Triiron bis(orthophosphate)

Endpoint summary

Description of key information

Acute oral toxicity: LD50 (female rats) > 2000 mg/kg bw (OECD 423; GLP)

Acute inhalation toxicity: LC50 (male and female rats) > 2.76 mg/L (actual concentration; maximum attainable concentration) (OECD 436; GLP)

Acute dermal toxicity: data waiving

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:

2016-01-20 to 2016-02-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

2001-12-17

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Germany GmbH, Sulzfeld, Germany
- Age: 8 - 12 weeks
- Weight: 205.9 to 276.7 g
- Fasting period before study: no diet overnight prior to application and 3 hours after application
- Housing: single-caged
- Diet (ad libitum, except for fasting period as described above): conventional laboratory diet (pellets, ssniff Spezialdiäten GmbH, Soest, Germany)
- Water (ad libitum): tap water (drinking quality)
- Acclimation period: at least 5 days prior to dosing

ENVIRONMENTAL CONDITIONS
- Temperature: 19 - 25 °C
- Relative humidity: 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

other: distilled water

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 1 mL/100 g bw

CLASS METHOD
- Rationale for the selection of the starting dose: since there was no toxicity information on the substance to be tested available, a starting dose of 300 mg/kg bw of sample suspended in vehicle was used.

Doses:

300 and 2000 mg/kg bw

No. of animals per sex per dose:

6 females (3 female rats per dosing step)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations were carried out after dosing at least once during the first 30 minutes, periodically during the first 24 hour, with special attention given during the first 4 hours and daily thereafter for a total of 14 days.
Individual weights of animals were determined shortly before the test substance was administered, weekly thereafter, and at the end of the test.
- Necropsy of survivors performed: yes, all test animals were subjected to gross necropsy.

Statistics:

not applicable

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No mortality occurred.

Clinical signs:

Animals did not show any adverse clinical sings.

Body weight:

No adverse effects on body weight were recorded.

Gross pathology:

No abnormalities were detected during necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (female rats) > 2000 mg/kg bw
According to the Regulation (EC) No 1272/2008 and subsequent adaptations, the substance is not acutely toxic via the oral route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

GLP complaint guideline study reliable for risk assessment

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:

2016-07-11 to 2016-11-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Version / remarks:

2009-09-07

Deviations:

yes

Remarks:

individual chamber conc. samples deviated from mean chamber conc. by more than ±20 %; time to chamber equilibrium was not determined; GSD on particle size determinations were > 3 µm; rel. humidity was < 30% during exposure

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2016-09-23

Test type:

acute toxic class method

Limit test:

yes

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature and protected from light

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: test material was desiccated for about 72 hours and subjected to three 60 minute-sieving rounds

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, C/Argenters 7, Local AB, 08290 Cerdanyola del Valles, Barcelona, Spain
- Females nulliparous and non-pregnant: yes
- Age at study initiation: about 9 weeks
- Weight at study initiation: mean weights 309.1 g/ 256.0 g (males/ females)
- Housing: housed in groups of three; bedding material: Capsumlab Lecho_10 (autoclavable)
- Diet (ad libitum): Teklad certified irradiated Global 14 % protein rodent maintenance diet (2914C) (Harlan Teklad, Oxon, UK)
- Water (ad libitum): tap water
- Acclimation period: 12 days

ENVIRONMENTAL CONDITIONS
- Temperature: 14.8 - 22.1 °C
- Relative humidity: 21 % - 59 %
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

1.26 µm

Remark on MMAD/GSD:

Mean mass median aerodynamic diameter of particle size distribution (PSD) (1.26 µm) was calculated from two gravimetric measurements PSD#1 and PSD#2. PSD#1 resulted in a MMAD of 0.43 µm with a geometrical standard deviation (GSD) of 5.92 and PSD#2 resulted in a MMAD of 2.08 µm with a GSD of 3.1. The GSD on PSD#1 abd Psd#2 was above the upper limit of 3 but considered acceptable as more than 73 % of particles were below the upepr limit of 4 µm in both cases (74.0 % for PSD#1 and 73.5 % for PSD#2).

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: flow-past, nose-only exposure chamber type EC-FPC-232 (anodised aluminium), equipped with glass exposure tubes were used. Before treatment start, the homogeneity for the different levels of the exposure chamber was confirmed. The exposure system ensured a uniform distribution and provided a constant flow of test material to each exposure tube. The flow of air at each tube was approximately 1 L/min, which was sufficient to minimize rebreathing of the test aerosol as it is more than twice the respiratory minute volume of rats.
- Exposure chamber volume: approx. 3 L
- Method of holding animals in test chamber: animals were confined separately in restraint tubes which were positioned radially around the exposure chamber.
Acclimatisation to the nose-only restraining tubes was performed for about 90 minutes on the day of exposure

- System of generating particulates/aerosols: a dust aerosol was generated from the desiccated and sieved test item using a Dust Generator SAG 410 (TOPAS GmbH, Germany). The dust was diluted with filtered air from a compressor and conveyed via glass tubing, from the generator to the exposure chamber. The flow rate through the exposure chamber was adjusted as necessary.

- Method of particle size determination: particle size distribution was determined gravimetrically twice during exposure. Cumulative particle size distribution of the dust was determined using a PIXE cascade impactor. Particle size distribution of the test material in the generated dust was measured bygravimetry analyzing the test item deposited on each stage of the cascade impactor. The mass median aerodynamic diameter (MMAD) and the geometric standard deviation (GSD) were calculated on the basis of the results from the impactor.

- Temperature, humidity,and air flow: temperature and relative humidity in the chamber were measured continuously during exposure using a thermohygrometer (Kimoth110, Kimo) and reported approx. hourly:
Temperature: 21.7 °C to 22.5 °C (mean value: 22.2 °C ± 0.4 °C)
Relative humidity: 17.1 % to 20.0 % (mean value: 18.6 % ± 1.2)
Exposure airflow rate was adjusted as appropriate before the start of the exposure using the pressure difference over a Venturi tube. Actual airflow rate was monitored hourly in each group during exposure. Target range was 0.5 - 1 L/min through each inhalation tube.
Mean oxygen and carbon dioxide concentrations were 20.9 % and 0.04 % respectivley.

TEST ATMOSPHERE
- Brief description of analytical method used: gravimetric determination of the dust concentration was performed once during each hour of exposure. Samples were collected onto a Whatman filter (grade F319-04) using a filter sampling device. Sampling flow was similar to the air flow rate per exposure port. Duration of sampling was 2 minutes. Filters were weighed before and immediately after sampling using a calibrated balance. Gravimetric dust concentration was calculated from the amount of test material present on the filter and the sample volume.
- Samples taken from breathing zone: yes

CLASS METHOD
- Rationale for the selection of the starting concentration: the target starting dose was 2 mg/L air. According to the results from the technical trials, this concentration was found to be the highest technically achievable that could be maintained for at least 4 hours. However, during the study a mean dose of 2.76 mg/L air could be achieved. In a technical trial, an initially dust concentration of 5 mg/L air was aimed to achieve, but saturation and blockade of the system was observed shortly after starting.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

see above "Details on inhalation exposure"

Duration of exposure:

4 h

Concentrations:

2.76 mg/L ± 1.06 (actual concentration)
2.0 mg/L (target concentration)

No. of animals per sex per dose:

3 males / 3 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: animals were examined daily for mortality and moribidity. Clinical observation were performed hourly during exposure (only grossly abnormal signs), immediately and 1 hour after exposure, and once daily thereafter until the end of the observation period. All animals were weighed on the day of treatment just before starting exposure (study day 1), on study days 2, 4, 8 and immediately before sacrifice on study day 15.
- Necropsy of survivors performed: yes, consisting of the examination of the abdominal and thoracic cavities and contents. Special attentian was paid to any change in the respiratory tract.

Statistics:

No statistical analysis was required.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.76 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: maximum attainable dose

Mortality:

No animal died prematurely.

Clinical signs:

other: No grossly abnormal signs were observed during the 4 hour exposure period. Main clinical signs after exposure were transient piloerection, loud breathing, dirty fur and prostration. Piloerection was observed in all three males and one female immediately

Body weight:

A decrease in mean body weight of approx. 7 % in males and 5 % in females was observed between study day 1 (exposure) and study day 2. From study day 2 to the end of the observation period, body weight increased gradually in all three males and in two females. In one female, a body weight decrease of ~ 1.4 % was observed between study days 8 and 15.
Mean body weight gains of approx. 13 % and 2.5 % were recorded for males and females, respectively, during the 14 days observation period.

Gross pathology:

No necropsy macroscopic findings were present in any of the animals

Interpretation of results:

GHS criteria not met

Conclusions:

LC50 (male and female rats) > 2.76 mg/L (maximum attainable dose)
According to the Regulation (EC) No 1272/2008 and subsequent adaptations, the substance is not acutely toxic via the inhalative route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity

The substance was not observed to be acutely toxic orally to female rats in a reliable study according to OECD 423. The LD50 was determined to be greater than 2000 mg/kg bw.

Acute inhalation toxicity

The substance was not observed to be acutely toxic via inhalation to male and female rats in a reliable study according to OECD 436. The LC50 was determined to be greater than 2.76 mg/L (actual concentration; maximum attainable concentration).

Acute dermal toxicity

In accordance with Annex VIII, Section 8.5, Column 2 of Regulation (EC) No. 1907/2006, in addition to the oral route (Section 8.5.1), for substances other than gases, the information mentioned under Sections 8.5.2 to 8.5.3 shall be provided for at least one other route. The choice for the second route will depend on the nature and the likely route of human exposure. In accordance with Section 8.5.3, testing by the dermal route is appropriate if: (1) inhalation of the substance is unlikely; and (2) skin contact in production and/or use is likely; and (3) the physicochemical and toxicological properties suggest potential for a significant rate of absorption through the skin. It follows that testing by the dermal route is appropriate, if all three conditions are met. The particle size distribution of the substance indicates that exposure of humans via inhalation is likely due to the possibility of exposure to particles of an inhalable size. Therefore, testing for acute toxicity by the inhalation route is appropriate and a study was conducted in accordance with Section 8.5.2.  Thus, in addition to the oral route (Section 8.5.1), the information mentioned under Sections 8.5.2 to 8.5.3 is provided for at least one other route. Since inhalation of the substance is likely, the first condition above is not met.  

In addition to the reasons mentioned above, according to Annex VIII, Section 8.5, Column 2 of Regulation (EC) No. 1907/2006 testing by the dermal route does not need to be conducted if 1) the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and 2) no systemic effects have been observed in in vivo studies with dermal exposure (e.g. skin irritation, skin sensitisation) or, in the absence of an in vivo study by the oral route, no systemic effects after dermal exposure are predicted on the basis of non-testing approaches (e.g. read across, QSAR studies). The substance does not need to be classified as acute toxic and it has no STOT SE classification by the oral route. Furthermore, no systemic effects have been observed in in vivo skin irritation and in vivo skin sensitisation studies conducted with the substance.

In conclusion, regarding the information about the substance as stated above, testing by the dermal route is not appropriate.

Justification for classification or non-classification

Acute oral toxicity

The substance is not acutely toxic via the oral route based on an acute oral toxicity test (OECD 423) and does not require classification according to Regulation (EC) No 1272/2008 and subsequent adaptations.

Specific target organ toxicant (STOT) - single exposure: oral

Reversible or irreversible adverse health effects were not observed immediately or after exposure in an acute oral toxicity test (OECD 423).Thus, the classification criteria as specific target organ toxicant (STOT) – single exposure, oral are not met and the substance does not require classification according to Regulation (EC) No 1272/2008 and subsequent adaptations.

Acute inhalation toxicity

The substance is not acutely toxic via the inhalation route based on an acute inhalation toxicity test (OECD 436) and does not require classification according to Regulation (EC) No 1272/2008 and subsequent adaptations.

Specific target organ toxicant (STOT) - single exposure: inhalation

Reversible or irreversible adverse health effects were not observed immediately or after exposure in an acute inhalation toxicity test (OECD 436).Thus, the classification criteria as specific target organ toxicant (STOT) – single exposure, inhalation are not met and the substance does not require classification according to Regulation (EC) No 1272/2008 and subsequent adaptations.