Registration Dossier

Administrative data

Description of key information

The acute oral LD50 of the susbtance in mice is 14.5 g/kg bw. The acute 4-hour inhalation LC50 of the substance is >5.15 mg/L in rats.  A waiver is proposed for dermal toxicity.  

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:
June - August 1979
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
No reference is made to official Test Guidelines and no claim is made to GLP compliance. Furthermore, there is no reference to the purity of the substance. However, the species tested is relevant to the endpoint, the study report is well documented and its design appears to be in the spirit of the current guideline. The study is adequate for the purposes of hazard identification and classification.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Principles of method if other than guideline:
A preliminary range-finding test was performed to determine the approximate range in which the median lethal oral dose (LD50) fell. The subsequent main study involved testing of a larger number of animals to determine the LD50 value more precisely.
GLP compliance:
not specified
Remarks:
: older study, pre-dates GLP
Test type:
standard acute method
Limit test:
no
Species:
mouse
Strain:
CD-1
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS

- Weight at study initiation: 18 to 23 g.
- Fasting period before study: animals were fasted overnight before treatment.


Route of administration:
oral: gavage
Vehicle:
other: Aqueous methylcellulose 1%
Details on oral exposure:
VEHICLE
- Concentration in vehicle: 40% (w/v)
- Amount of vehicle (if gavage): 40 mL/kg (control group, vehicle only); 10 to 40 mL/kg (treatment groups).


MAXIMUM DOSE VOLUME APPLIED: 40 mL/kg.
Doses:
0.4, 1.0, 4.0, 16 g/kg. (range finding screen)
0, 4.0, 6.4, 10, 16 g/kg. (main study)
No. of animals per sex per dose:
2 (range finding screen)
5 (main study)
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: wieghts recorded weekly
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, other: macrosopic examination of target organs.
Statistics:
The LD50 and its 95% confidence limits were calculated by the method of Litchfield J.T. and Wilcoxon F. (1949) J. Pharmac. Exp. Ther, 96, 99-113.
Preliminary study:
The preliminary range finding tests indicated that the median lethal oral dose (LD50) was in the region of 4.0 to 16 g/kg.
Sex:
male/female
Dose descriptor:
LD50
Effect level:
14 500 mg/kg bw
95% CL:
>= 11.2 - <= 18.7
Mortality:
One male and one female mouse died at 10 g/kg; three male and three female mice died at 16 g/kg. Deaths occurred within three hours to 23 hours
after dosing.
Clinical signs:
Signs of reaction to treatment, observed shortly after dosing included piloerection in all treated animals, abnormal body carriage (hunched posture)
and ptosis in animals treated at 6.4 g/kg and above and lethargy decreased respiratory rate and abnormal gait (waddling) in animals treated at 10 and 16 g/kg.
These signs were accompanied by fine body tremors and pallor of the extremities amongst mice at 10 and 16 g/kg, by ataxia in one mouse at 10 g/kg and intwo mice at 16 g/kg and, by coma with recovery in two female mice at 16 g/kg.
Body weight:
Bodyweight gains in surviving mice were normal
Gross pathology:
In the mice which died during the observation period, autopsy revealed haemorrhage and congestion of the lungs and pallor of the liver, kidneys and
spleen.
Other findings:
- Other observations: Prior to death loss of righting reflex was observed in threee mice at 16 g/kg. Piloerection only was observed in the control mice.

Mortality data for groups of mice dosed orally with DI-TMP

Range Finding Screen

Dosage (g/kg)

Mortality ratio (No. of deaths / No. dosed)

Time of death after dosing (Hours)

Concentration %

Male

Female

Combined

0.4

10

0/2

0/2

0/4

-

1.0

10

0/2

0/2

0/4

-

4.0

40

0/2

0/2

0/4

-

16

40

1/2

2/2

3/4

<20

Mortality ratio and group mean bodyweight (g) of mice dosed orally with DI-TMP

Main study

Sex

Dosage (g/kg)

Bodyweight (g) at

Mortality ratio (No. of deaths / No. dosed)

Time of death after dosing (Hours)

dosing

1 week

2 weeks

Male

0

21

30

34

0/5

-

4.0

20

30

36

0/5

-

6.4

21

29

32

0/5

-

10

20

30

33

1/5

<4

16

22

31

36

3/5

<4

Female

0

20

25

27

0/5

-

4.0

19

25

26

0/5

-

6.4

19

25

27

0/5

-

10

21

26

28

1/5

<23

16

19

23

36

3/5

<4

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute median lethal oral dose (LD50) and its 95% confidence limits to mice of DI-TMP were calculated to be 14.5 (11.2 to 18.7) g/kg bodyweight.
Executive summary:

A study was performed by Huntingdon Research Centre, England on behalf of Perstorp Chemicals, Sweden to determine the acute oral toxicity to CD-1 mice of the test substance DI-TMP. No official Test Guidelines were cited, however the study design and species used were relevant and broadly in line with modern test guidelines. The LD50 in mice of the test substance was found to be 14.5 g/kg bodyweight (95% confidence limits 11.2 to 18.7 g/kg bodyweight).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
14 500 mg/kg bw
Quality of whole database:
A single mouse study is available; the study is relatively old and was not performed to any specific guideline but is considered to be adequate for the purposes of hazard identification and classification.

Acute toxicity: via inhalation route

Link to relevant study records
Reference
Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 September 2015 to 05 November 2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP and OECD guideline compliant study with no deviations
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Version / remarks:
2009
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Version / remarks:
2014
Deviations:
no
GLP compliance:
yes (incl. certificate)
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Envigo RMS (UK) Limited, Oxon, UK.
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: 200-350 g
- Housing: in groups of up to five by sex in solid-floor polypropylene cages with stainless steel lids, furnished with softwood flakes (Datesand Ltd., Cheshire, UK) and provided with environmental enrichment items: wooden chew blocks and cardboard “fun tunnels” (Datesand Ltd., Cheshire, UK)
- Diet (e.g. ad libitum): Rodent 2014C Teklad Global Certified Diet (Envigo RMS (UK) Limited, Oxon, UK) ad libitum
- Water (e.g. ad libitum): mains drinking water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25°C
- Humidity (%): 30-70%
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 hour cycle

IN-LIFE DATES: From: 13 October 2015 To: 05 November 2015
Route of administration:
inhalation: dust
Type of inhalation exposure:
nose only
Vehicle:
air
Details on inhalation exposure:
In order to facilitate aerosolisation and reduce particle size, the test item was ground using a Retsch Planetary Ball Mill (Retsch (UK) Ltd, Leeds, UK) prior to use. A dust atmosphere was produced from the test item using a SAG 410 Solid Aerosol Generator (TOPAS GmbH, Dresden, Germany) located adjacent to the exposure chamber. The SAG 410 was connected to a metered compressed air supply. Compressed air was supplied by means of an oil free compressor and passed through a water trap and respiratory quality filters before it was introduced to the SAG 410. The cylindrical exposure chamber had a volume of approximately 30 liters (dimensions: 28 cm diameter x 50 cm high). The concentration within the chamber was controlled by adjusting the test item feed rate from the SAG 410. The extract from the exposure chamber passed through a ‘scrubber’ trap and was connected with a high efficiency filter to a metered exhaust system. The chamber was maintained under negative pressure.

Three days prior to the day of exposure, each rat was acclimatized (for approximately 2 hours) to a tapered polycarbonate restraining tube. During the exposure period, each rat was individually held in a tapered, polycarbonate restraining tube fitted onto a single tier of the exposure chamber
and sealed by means of a rubber ‘O’ ring. Only the nose of each animal was exposed to the test atmosphere. Following an appropriate equilibration period a single group of ten rats (five males and five females) was exposed to an atmosphere of the test item for a period of four hours. A target
concentration of 5.0 mg/L was used for the exposure. As the mean achieved concentration was 103 % of target and no deaths occurred, no further levels were required.

The temperature and relative humidity inside the exposure chamber were measured by an electronic thermometer/humidity meter (Hanna Instruments Ltd, Beds., UK) located in a vacant port in the animals’ breathing zone of the chamber and recorded every thirty minutes throughout the four-hour exposure period. Oxygen levels within the exposure chamber were measured by an electronic oxygen analyzer (Servomex (UK) Ltd, Crowborough, East Sussex) located in a port in the animals breathing zone during the four-hour exposure period. The test atmosphere was generated to contain at least 19% oxygen.
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
5.15 (mg/L) achieved concentration
No. of animals per sex per dose:
5
Control animals:
no
Details on study design:
All animals were observed for clinical signs at hourly intervals during exposure, immediately on removal from the restraining tubes at the end of exposure, one hour aftre termination of exposure and subsequently once daily for fourteen days. Any evidence of overt toxicity was recorded at each observation. Individual body weights were recorded on arrival, prior to treatment on the day of exposure and on Days 1, 3, 7 and 14. At the end of the fourteen day observation period the animals were killed by intravenous overdose of sodium pentobarbitone. All animals were subjected to a full external and internal examination, and any macroscopic abnormalities were recorded. The respiratory tract was subjected to a detailed macroscopic examination for signs of irritancy or local toxicity.

Data evaluations included the relationship, if any, between the animals’ exposure to the test item and the incidence and severity of all abnormalities including behavioral and clinical observations, necropsy findings, body weight changes, mortality and any other toxicological effects. Using the mortality data obtained, an estimate of the acute inhalation median lethal concentration (LC50) of the test item was made.
Preliminary study:
Not applicable
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.15 mg/L air (analytical)
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: No mortality at the limit concentration
Mortality:
No mortalities occured.
Clinical signs:
other: Signs of hunched posture and pilo- erection are commonly seen in animals for short periods on removal from the chamber following 4-Hour inhalation studies. Wet fur is commonly recorded both during and for a short period after exposure. These observations
Body weight:
All animals exhibited body weight losses on the first day post-exposure. Body weight gains were noted in all animals during the remainder of the recovery period.
Gross pathology:
With the exception of one instance of dark patches on the lungs, no macropscopic abnormalities were detected amongst animals at necropsy.
Other findings:
No other findings reported.

Exposure Chamber Concentration

Atmosphere Concentration

Mean Achieved (mg/L)

Standard Deviation

Nominal (mg/L)

5.15

0.20

15.8

Particle Size Distribution

Mean Achieved Atmosphere Concentration (mg/L)

Mean Mass Median Aerodynamic Diameter (µm)

Inhalable Fraction (% <4 µm)

Geometric Standard Deviation

5.15

2.42

66.8

3.23

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
No deaths occurred in a group of ten rats exposed to a mean achieved atmosphere concentration of 5.15 mg/L for four hours. The acute 4 hr LC50 is therefore considered to be greater than 5.15 mg/L and classification is not required.
Executive summary:

The acute inhalation toxicity of di-TMP was investigated in 5 male and 5 female RccHAN:WIST rats, according to OECD 403 (2009). The rats were exposed nose-only to a dust atmosphere for four hours, followed by a 14-day observation period. The mean achieved atmosphere concentration was 5.15 mg/L (nominal 15.8 mg/L). The MMAD was determined to be 2.42 µm with a geometric standard deviation of 3.23, and the inhalable fraction (% <4 µm) was 66.8%. No deaths occurred. Common abnormalities noted during the study included decreased respiratory rate, increased respiratory rate, hunched posture, pilo-erection and wet fur. All animals recovered to appear normal on Day 2 post-exposure. All animals exhibited body weight losses on the first day post-exposure. All animals exhibited body weight gains during the remainder of the recovery period. No macroscopic abnormalities were detected at necropsy. No deaths occurred in a group of ten rats exposed to a mean achieved atmosphere concentration of 5.15 mg/L for four hours; the acute LC50 is therefore considered to be greater than 5.15 mg/L. Classification for acute inhalation toxicity according to Regulation (EC) No 1272/2008 is not required.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LC50
Value:
5 150 mg/m³
Quality of whole database:
A new guideline and GLP compliant study in the rat is available.

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Acute oral toxicity

The acute oral LD50 in mice of Di-TMP was found to be 14500 (11200 -18700 mg/kg bw).

Acute dermal toxicity

A study is not required; a waiver is proposed according to Column 2 of Annex VIII of the REACH Regulation. The acute toxicity of the substance has been investigated by the inhalation route. The substance is of inherently very low toxicity and low toxicity can also reliably be predicted for the dermal route of exposure.

Acute inhalation toxicity

A recent, guideline (OECD 403) and GLP compliant study was conducted in male and female rats (Griffiths, 2015). The rats were exposed nose-only to a dust atmosphere of Di-TMP for 4 hours and observed for 14 days. The mean achieved concentration was 5.15 mg/L Di-TMP, and 66.8% of particles were in the inhalable fraction (< 4 µm). No deaths occurred, and clinical observations were limited to common abnormalities associated with nose-only inhalation exposure and restraint, and all animals recovered by Day 2 post-exposure. The acute 4-hour LC50 of Di-TMP in the rat was considered to be greater than 5.15 mg/L.


Justification for selection of acute toxicity – oral endpoint
Single study available for this endpoint

Justification for selection of acute toxicity – inhalation endpoint
Modern guideline and GLP compliant study

Justification for classification or non-classification

The data indicate that Di-Trimethylolpropane is of very low acute toxicity by all routes. No classification according to Regulation (EC) No 1272/2008 is therefore proposed.