrations:

6361.30 ppm

No. of animals per sex per dose:

Five

Control animals:

no

Details on study design:

All animals were observed for mortality during the exposure period. The animals were examined for signs of gross toxicity and behavioural changes whilst in the chamber. Observations included gross evaluation of skin and fur, eyes and mucus membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behaviour pattern. Particular attention was directed to observations of tremors, convulsions, salivation, diarrhoea and coma. Gross necropsies were performed for all decedents following exposure termination. Tissues and organ of the thoracic and abdominal cavities were examined.

Statistics:

Not required beoyond calculation of the mean and standard deviation.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

< 6 361.3 ppm

Based on:

test mat.

Exp. duration:

30 min

Mortality:

All animals were dead within 30 minutes of the start of the exposure.

Clinical signs:

other: Due to the position in the exposure tubes, possible toxic signs were unable to be observed.

Body weight:

Body weight changes are not applicable as all animals died during the exposure.

Gross pathology:

Gross necropsy revealed discoloration of the lungs and/or intestines.

Other findings:

None.

Necropsy observations

Observations	Male	Female
Slightly red lungs	4/5	3/5
Moderately red lungs	1/5	2/5
Slightly red intestines	0/5	1/5

Interpretation of results:

study cannot be used for classification

Conclusions:

The 30 -minute acute vapour inhalation LC50 of ATMEDA-HP is therefore less than 6361.30 ppm. Using the standard conversion equation (i.e. mg/m3 = (ppm value) * molecular weight (116.2) / 2.7, 6361.30 ppm is calculated to be equivalent to ~32.5 mg/L. Using Haber's law, a 4-hour LC50 of <4 mg/L can be calculated (32.5 mg/L * 0.5h/4h

Executive summary:

An acute inhalation toxicity study was conducted with the submission substance (ATMEDA-HP). A group of Sprague Dawley rats (5/sex) were exposed to a single vapour concentration of 6361.30 ppm. Within 30 minutes of the planned 1 -hour exposure, all animals had died. No clinical observations were made during the exposure. Gross necropsy revealed discoloration of the lungs and/or intestines for all animals. The 30 -minute acute vapour inhalation LC50 of ATMEDA-HP is therefore less than 6361.30 ppm. Using the standard conversion equation (i.e. mg/m3 = (ppm value) * molecular weight (116.2) / 2.7, 6361.30 ppm is calculated to be equivalent to ~32.5 mg/L. Using an approximation method based on Haber's law, a 4-hour LC50 of <4 mg/L can be calculated (32.5 mg/L * 0.5h/4h).

Reference 3

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

23 July 1991 to 15 October 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study was designed to assess the acute toxic effects of Bulab 600 when administered by inhalation as a vapor to 10 Sprague Dawley rats for one hour.

GLP compliance:

yes

Test type:

traditional method

Limit test:

no

Specific details on test material used for the study:

Bulab 600
Lot number: ID-1927
Concentration: 99.6% active ingredient
Description: Clear colourless to pale yellow liquid
Expiry date: April 1992
Storage: 16-29 °C

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Supplier: Charles River Breeding Laboratories, Inc.
Age at exposure: 7 weeks (males); 8 weeks (females)
Body weight on day of exposure: 242-249g (males); 209 to 217g (females)
Acclimatisation period: 10 days
Housing: Doubly housed during first week of acclimatisation; individually housed for remaining period of acclimatisation and during non-exposure periods.
Food: Purina Rodent Laboratory Chow; ad libitum
Water: Tap water (Elizabethtown Water Company); ad libitum
Photoperiod: 12 hour light/dark cycle
Temperature: 20-23°C
Humidity: 48-78%

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

1.7 µm

Geometric standard deviation (GSD):

2.2

Details on inhalation exposure:

Approximately 250 g of the test substance was placed into a 750 mL Crown Glass bubbler. House-line air was delivered using a Union Carbide regulator and USG backpressure gauge via ¼ inch American Scientific Products tubing to a Drierite Laboratory Gas Drying Unit where it split into two flows of air, a generation airflow and a dilution airflow. The generation airflow of 8 L/min was delivered through a Nupro metering value, a Dwyer flowmeter and a Marshall Town backpressure gauge into the bubble. The vapour-laden air was then directed into a glass ‘T’ tube where it was mixed with the dilution airflow. The dilution airflow was delivered through a Nupro metering and a Dwyer flowmeter into the glass ‘T’ tube. The resultant vapour-laden air stream was directed from the glass ‘T’ tube into the inlet portal of the exposure chamber which housed the animals. The chamber was exhausted via ¾ inch American Scientific Products tubing into the in-house exhaust system. The animals remained in the chamber for 30 minutes following the exposure to allow the chamber to clear, using house-line air at the same airflow rate used during exposure. The level of Bulab 600 in the test atmosphere was recorded twice during the exposure. The particle size distribution measurements were performed twice during the exposure. The temperature, relative humidity, airflow rates and static pressure were recorded every half-hour during the exposure.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

60 min

Concentrations:

Mean: 4649 ppm; Standard deviation: 115 ppm
Measurements taken at 28 and 52 minutes (values were 4730 and 4567 ppm, respectively).

No. of animals per sex per dose:

Five

Control animals:

no

Details on study design:

Animals were observed individually immediately prior to exposure and as a group at approximately fifteen-minute intervals during exposure. All animals were observed individually upon removal from the chamber and hourly for two hours post-exposure. Thereafter, observations were recorded daily and viability was assessed twice daily. The body weight was recorded immediately prior to exposure, on Days 2, 3, 5, 8 and 15 (just prior to sacrifice). The animals were sacrificed by exsanguination under ethyl ether anaesthesia. Post-mortem examinations included the nasal passages, trachea, all orifices, the cranial cavity, the brain and spinal cord, the thoracic, abdominal and pelvic cavities and their viscera, and the cervical tissues and organs and the carcass.

Statistics:

Not required

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

4 649 ppm

Based on:

test mat.

Exp. duration:

1 h

Remarks on result:

other:

Remarks:

No deaths occurred during the exposure period

Mortality:

No mortalities during the exposure.

Clinical signs:

other: During the exposure, gasping, laboured breathing, excessive lacrimation and salivation, nasal discharge, eye closure and matted coat were observed. Upon removal from the chamber and during the two-hour post exposure observation period, in addition to the

Body weight:

Substantial weight loss (approximately 16%) was observed on the first two days following exposure. Recovery of weight occurred over time and all animals were in excess of this pre-exposure body weight by termination of the study.

Gross pathology:

A number of findings observed grossly occurred in the eyes and included roughening, opacity and tan areas which were considered to the treatment-related. Other macroscopic findings were considered to be sporadic in nature and were considered not to be treatment-related

Bodyweight recordings

	Day
	1	2	3	5	8	15
Mean male bodyweight (g)	245	213	207	215	239	312
Mean female bodyweight (g)	214	189	180	197	221	262

 

Necropsy findings

Finding	Male	Female
Eye- Discoloured	2/5	1/5
Eye- Opacity of the eye	5/5	4/5
Eye- surface irregularities	4/5	4/5
Eye - closed	1/5	0/5
Eye- Enophthalmic	1/5	0/5
Spleen - Discoloured	1/5	0/5
Uterus- Polyp(s)	N/A	1/5

 

Interpretation of results:

study cannot be used for classification

Conclusions:

No mortality was seen following exposure to a vapour concentration of 4649 ppm (23.8 mg/L). Using Haber's law (4649 ppm * 1h/4h), a 4-hour LC50 of 1162 ppm (5.9 mg/L) can be determined.

Executive summary:

A group of 10 Sprague-Dawley rats was exposed to the vapour of the substance ATMEDAHP (Bulab 600) by inhalation (whole-body) for one hour. No deaths occurred. Signs consistent with respiratory, secretory and ocular irritation were observed during the exposure period. Following the two week observation period, ocular lesions persisted and were confirmed post mortem. Transient effects on bodyweight were also observed. No mortality was seen following exposure to a vapour concentration of 4649 ppm (23.8 mg/L).  Using Haber's law (4649 ppm * 1h/4h), a 4-hour LC50 of 1162 ppm (5.9 mg/L) can be determined.  

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity

An acute oral toxicity study was conducted with BULAB 600 (TMEDA) based on the Up and Down method (OECD TG425). Sprague Dawley rats were dosed with a starting dose of 175 mg/kg bw: there were no mortalities and gross pathology findings, although some clinical findings (ano-genital staining and reduced faecal volume) were noted in a single animal on Day 1. At 550 mg/kg bw, three of the four animals died within 1 day of dosing. Decedent animals dosed with 550 mg/kg bw showed clinical signs prior to death of oral and ocular discharge, irregular respiration, hypoactivity, hunched posture, ataxia and ano-genital staining. The surviving rat dosed with 550 mg/kg bw exhibited nasal discharge, hyopactivity, ano-genital staining, ataxia and reduced faecal volume following administration but recovered from these symptoms by Day 3. This animal appeared healthy for the remainder of the observation period. A single animal dosed with 2000 mg/kg bw died within 1 hour of dosing; no clinical signs were observed. Discoloration of the lungs, liver, stomach, intestines and/or spleen and distention of the stomach and/or intestines were observed in decedent animals at 550 and 2000 mg/kg bw. No gross abnormalities were noted for the euthanised animal dosed with 550 mg/kg bw necropsied at the conclusion of the 14-day observation period. The LD50 of the test material was estimated to be 550 mg/kg bw with a 95% confidence interval of 196.4 -884 mg/kg bw. The GLP status of the study is unclear; however the study was performed in a reputable laboratory and in compliance with an appropriate guideline. It is also noted that testing of the substance can be waived on the basis of its classification for corrosivity.

Acute dermal toxicity

No data are available. Testing of the substance can be waived on the basis of its classification for corrosivity.

Acute inhalation toxicity

Three studies of acute inhalation toxicity are available, using 1 -hour exposure periods.

In the study of Durando (2013), a group of Sprague Dawley rats (5/sex) were exposed to a single vapour concentration of TMEDA of 6361.30 ppm. Within 30 minutes of the planned 1 -hour exposure, all animals had died. Gross necropsy revealed discoloration of the lungs and/or intestines for all animals. The 30 -minute acute vapour inhalation LC50 of ATEMDA-HP is therefore less than 6361.30 ppm (~32.5 mg/L); using an approximation method based on Haber's law, a 4-hour LC50 of <4 mg/L can be calculated.

In the study of Hoffman (1991), a group of 10 Sprague-Dawley rats was exposed to TMEDA vapour by inhalation (whole-body) at a concentration of 4649 ppm for one hour. No deaths occurred. Signs consistent with respiratory, secretory and ocular irritation were observed during the exposure period. Following the two week observation period, ocular lesions persisted and were confirmed post mortem. Transient effects on bodyweight were also observed.  Using Haber's law, a 4-hour LC50 of 1162 ppm (5.9 mg/L) can be determined (i.e. 4649 ppm * 1h/4h).  

In the study of Boynton (1981), a group of Sprague Dawley rats (5/sex) was exposed to atmospheres containing nominal concentrations of TMEDA at 17900 or 69100 mg/m3 for 1 hour following equilibration. All animals exposed to 69100 mg/m3 died; however no mortalities were observed at 17900 mg/m3. The acute inhalation LC50 was between 17.9 and 69.1 mg/L for a 1-hour exposure.  Using Haber's law (LC50 * 1h/4h), this equates to a 4-hour LC50 of between 4.5-17.3 mg/L.  However there was no analytical verification of the achieved concentration and no measurement of particle size, therefore the actual exposure concentrations are unknown.

Although LC50 values are reported for TMEDA, these relate to exposures of 30 minutes or 1 hour and not to a standard exposure period of 4 hours which is used as the basis for classification. While an estimation of the 4 -hour LC50 is possible using Haber's law, the applicability of this method for an irritant substance such as TMEDA is unknown. It is noted that the substance has a harmonised classification for acute inhalation toxicity in Category 4; furthermore no additional testing is required based on the classification of the substance for skin corrosivity.

Justification for classification or non-classification

The submission substance TMEDA (N,N,N'N'-tetramethylethylenediamine) has a harmonised classification for acute oral toxicity in Category 4. This classification is consistent with the findings of the acute oral toxicity study (LD50 550 mg/kg bw) and no change is proposed.

Although LC50 values are reported for TMEDA, these relate to exposures of 30 minutes or 1 hour and not to a standard exposure period of 4 hours which is used as the basis for classification. While an estimation of the 4 -hour LC50 is possible using Haber's law, the applicability of this method for an irritant substance such as TMEDA is unknown. It is noted that the substance has a harmonised classification for acute inhalation toxicity in Category 4; no change to this classification is proposed.