Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
no study available

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:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP conform study following OECD guidelines.
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.1300 (Acute inhalation toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS

Number of Animals: 10

Sex: 5 Males and 5 Females. The females assigned to test were nulliparous and non-pregnant.

Species/Strain: Rat/Sprague-Dawley derived, albino.

Age/Body weight: Young adult (11-12 weeks)/males 293-335 grams and females 226-234 grams at experimental start.

Source: Received from Harlan Laboratories, Inc. on March 21, 2012.

ENVIRONMENTAL CONDITIONS

Housing: The animals were singly housed in suspended stainless steel caging with mesh floors, which conform to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Litter paper was placed beneath the cage and was changed at least three times per week.

Animal Room Temperature and Relative Humidity Ranges: 21-23ºC and 42-57%, respectively.

Animal Room Air Changes/Hour: 13. Airflow measurements are evaluated regularly and the records are kept on file at Product Safety Labs.

Photoperiod: 12-hour light/dark cycle

Acclimation Period: 22 days

Food: Harlan Teklad Global 16% Protein Rodent Diet® #2016. The diet was available ad libitum, except during the exposure.

Water: Filtered tap water was supplied ad libitum by an automatic water dispensing system except during exposure.

Contaminants: There were no known contaminants reasonably expected to be found in the food or water at levels which would have interfered with the results of this study. Analyses of the food and water are conducted regularly and the records are kept on file at Product Safety Labs.

Route of administration:
inhalation: dust
Type of inhalation exposure:
nose only
Vehicle:
air
Details on inhalation exposure:
NOSE-ONLY EXPOSURE CHAMBER: A nose-only inhalation chamber with an internal volume of approximately 6.7 liters (Mini-Nose Only Inhalation Chamber, ADG Developments LTD) was used for exposure. Animals were individually housed in polycarbonate holding tubes which seal to the chamber with an “O” ring during exposure. The base unit terminates the chamber with a 0.5-inch diameter tube for discharged air.

AIR SUPPLY: Approximately 30.0 liters per minute (Lpm) of filtered air was supplied by an air compressor (Powerex Model: SES05) to the dust generator. An additional 6.0 Lpm of compressed mixing air, supplied by an air compressor (Powerex Model: SES05) which was introduced into the chamber to help uniformly distribute the test atmosphere by creating a vortex at the chamber inlet. Compressed airflow was measured with a Mass Flowmeter (Omega, Model #FMA-5613). Chamber airflow was monitored throughout the exposure period and recorded periodically. Total airflow was 36.0 Lpm. Based on the volume of the inhalation chamber, this airflow provided approximately 322 air changes per hour during the study.
.
AMBIENT CONDITIONS: The exposure tube temperature and relative humidity ranges during exposure were 20-21ºC and 15-16%, respectively. The room temperature and relative humidity ranges during exposure were 20-21ºC and 32-33%, respectively. In-chamber measurements and room conditions were measured with a Temperature-Humidity Monitor (Fisher Scientific, Model #11-661-18). Temperature and relative humidity values were recorded every 15 minutes for the first hour of exposure and every 30 minutes thereafter.

DUST GENERATION: The test substance was aerosolized using a modified Wright Dust Generator (Dayton, Model #4Z538A) driven by a variable speed motor D.C. speed control with 0-100 potentiometer. The test substance was packed into the dust container (Wright, Model DF183) and compressed to 1,000 lbs/in2 using a lab press (Carver, Model C). The container was then fitted with a stainless steel cutting head (Model DF194SS) and cutting blade (Model DF191SS). Compressed/mixing air was supplied to the dust generator at 30 psi. The aerosolized dust was then fed directly into the chamber through the dust outlet assembly

CHAMBER CONCENTRATION MEASUREMENTS: Gravimetric samples were withdrawn at six intervals from the breathing zone of the animals. Samples were collected using 37 mm glass fiber filters (GF/B Whatman) in a filter holder attached by ¼ inch Tygon tubing to a vacuum pump (Westech Vacuum Pump). Filter papers were weighed before and after collection to determine the mass collected. This value was divided by the total volume of air sampled to determine the chamber concentration. The collections were carried out for 1 minute at airflows of 4 Lpm. Sample airflows were measured using a Mass Flowmeter (Aalborg, Model #GFC-17).

PARTICLE SIZE DISTRIBUTION: An eight-stage ACFM Anderson Ambient Particle Sizing Sampler was used to assess the particle size distribution of the test atmosphere. Samples were withdrawn from the breathing zone of the animals at two intervals. The filter paper collection stages were weighed before and after sampling to determine the mass collected upon each stage. The aerodynamic mass median diameter and geometric standard deviation were determined graphically using two-cycle logarithmic probit axes.
- Particle size distribution: see table 1
- MMAD : 3.5 µm +- 0.08

EXPOSURE PERIOD: The animals were exposed to the test atmosphere for 4 hours and 1 minute. The exposure period was extended beyond 4 hours to allow the chamber to reach equilibrium (T99). The times for 90 and 99% equilibration of the chamber atmosphere were 0.4 and 0.9 minutes, respectively. At the end of the exposure period, the generation was terminated and the chamber was operated for a further 17 minutes with clean air. At the end of this period the animals were removed from the exposure tube. Prior to being returned to their cages, excess test substance was removed from the fur of each animal.

Analytical verification of test atmosphere concentrations:
yes
Concentrations:
see table 2
No. of animals per sex per dose:
5 male/ 5female
Details on study design:
Individual body weights of the animals were recorded prior to test substance exposure (initial) and on Days 1, 3, 7 and 14 (termination).

All animals were observed for mortality during the exposure period. The animals were examined for signs of gross toxicity, and behavioral changes upon removal from the exposure tube and at least once daily thereafter for 14 days. Observations included gross evaluation of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behavior pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhea, and coma.

All rats were euthanized via CO2 inhalation on Day 14. Gross necropsies were performed on all animals. Tissues and organs of the thoracic and abdominal cavities were examined.
Preliminary study:
not applicable
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.05 mg/L air
Based on:
test mat.
Exp. duration:
4 h
Mortality:
no mortalities
Clinical signs:
Following exposure, all animals exhibited abnormal respiration. However, the animals recovered from this symptom by Day 6 and appeared active and healthy for the remainder of the 14-day observation period.
Body weight:
Although all animals lost body weight by Day 1 and/or Day 3, all animals showed a continued weight gain thereafter through Day 14.
Gross pathology:
No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.
Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the conditions of this study, the single exposure acute inhalation LC50 of the test substance is greater than 5.05 mg/L in male and female rats. Based on the results of this study, Titanium Diboride has no labeling requirements for acute inhalation toxicity and is not classified.
Executive summary:

An acute inhalation toxicity test was conducted with rats to determine the potential for Titanium Diboride to produce toxicity from a 4-hour exposure via the inhalation (nose-only exposure) route. Under the conditions of this study, the single exposure acute inhalation LC50 of the test substance is greater than 5.05mg/L in male and female rats. Based on the results of this study, Titanium Diboride has no labeling requirements for acute inhalation toxicity and is not classified.

After establishing the desired generation procedures during pre-test trials, ten healthy rats (5/sex) were exposed to the test atmosphere for 4 hours. Chamber concentration and particle size distributions of the test substance were determined periodically during the exposure period. The animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for 14 days following exposure. Body weights were recorded prior to exposure and again on Days 1, 3, 7 and 14 (termination). Necropsies were performed on all animals at terminal sacrifice.

The gravimetric chamber concentration was 5.05mg/L. Based on graphic analysis of the particle size distribution as measured with an ACFM Andersen Ambient Particle Sizing Sampler, the mass median aerodynamic diameter was estimated to be 3.5.

All animals survived exposure to the test atmosphere. Following exposure, all animals exhibited abnormal respiration. However, the animals recovered from this symptom by Day 6 and appeared active and healthy for the remainder of the 14-day observation period. Although all animals lost body weight by Day 1 and/or Day 3, all animals showed a continued weight gain thereafter through Day 14. No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period. 

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed

Acute toxicity: via dermal route

Link to relevant study records
Reference
Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP conform study following OECD guidelines.
Qualifier:
according to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.1200 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
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:
Species/strain: healthy rats, WISTAR rats Crl: WI(Han) (full barrier)

Source: Charles River, 97633 Sulzfeld, Germany

Sex: male and female; The female animals were non-pregnant and nulliparous.

Number of animals: 5 male and 5 female

Age at the beginning of the study: males: 9 weeks old, females: 16 weeks old

Body weight on the day of administration: males: 245 – 253 g; females: 213 – 227 g.

The animals were derived from a controlled full-barrier maintained breeding system (SPF). According to Art. 9.2, No. 7 of the German Act on Animal Welfare [9] the animals were bred for experimental purposes.

Housing and Feeding Conditions

- Full barrier in an air-conditioned room
- Temperature: 22 +- 3 °C
- Relative humidity: 55 +- 10%
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: 10 x / hour
- Free access to Altromin 1324 maintenance diet for rats and mice (lot no. 0715)
- Free access to tap water, sulphur acidified to a pH value of approximately 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)
- The animals were kept individually in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding (lot no. 261111)
- Certificates of food, water and bedding are filed at BSL BIOSERVICE
- Adequate acclimatisation period (at least five days) under laboratory conditions

Type of coverage:
semiocclusive
Vehicle:
water
Details on dermal exposure:
Application
The test item was applied at a single dose, uniformly over an area which was approximately 10% of the total body surface.
The test item was held in contact with the skin by a dressing throughout a 24-hour period. The dressing consisted of a gauze-dressing and non-irritating tape and was fixed with an additional dressing in a suitable manner.


Exposure Period
The test item was held in contact with the skin throughout a 24-hour period. At the end of the exposure period the residual test item was removed using aqua ad injectionem (see Vehicle)
.

Vehicle
Aqua ad injectionem (Diprom, lot no. 10952-1, expiry date: 09/2013)
Duration of exposure:
24 h
Doses:
The test item was applied at a single dose of 2000 mg/kg body weight to each animal.
No. of animals per sex per dose:
5 male and 5 female
Control animals:
not required
Details on study design:
Observation Period
The surviving animals /All animals were observed for 14 days after dosing.

Primary Skin Irritation
Signs of erythema and oedema were assessed using the scoring system laid down in OECD Guideline 404.

Weight Assessment
The animals were weighed on day 1 (prior to the application) and on days 8 and 15.

Clinical Examination
A careful clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose). As soon as symptoms were noticed they were recorded. Thereafter, the animals were observed for clinical signs once daily until the end of the observation period. All abnormalities were recorded.
Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined. Attention was directed to observations of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.

Pathology
At the end of the observation period the surviving animals were sacrificed with an overdosage of pentobarbital injected intraperitoneally (Narcoren®, Merial; lot no. 218121; expiry date: 12/2014) at the dosage of approximately 8 mL/kg bw.
All animals were subjected to gross necropsy. All gross pathological changes were recorded and in case of findings the tissues were preserved for a possible histopathological evaluation. The preserved tissues of which no histopathological evaluation was made will be discarded 3 months after the release of the final report unless otherwise agreed upon with the sponsor.

Evaluation of Results
Individual reactions of each animal were recorded at each time of observation.
Toxic response data were recorded by sex and dose level.
Nature, severity and duration of clinical observations were described.
The body weight changes were summarised in a tabular form.
Necropsy findings were described.



Statistics:
Not applicable, no clinical signs of irritation or mortality.
Preliminary study:
not applicable
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
no deaths
Clinical signs:
no signs of systemic toxicity, dermal irritation,
Body weight:
A slight weight loss was recorded for 4 out of 5 female animals during the first week, but 4 out of 5 female animals showed weight gain during the second week. 1 out of 5 female animals showed weight loss during the second week. The effects on weight development might be secondary to the dressing, and toxicological relevance of this finding cannot clearly be concluded.

The male animals showed weight gain during the first and the second week of the observation.
Gross pathology:
With the exception of acute injection of blood vessels in the abdominal region, which is due to the euthanasia injection, no specific gross pathological changes were recorded for any animal
Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the conditions of the present study, single dermal application of the test item Titanium Diboride to rats up to 2000 mg/kg body weight was associated with no mortality and neither signs of toxicity nor signs of irritation.

The dermal LD50 was determined to be > 2000 mg Titanium Diboride / kg body weight.

In conformity with the criteria given in Annex VI to Commission Directive 2001/59/EC [6] the test item Titanium Diboride has no obligatory labelling requirement for percutaneous toxicity.

According to Annex I of Regulation (EC) 1272/2008 [7] the test item Titanium Diboride has no obligatory labelling requirement for percutaneous toxicity and is unclassified.

According to GHS (Globally Harmonized Classification System) [8] the test item Titanium Diboride has no obligatory labelling requirement for percutaneous toxicity and is not classified.
Executive summary:

On the basis of the test results given below and in conformity with the criteria given in Annex VI to Commission Directive 2001/59/EC, the substance should be not classified.

On the basis of the test results given below and in conformity with the criteria given in Annex I of Regulation (EC) 1272/2008, the substance should be not classified.

On the basis of the test results given below and in conformity with the criteria given in GHS (Globally Harmonized System of Classification and Labelling of Chemicals), the substance should be not classified.

LD50:             > 2000 mg/kg bw

Species/strain:                                         WISTAR Crl: WI(Han) rats

Vehicle (moistening):                               aqua ad injectionem

Number of animals:                                  5 male and 5 female

Duration of exposure:                             24 hours

Method:                                                  OECD 402; EC 440/2008, Method B.3; OPPTS 870.1200


 

Table1:  Results per Step

Sex

Dose
(mg/kg bw)

Number
of Animals

Number
of Intercurrent Deaths

male

2000

5

0

female

2000

5

0

Signs of toxicity related to dose level used, time of onset and duration:

No treatment-related effects were observed.

Effect on organs (related to dose level):

No treatment-related effects were observed.

Signs of irritation:

No erythema or oedema was observed.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed

Additional information

Justification for classification or non-classification