Magnesium potassium titanium oxide

Endpoint summary

Description of key information

No adverse effects at the concentration limit of 1000 mg/kg bw/day in the sub-acute repeated dose toxicity study (EC B.7/OECD 407) with rats were noted. NOAEL is >= 1000 mg/kg bw/day.  In a 90-day inhalation toxicity study according to OECD/EPA test guidelines, no adverse effects were noted at the highest dose tested, 50 mg/m3. Therefore the NOAEL is >= 50 mg/m3.

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

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 November-20 December 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study has been performed according to OECD and EC guidelines and according to GLP principles.

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Version / remarks:

(1996)

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Version / remarks:

(1995)

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Outbred, SPF quality. Source: Charles River Deutschland, Sulzfeld, Germany.
Age of the animals at the start of reatment: 6 weeks.
Identification by earmark and tattoo.
A health inspection was performed prior to commencement of treatment to ensure that the animals were in a good state of health.

Route of administration:

oral: gavage

Vehicle:

other: 1% Aq. Carboxymethyl cellulose

Details on oral exposure:

A stainless steel stomach tube was used. Dose volume: 5 mL/kg body weight. Actual dose volumes were calculated weekly according to the latest body weight.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Quadruple samples of formulations (5.00 ml) were taken on 11 December 2000.
Groups 1 and 3 (0 and 150 mg/kg bw/day): samples taken from the middle (accuracy)
Groups 2 and 4 (50 and 1000 mg/kg bw/day): samples taken from top, middle and bottom (accuracy and homogeneity)

The samples were stored at room temperature in labelled pots until analysis.

Analysis of the samples was performed under the responsibility of Solvias AG, Elemental and Microanalytical Services, Basel, Switzerland

Duration of treatment / exposure:

Test duration: 28 days

Frequency of treatment:

Dosing regime: 7 days/week, approximately the same time each day with a maximum of 4 hours difference between the earliest and latest dose. Animals were dosed up to the day prior to necropsy.

Remarks:

Doses / Concentrations:
0, 50, 150 and 1000 mg/kg bw/day
Basis:
nominal in diet

No. of animals per sex per dose:

One control group and three treated groups were tested, each consisting of 5 males and 5 females.

Control animals:

yes

Details on study design:

The dose levels were selected on the basis of a 5-day dose range finding study.
A controlled environment was maintained in the room with optimal conditions considered as being approximately 15 air changes per hour, a temperature of 21±3C, a relative humidity of 30-70% and 12 hours artificial fluorescent light and 12 hours dark per day.

Group housing of 5 animals per sex per cage in stainless steel suspended cages with wire mesh floors (55 x 34 x 21.5 cm height). Acclimatisation period was at least 5 days before start of treatment under laboratory conditions. During activity monitoring, animals were individually housed overnight in Macrolon plastic cages (type III, height 15 cm.) with sterilised sawdust (SAWI, Jelu Werk, Rosenberg, Germany) provided as bedding. Results of bedding analyses for contaminants are examined and archived.

Free access to standard pelleted laboratory animal diet and to tap water.

Analysis of bedding, diet and water did not reveal any findings that were considered to have affected study integrity.

Observations and examinations performed and frequency:

The following parameters were evaluated: clinical signs daily; functional observation tests; body weight and food consumption weekly; clinical pathology and macroscopy at termination; organ weights and histopathology on a selection of tissues.

MORTALITY/Viability: twice daily

CLINICAL SIGNS: once daily,
detailed clinical observations were made in all animals. Once prior to start of treatment and on days 8, 15, 22 and 28, this was also performed outside the home cage in a standard arena. The symptoms were graded according to fixed scales and the time of onset, degree and duration were recorded:

FUNCTIONAL OBSERVATIONS:
During week 4 of treatment, the following tests were performed on all animals:
-hearing ability, pupillary reflex, static righting reflex and grip strength (Score 0 = normal/present, score 1 = abnormal/absent).
-motor activity test (recording period: 12 hours during overnight for individual animals, using a computerised monitoring system).

BODY WEIGHT: weekly
On days 1, 8, 15, 22 and 28.

FOOD CONSUMPTION: Weekly

WATER CONSUMPTION:
Subjective appraisal was maintained during the study, but no quantitative investigation introduced as no effect was suspected.

CLINICAL LABORATORY INVESTIGATIONS:
Blood samples were collected under iso-flurane anaesthesia immediately prior to scheduled post mortem examination, between 7.30 and 9.30 a.m. The animals were fasted overnight (with a maximum of 20 hours) before blood sampling, but water was provided. Blood samples were drawn from the retro-orbital sinus of all rats/sex/group and collected into tubes prepared with EDTA for haematological parameters (0.25 ml), with citrate for clotting tests (1.0 ml) and Li-heparin treated tubes for clinical biochemistry parameters (1.0 ml).

Sacrifice and pathology:

All animals surviving to the end of the observation period were deeply anaesthetised using iso-flurane and subsequently exsanguinated. All animals assigned to the study were necropsied and descriptions of all macroscopic abnormalities recorded. Samples of the following tissues and organs were collected from all animals at necropsy and fixed in a 4% formaldehyde solution:
Adrenal glands, Aorta, Brain, Caecum, (Cervix), (Clitoral gland), Colon, Duodenum, Epididymides, (Eyes with optic nerve and Harderian gland), (Female mammary gland area), (Femur including joint), Heart, Ileum, Jejunum, Kidneys, (Larynx), (Lacrimal gland, exorbital), Liver, Lung, infused with formalin, Lymph nodes - mandibular, mesenteric, (Nasopharynx), Oesophagus, Ovaries, Pancreas, Peyer's patches (jejunum, ileum) if detectable, Pituitary gland, (Preputial gland), Prostate gland, Rectum, (Salivary glands - mandibular, sublingual), Sciatic nerve, (Seminal vesicles), (Skeletal muscle), (Skin), Spinal cord -cervical, midthoracic, lumbar
Spleen, Sternum with bone marrow, Stomach, Testes, Thymus, Thyroid including parathyroid, (Tongue), Trachea, Urinary bladder, Uterus, (Vagina) and aAll gross lesions. Identification marks: not processed.

All organ and tissue samples, as defined below, were processed, embedded and cut at a thickness of 2-4 micrometers and stained with haematoxylin and eosin. The following slides were examined by a pathologist:
-all tissues and organs collected at the scheduled sacrifice from all animals of the control and the highest dose group;
-all gross lesions of all animals.
All abnormalities were described and included in the report. Tissues mentioned within brackets were not examined as there were no signs of toxicity or target organ involvement

Other examinations:

The following organ weights (and terminal body weight) were recorded from the surviving animals on the scheduled day of necropsy: adrenal glands, brain, Epididymides, Heart, Kidneys, Liver, Spleen, Testes and Thymus.

Blood samples were collected under iso-flurane anaesthesia immediately prior to scheduledpost mortemexamination, between 7.30 andThe animals were fasted overnight (with a maximum of 20 hours) before blood sampling, but water was provided. Blood samples were drawn from the retro-orbital sinus of all rats/sex/group and collected into tubes prepared with EDTA for haematological parameters (0.25 ml), with citrate for clotting tests (1.0 ml) and Li-heparin treated tubes for clinical biochemistry parameters (1.0 ml).

Statistics:

The following statistical methods were used to analyse the data:

- If the variables could be assumed to follow a normal distribution, the Dunnett-test (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (many-to-one rank test) was applied when the data could not be assumed to follow a normal distribution.
- The exact Fisher-test was applied to frequency data.

All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of
significance. Group means were calculated for continuous data and medians were calculated for
discrete data (scores) in the summary tables. No statistical analysis was performed on motor activity data. Test statistics were calculated on the basis of exact values for means and pooled variances. Individual values, means and standard deviations may have been rounded off before printing. Therefore, two groups may display the same printed means for a given parameter, yet display different test statistics values.

References:
- C.W. Dunnett, Multiple Comparison Procedure for Comparing Several Treatments with a Control, J. Amer. Stat. Assoc. 50, 1096-1121 (1955).
- R.G. Miller, Simultaneous Statistical Inference, Springer Verlag, New York (1981).
- R.A. Fisher, Statistical Methods for Research Workers, Oliver and Boyd, Edinburgh (1950).

Clinical signs:

no effects observed

Description (incidence and severity):

no mortality

Mortality:

no mortality observed

Description (incidence):

no mortality

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

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

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Details on results:

MORTALITY:
No mortality occurred during the study period.

CLINICAL SIGNS:
No treatment-related abnormalities were found.
Hunched posture was shown by one high dose male in weeks 3 and 4. This male also showed slightly reduced body weight gain, and reduced weight of the thymus and spleen. The other animals within this group were without such findings. Therefore, this sign was considered to be related to a general deteriorated health status and not to be a sign of toxicity. Scabs, as shown by one high dose female, are commonly noted in rats of this age and strain and housed and treated under the conditions in this study and considered of no toxicological significance. Other animals were without clinical signs.

NEUROBEHAVIOUR:
No changes were observed in hearing ability, pupillary reflex, static righting reflex and grip strength in the animals treated with TERRACESS P, when compared to control animals. The variation in motor activity did not indicate a relation with treatment.
Increased motor activity as recorded by the high sensors was noted for one low dose group male. Low sensor readings were comparable to control values and no dose-related response was obtained. Motor activity of one high dose male as measured by the low sensors was slightly increased, but values of the other animals within this group were largely comparable to controls. Therefore, these changes were considered to be of no toxicological significance.

BODY WEIGHTS and FOOD CONSUMPTION:
No treatment related effects.
Body weights and body weight gain among group 3 and 4 males were slightly reduced in week 4. Among group 4 males this was largely due to a reduced weight gain of one animal. On exclusion of the value of this animal no dose-related decrease in body weights in obtained. Moreover, no effects on food consumption were noted. Therefore, the slightly decreased body weights of group 3 males in week 4 were considered to have occurred by chance. Also, the statistically significant decreased body weight gain of group 3 females in week 2 was considered to be of no toxicological relevance since group 4 values in week 2 were comparable to controls.

HAEMATOLOGY:
No treatment-related effects were found.
A (slightly) low platelet value was measured for two group 4 males, one group 2 female and one group 3 female. No microscopic evidence was obtained to support this finding. Values of other animals within the same group were comparable to control values. Mean corpuscular haemoglobin concentration showed a decrease among group 3 females. Since control values were slightly high when compared to historical data and a dose-response relationship was absent, this change was considered to be of no toxicological significance.

CLINICAL BIOCHEMISTRY:
No treatment-related effects were found.
A slightly high aspartate aminotransferase activity value was obtained for one animal (high dose male) and a high urea value was measured for one high dose female. There were no microscopic correlates and values of the other animals within the same group were comparable to controls. Statistically significant decreases of sodium and calcium values among group 3 and/or 4 males occurred in the absence of a clear dose-response relationship and all individual values were within the range of historical control data. Therefore, these changes were considered to be of no toxicological significance.

MACROSCOPIC EXAMINATION:
No treatment-related effects were found.
Incidental findings among control and/or treated animals included pelvic dilation of the kidneys, a reduced size of the thymus, an accesory lobe on the liver and scab formation on the skin. These findings are occasionally seen among rats used in these types of studies and were considered changes of no toxicological significance.

ORGAN WEIGHTS:
No treatment-related effects were found.
The slightly low terminal body weights of group 4 males were largely due to one animal. On exclusion of the value of this animal, no dose related decrease of terminal body weights was obtained. Decreased (relative) spleen and liver weights among group 2 females occurred in the absence of a dose related response. Therefore, these changes were considered not to represent a sign of toxicity.

MICROSCOPIC EXAMINATION:
No treatment-related effects were found.
All microscopic findings were within the range of background pathology encountered in Wistar rats of this age and strain and occurred at similar incidences and severity in both control and treated rats.

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No effects at highest dose tested / original NCD unit is mg/kg/day.

Critical effects observed:

not specified

Test substance formulations in 1% aqueous carboxymethyl cellulose formed a homogeneous suspension at the concentrations tested. Values of one group 3 sample and one group 4 sample slightly exceeded the acceptable range of 100±10% of nominal. However, since the other values were within this range and the homogeneity was acceptable, it was concluded that accuracy measurements represented an acceptable level for formulations of this type. A minimal amount of titanium was found in the control group vehicle. There were no indications that this caused any relevant effects in the control group animals. Therefore, this was considered not to be of any influence on the study integrity not the outcome.

Conclusions:

Terracess P is not classified as toxic (NOAEL: 1000 mg/kg/day)

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The study has a Klimisch score of 1.

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 16, 2006 - June 28, 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Performed according to EPA and OECD test guidelines and according to GLP.

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3465 (90-Day Inhalation Toxicity)

GLP compliance:

yes

Species:

rat

Strain:

other: Crl:CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Received from Charles River Laboratories, Inc., Raleigh, North Carolina.
- Age at study initiation: approx. 5 weeks
- Weight at study initiation: males, 141-195 grams; females, 126-175 grams.
- Fasting period before study:
- Housing: Stainless steel, wire-mesh cages suspended above cage boards. During quarantine, pretest, exposure and recovery phases, animals were housed singly.
- Diet (e.g. ad libitum): Except during exposures, PMI® Nutrition International, LLC Certified Rodent LabDiet® 5002
and tap water were available ad libitum. During the urine collection period, animals were fasted
overnight for 12 to 20 hours after approximately one to 3 hours of access to food following
exposure; water, however, was available ad libitum.
- Water (e.g. ad libitum):
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3ºC
- Humidity (%): 50 ± 20%.
- Air changes (per hr): 10/hr
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Remarks on MMAD:

MMAD / GSD: A sample to determine particle size distribution (mass median aerodynamic diameter and percent particles less than 1, 3, and 10 μm diameter) was taken 4 times per test level over the course of the daily exposure period. The MMAD of the aerosols ranged from 4.1 to 4.8 μm. About 20% of particle mass was less than 3 μm.

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
Chamber atmospheres were generated by suspension of the substance in air with a FLuid Energy Processing model 00 Jet-O-Mizer jetmill. The test substance was metered into the jetmill with a Schenck Accurate model 102M bin feeder. High-pressure air, metered into the Jet-OMizer by a distribution manifold, carried the resulting atmosphere into the exposure chamber. Dilution air, delivered with a rotometer, was added to the chambers to achieve the desired concentration. Chamber concentrations of test substance were also controlled by varying the feed rate or airflow to the atmosphere generator. Custom-made timer/controllers were used in conjunction with the bin feeder to achieve finer control of the 2 and 10 mg/m³ chambers. Air was delivered to the control chamber using the same type of Jet-O-Mizer/rotometer system as that used in the test chambers. Test atmospheres were exhausted through a high-capacity particle filter prior to discharge into the fume hood. The control chamber atmosphere was exhausted through an MSA charcoal/HEPA filter cartridge prior to discharge into the fume hood.
All exposure chambers were constructed of stainless steel and glass (NYU style) with a nominal internal volume of 350 L. A baffle inside the chamber promoted uniform chamber distribution of the test atmosphere. During exposure, animals were individually placed in stainless steel wire mesh cages and exposed, whole-body, inside the exposure chamber. The chamber volume was chosen so that the total body volume of the test animals did not exceed 5% of the chamber volume.

TEST ATMOSPHERE
- Brief description of analytical method used:
- Samples taken from breathing zone: yes/no

VEHICLE (if applicable)
- Justification for use and choice of vehicle:
- Composition of vehicle:
- Type and concentration of dispersant aid (if powder):
- Concentration of test material in vehicle:
- Lot/batch no. of vehicle (if required):
- Purity of vehicle:

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

During each exposure, the atmospheric concentration of the test substance was determined by gravimetric analysis at approximately hourly intervals in the test chambers. Known volumes of chamber atmosphere were drawn from the sampling port through a 25 mm filter cassette containing a pre-weighed glass fiber (Type A/E) filter. The filters were weighed on a Cahn model C-33 Microbalance®. The atmospheric concentration of the test substance was calculated from the difference between the pre- and post-sampling filter weights divided by the volume of chamber atmosphere sampled. The control chamber was not monitored for the test substance. A Microdust Pro dust analyzer was used during the study as an aid in control of atmospheric dust concentrations; however, these readings were not recorded.

Duration of treatment / exposure:

90-day, 67 exposures

Frequency of treatment:

6 h/d, 5d/w

Remarks:

Doses / Concentrations:
2.0, 10, 50 mg/m3
Basis:
analytical conc.

No. of animals per sex per dose:

20 males, 15 females

Control animals:

other: air only

Details on study design:

- Dose selection rationale: Based on the acute inhalation toxicity study and a 2 week inhalation study, the concentrations were chosen.
- Rationale for animal assignment (if not random): Rats of each sex were selected for use on study based on adequate body weight gain and freedom from any ophthalmology abnormalities or clinical signs of disease or injury. They were distributed by computerized, stratified randomization into study groups as designated in the Study Design, so that there were no statistically significant differences among group body weight means within a sex. At the start of the study, the weight variation of selected rats did not exceed ± 20% of the mean weight for each sex. The first 10 male and 10 female rats in each group were designated for sacrifice at the end of the exposure period. After an approximately one-month recovery period, 5 male rats per group were sacrificed. The remaining rats were sacrificed at the end of the approximately 3-month recovery period.
- Rationale for selecting satellite groups:
- Post-exposure recovery period in satellite groups: Two recovery periods of approximately one and three months duration were in place. During the recovery periods, exposures were not conducted: however, in-life observations and measurements (clinical observations and body weights) were continued. One month recovery group: 5 male rats/dose. Three month recovery group: remaining male and female rats, approx 4-5 rats/sex/dose. Since the substance related effects were observed only in the respiratory tract of the main study, microscopic evaluation of the three month recovery group was limited to tissues of the respiratory tract and gross lesions.
- Section schedule rationale (if not random):

Positive control:

Not relevant.

Observations and examinations performed and frequency:

An ophthalmology evaluation was conducted prior to the initiation of exposures and near the end of the exposure period.
Body weights and food consumption were determined on Day 0 and weekly thereafter.
Clinical observations were evaluated daily following exposures.
Detailed clinical observations were determined on Day 0 and weekly thereafter.

Sacrifice and pathology:

On the day following the last exposure, blood and urine samples were collected for clinical pathology analyses from 10 rats per sex per group, and these rats were sacrificed for anatomic pathology examination. After the conclusion of the exposure phase there were 2 recovery periods of approximately 1 and 3 months. At the one month recovery, 5 male rats per group were sacrificed and given anatomic pathology examinations; the remaining male and female rats were sacrificed approximately 3 months after exposure and also given anatomic pathology examinations. These included gross observations, organ weights and lung titanium analysis.

Other examinations:

Near the end of the exposure period, a functional observational battery and motor activity were conducted. Post necropsy, lung titanium analyses were conducted (ICPS) at 3 times during this study in groups of 5 male rats per group per time period.

Statistics:

Significance was judged at p < 0.05. Separate analyses were performed on the data collected for each sex.
Method of Statistical Analysis:
Exposure Concentration Data, Environmental Data, Lung Titanium Analysis: Descriptive statistics (e.g., mean, standard deviation).
Body Weight, Body Weight Gain, Food Consumption, Food Efficiency, Clinical Pathology, Organ Weight: Levene’s test for homogeneity and Shapiro-Wilk test for normality in the preliminary test. One-way analysis of variance followed with Dunnett's test if preliminary test is not significant. Kruskal-Wallis test followed with Dunn's test if preliminary test is significan.t
Motor Activity, Grip Strength: Levene’s test for homogeneity and Shapiro-Wilk test for normality in preliminary test. Repeated measures analysis of variance followed with Linear contrasts if preliminary test is not significant. Sequential application of the Jonckheere-Terpstra trend test is preliminary test is significant.
Incidence of FOB, Descriptive Parameters: Cochran-Armitage test for trend.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Details on results:

Prior to the initiation of the range finder, the concentration of Terracess PS at 9 different points was found to be within 10% of the mean concentration. This was considered to be sufficient indication of homogeneity of the test substance in the chamber.
The mean, gravimetrically determined, aerosol concentrations for the exposures were 2.0, 10, and 50 mg/m³. The mass median aerodynamic equivalent diameter (MADD) of the Terracess PS dust measured in the test atmospheres ranged from 4.1 to 4.8 μm. Geometric standard deviations
ranged from 1.2 to 1.8. About 20% of the particle mass was less than 3 μm.

BODY WEIGHTS AND BODY WEIGHT GAINS:
No substance related effects observed.

FOOD CONSUMPTION AND FOOD EFFICIENCY:
No substance related effects were observed.

CLINICAL OBSERVATIONS:
The only clinical observation of note was hair loss found sporadically in all groups. This is a common finding in inhalation studies in rats, and thus not considered to be due to the substance.

OPHTHALMOLOGY:
The ophthalmology exam conducted near the end of the exposure phase of the study showed focal retinal degeneration in 2 male rats, one each in the 10 and 50 mg/m³ groups. This is a common finding in rats and was not considered to be substance related.

NEUROLOGICAL BEHAVIOUR:
No substance related effects were observed on forlimb grip strength, hindlimb grip strength, open field observations, and motor activity.
Males in the 2 mg/m³ group had significantly higher forelimb grip strength compared to the control value. However, forelimb grip strength values for males in the 10 and 50 mg/m³ groups were similar to control; and therefore, the significantly higher value for the 2 mg/m³ males was not substance related. Males in the 2 mg/m³ group had significantly lower mean total number of movements. However, the total number of movements for the 10 and 50 mg/m³ were similar to the control value; and therefore, the significantly higher value for the 2 mg/m³ males was not substance related.

HAEMATOLOGY:
No treatment related or adverse changes in hematology parameters were present.
White blood cell, neturophil and lymphocyte counts were decreased in males exposed to all concentration groups, although all treated groups had similar means and individual counts. The apparent decrease in cell counts, resulted from increased white blood cell counts in three control animals. Excluding these three animals, resulted in comparable results between control and treated groups. In addition, no effects were found in females, no microscopic changes, thus effect was unrelated to treatement and non-adverse. Red cell distribution width was minimally decreased in males in the high dose group. No associated changes were present in red blood cell mass parameters or microscopic morphology, and thus not considered related to treatement and non-adverse.

CLINICAL CHEMISTRY:
No treatment related chagnes in clinical chemistry parameters.
The alkaline phosphatase activity was mnimally but statistically significant increased in females in the high dose group, due to the narrow range of activities. In addition, no anatomic pathology correlates to this change, and no changes in males. Therefore not considered related to treatement.
Chloride was minimally increase in males in the low dose group, however no dose related pattern and thus not considered treatement related.

URINALYSIS:
No treatment related effects.

MORTALITY:
Two deaths were interpreted to be incidental and not related to exposure. One male rat was accidentally killed during blood collection due to an anesthetic overdose, no gross or microscopic effects found. One female was euthanized following the accidental fracture of its nose.

ORGAN WEIGHTS:
No substance related effects on organ weights.
In females exposed to the highest concentration (50 mg/m³), there were small, statistically significant, decreases in mean absolute liver (11%) and heart (10%) weights, as compared to control values. These decreases were associated with a slight decrease (5%) in mean absolute final body weight, mean relative (% body weight) liver and heart weights were not statistically decreased, there were no organ weight effects in male rats, and there were no gross or microscopic test substance-related effects in the livers and hearts of either males or females.

GROSS PATHOLOGY:
No substance related effects. All gross observations recorded in this study, at all intervals, were consistent with normal background lesions in rats of this age and strain.

MICROSCOPIC FINDINGS:
There was no evidence of increased macrophage numbers, inflammation, or fibrosis. Rats allowed to recover for approximately 30 (males only) and 90 days demonstrated migration of pulmonary macrophages into aggregates and gradual clearance of test substance. The microscopic findings were consistent with exposure to a non-pathogenic nuisance dust.
There were no adverse test substance-related microscopic effects observed in the respiratory tract. Non-adverse accumulation of test substance within macrophages was observed in respiratory tract macrophages. Test substance related findings were not observed within any non-respiratory tract tissues. Microscopic examination of males and females following the 90-day exposure demonstrated no differences between the sexes.
The incidence and severity of particulate-laden macrophages within lymphoid tissue also appeared to be similar in the rats following either the 90-day exposure or the 30-day or 90-day recovery period.

Dose descriptor:

NOAEL

Effect level:

>= 50 mg/m³ air

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects at highest dose tested; only non-adverse respiratory tract effects at all exposure concentrations.

Critical effects observed:

not specified

In rats exposed to dust of the substance, lung titanium concentrations at the end the exposure period were roughly proportional to the exposure concentrations. There were no significant background titanium levels found in the control group. The clearance half-times for Terracess PS were estimated to be approximately 2 ½ months for the 2 and 10 mg/m³ groups and approximately 4 months for the 50 mg/m³ group.

Conclusions:

Under the conditions of this study, a 90-day whole body aerosol inhalation study, the no-effect level (NOEL)a for rats exposed to Terracess PS
for approximately 90 days was 50 mg/m³ based on the finding of only non-adverse respiratory tract effects at all exposure concentrations.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

50 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

The study has a Klimisch score of 1.

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In a subacute 28 -day repeated dose toxicity study, according to OECD 407 and EC B.7 test guidelines, four groups of 5 female and 5 male rats were exposed to Terracess P via oral gavage to 0, 50, 150 and 1000 mg/kg bw/day. Formulation analysis showed that the formulations were prepared accurately and homogenously.

No substance related changes in mortality, clinical appearance, or alterations at functional observations, body weight, food consumption, haematology and clinical chemistry parameters, and on organ weights, macroscopic and microscopic examinations were observed. Therefore, a NOAEL of >=1000 mg/kg bw/day was established.

In a 90 -day inhalation study performed according to OECD and EPA test guidelines, male and female rats were exposed to 0, 2.0, 10 and 50 mg/m3. There were no test-substance related adverse effects on mortality, body weights, clinical signs, neurobehavioral parameters, or food consumption during the study. Clinical pathology evaluations showed no test substance related effects in hematology, coagulation, serum chemistry, or urine parameters as a result of exposure to Terracess P dust. At each sacrifice period, sections of the lungs from 5 male rats per group were collected for titanium content to determine lung deposition and clearance of the test substance. Based on this information, the clearance half-times for Terracess P were estimated to be approximately 2 ½ months for the 2 and 10 mg/m³ groups and approximately 4 months for the 50 mg/m³ group. The clearance rate is somewhat faster than other low solubility, low toxicity dusts like titanium dioxide. There were no test substance-related organ-weight effects observed in the tested animals in this study. Histologic evaluation showed an exposure-related uptake of aerosol particulates by the resident pulmonary alveolar macrophages within the lung. There was no evidence of increased macrophage numbers, inflammation, or fibrosis. Rats allowed to recover for approximately one and 3 months showed migration of pulmonary macrophages into aggregates and gradual clearance of Terracess P. The microscopic findings were consistent with exposure to a nonpathogenic, nuisance dust. Under the conditions of this study, the NOAEL for rats exposed to Terracess P for approximately 90 days was >= 50 mg/m³ based on the finding of only non-adverse respiratory tract effects at all exposure concentrations.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
One key study available.

Justification for classification or non-classification

Based on the available studies, Terracess P does not have to be classified for repeated dose toxicity according to Directive 67/548/EEC and CLP Regulation EC (No.) 1272/2008.