Tetrairon tris(pyrophosphate)

Endpoint summary

Description of key information

Key studies are available for acute oral and acute inhalation toxicity. These studies are performed under the conditions of GLP and to an appropriate OECD guideline. As such, these studies are considered to be adequate and reliable for use a key studies for the purpose of REACH Registration and classification and labelling in accordance with EU CLP. It is not considered necessary to provide acute dermal toxicity data on the basis of the physiochemical and toxicological properties of tetrairon tris(pyrophosphate).

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:

The study was performed between 13 April 2010 and 05 May 2010.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted to GLP and in compliance with agreed protocols, with no deviations from standard test guidelines (OECD 420, EU Method B1 bis) and no methodological deficiencies. This study has been selected as the key study because the results are sufficient in order to derive a reliable conclusion on classification and labelling in accordance with Regulation (EC) No. 1272/2008 (EU CLP).

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 19-21 July 2011, Date of signature: 31 August 2011

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Limited, Oxon, UK.
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 165-189 g. The bodyweight variation did not exceed ± 20% of the initial/mean bodyweight of any previously dosed animal(s).
- Fasting period before study: overnight fast immediately before dosing.
- Housing: The animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes.
- Diet (e.g. ad libitum): ad libitum (2014C Teklad Global Rodent diet supplied by Harlan Teklad, Oxon, UK)
- Water (e.g. ad libitum): 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 per hour
- Photoperiod (hrs dark / hrs light): twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

IN-LIFE DATES: From: 15 May 2012 To: 07 June 2012

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Route of administration:

oral: gavage

Vehicle:

water

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were made ½, 1, 2, and 4 hours after dosing and subsequently once daily for fourteen days. Morbidity and mortality checks were made twice daily. Individual bodyweights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.
- Necropsy of survivors performed: yes
At the end of the observation period the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths in the 5 animals tested.

Clinical signs:

other: Individual clinical observations and mortality data are given in Table 1. No signs of systemic toxicity were noted.

Gross pathology:

Individual necropsy findings are given in Table 3.
No abnormalities were noted at necropsy.

Table 1. Individual clinical observations and mortality data.

 

 

Dose level mg/kg	Animal number and sex	Effects noted after dosing (hours)				Effects noted during periods after doing (days)
		½	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	1-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-1 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-2 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-3 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

 

 

 

Table 2. Individual bodyweight and bodyweight changes

 

Dose level mg/kg	Animal number and sex	Bodyweight (g) at day			Bodyweight gain (g) during week
		0	7	14	1	2
2000	1-0 Female	165	193	206	28	13
	2-0 Female	189	210	218	21	8
	2-1 Female	177	197	208	20	11
	2-2 Female	179	191	204	12	13
	2-3 Female	177	201	215	24	14

 

 

 

Table 3. Individual Necropsy Findings

 

Dose level mg/kg	Animal number and sex	Time of death	Macroscopic observations
2000	1-0 Female	Killed day 14	No abnormalities detected
	2-0 Female	Killed day 14	No abnormalities detected
	2-1 Female	Killed day 14	No abnormalities detected
	2-2 Female	Killed day 14	No abnormalities detected
	2-3 Female	Killed day 14	No abnormalities detected

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral median lethal dose (LD50) of the test material in the female Wistar strain rat was estimated to be greater than 2000 mg/kg bodyweight (Globally Harmonised Classification System: Unclassified).
This study is considered to be reliable and acceptable for use as a key study in accordance with Regulation (EC) No. 1907/2006 (REACH) and for the purposes of classification and labelling in accordance with Regulation (EC) No. 1272/2008 (EU CLP).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

One study exists: study is conducted to GLP and in compliance with agreed protocols, with no deviations from standard test guidelines (OECD 420) and no methodological deficiencies.
The LD50 was found to be > 2000 mg/kg bw.

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:

The study was performed between 01 May 2012 and 23 May 2012.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted to GLP and in compliance with agreed protocols, with no deviations from standard test guidelines (OECD 436) and no methodological deficiencies. This study has been selected as the key study because the results are sufficient in order to derive a reliable conclusion on classification and labelling in accordance with Regulation (EC) No. 1272/2008 (EU CLP).

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Deviations are discussed under 'results'. Any deviations are not considered to affect the validity of the results.

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of Inspection: 19-12 July 2011 Date of signature: 31 August 2011

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Source: Harlan Laboratories UK Ltd, Oxon, UK
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: weight range of 200g to 350g
- Fasting period before study: Not applicable
- Housing: Animals were housed in groups of 3 of the same sexin 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): Animals had ad libitum access to standard Harlan Teklad 2914C rat maintenance diet (Harlan 2014C Rodent Diet, Harlan Laboratories UK Ltd, Oxon, UK). Results of the analyses for contaminants and their limits of acceptability are archived at Harlan Laboratories Ltd.
- Water (e.g. ad libitum): Ad libitum. Results of representative analyses for contaminants are archived at Harlan Laboratories Ltd.
- Acclimation period: For at least 5 days under laboratory conditions, after clinical health examination. Only animals without any visible signs of illness were used for the study. A further observation of clinical signs was performed on the day of exposure, before exposure start.


ENVIRONMENTAL CONDITIONS
Temperature: 19-25°C
Humidity: 30-70%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): the lighting was controlled to give twelve hours continuous light and twelve hours darkness.

The animals were retained in this accommodation at all times except during the exposure period.


IN-LIFE DATES: From: Day 1 To: Day 14

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

clean air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION

- Exposure apparatus: 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.

- Exposure chamber volume: The cylindrical exposure chamber had a volume of approximately 30 litres (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.


- Method of holding animals in test chamber: The animals were confined separately in restraint tubes which were positioned radially around the flow-past, nose-only exposure chamber. Only the nose of each animal was exposed to the test atmosphere.
- Source of air: Compressed air was supplied by means of an oil free compressor and passed respiratory quality filters before it was introduced into the exposure system.
- Exposure Chamber Atmosphere Concentration: The actual chamber concentration was measured at regular intervals during the exposure period. The gravimetric method used glass fibre filters placed in a filter holder. The holder was temporarily sealed in a vacant port in the exposure chamber in the animals’ breathing zone and a suitable, known volume of exposure chamber air was drawn through the filter using a vacuum pump.
Each filter was weighed before and after sampling in order to calculate the weight of collected test item. The difference in the two weights, divided by the volume of atmosphere sampled, gave the actual chamber concentration.
The nominal chamber concentration was calculated by dividing the mass of test item used by the total volume of air passed through the chamber.
The nominal concentration is 817% of the actual mean achieved atmosphere concentration and shows that keeping the aerosol airborne was difficult.
- Temperature, humidity, pressure in air chamber: 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.

TEST ATMOSPHERE

- Brief description of analytical method used: Homogeneity of the test atmosphere within the chamber was not specifically determined during this study. Chambers of the same design (ADG Developments Ltd, Hitchin, Herts, UK) have been fully validated and shown to produce evenly distributed atmospheres in the animals’ breathing zone with a wide variety of test items (Green J D et al, 1984).
Prior to the start of the study, test item atmospheres were generated within the exposure chamber. During this characterisation period test item input rates were varied in order to achieve the required atmospheric conditions.

-Exposure chamber oxygen concentration: Oxygen levels within the exposure chamber were measured by an electronic oxygen analyser (Servomex (UK) Ltd, Crowborough, East Sussex) located in a port in the animals breathing zone during the characterisation phase of the study, the test atmosphere was generated to contain at least 19% oxygen. Due to a malfunction it was not possible to determine oxygen concentrations during the four hour exposure period.


- Samples taken from breathing zone: Yes

.

Analytical verification of test atmosphere concentrations:

no

Remarks:

Gravimetric only

Duration of exposure:

4 h

Concentrations:

Mean Achieved (mg/L) 5.19
The nominal aerosol concentration was 42.4 mg/L air.
The chamber flow rate was maintained at 60 L/min providing 120 air changes per hour.

Mean Mass Median Aerodynamic Diameter (µm): 4.22
Inhalable Fraction (% <4 µm): 48.3%
Geometric Standard Deviation: 3.63

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration:
14 days

- Frequency of observations and weighing:
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 after termination of exposure and subsequently once daily for fourteen days. Individual bodyweights were recorded prior to treatment on the day of exposure and on Days 1, 3, 7 and 14.

- Necropsy of survivors performed:
yes
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.

- Other examinations performed:
None
Data evaluations included the relationship, if any, between the animals’ exposure to the test item and the incidence and severity of all abnormalities including behavioural and clinical observations, necropsy findings, bodyweight 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.

Statistics:

No statistical analysis was performed as only one group was allocated to the study.

Preliminary study:

Not applicable

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.19 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: CL not given

Mortality:

All animals survived the scheduled observation period.

Clinical signs:

other: Signs of hunched posture, pilo-erection and red/brown staining around the eyes and/or snout 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

Body weight:

All animals exhibited bodyweight losses or showed no bodyweight gains on the first day post-exposure. All animals exhibited bodyweight gains during the remainder of the recovery period, with the exception of one female animal which a slight bodyweight loss from Days 1 to 3 post-exposure.

Gross pathology:

With the exception of one instance of dark patches on the lungs, no macroscopic abnormalities were detected amongst animals at necropsy.

Other findings:

Not applicable.

It is noted that the MMAD and GSD exceed the ranges given in the test guidelines (1-4 μm and 1.5 – 3.0 respectively). These deviations are considered to be due to the physical characteristics of the test item, even after significant grinding these values could not be improved further. These results show that the aerosol concentration achieved was at the technical limit with a respirable particle size.

At a mean achieved concentration of 5.19 mg/L the animals were exposed to approximately 2.51 mg/L particles <4 μm. It must be noted that if a MMAD of 4 μm had been achieved at a concentration of 5 mg/L then the approximate concentration of particle that the animals would have been exposed to that were <4 μm would have been 2.50 mg/L. Therefore, it can be considered that the slight increase in the MMAD achieved during this study is considered not to be significant.

It was not possible to determine oxygen concentrations for the formal exposure due to a malfunction of the oxygen analyser, however, as the oxygen concentration was taken during the characterisation phase of the study it can be concluded that this test item does not deplete oxygen. It can therefore be considered that the oxygen concentration would have been maintained above 19 % as per the characterisation phase of the study.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

No deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of 5.19 mg/L for four hours. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of Tetrairon tris (pyrophosphate), in the RccHanTM : WIST strain rat, was greater than 5.19 mg/L (Globally Harmonised Classification System – unclassified).
This study is conducted according to an appropriate guideline and under the conditions of GLP, the study is therefore considered to be acceptable and to adequately satisfy both the guideline requirement and the regulatory requirement as a key study for this endpoint.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

One study exists: study is conducted to GLP and in compliance with agreed protocols, with no deviations from standard test guidelines (OECD 436) and no methodological deficiencies affecting the validity of the results.
The LC50 was found to be > 5.19 g/L.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Section 8.5.3: Adaptation

In accordance with Annex VIII, Section 8.5.3, Column 2 of Regulation (EC) No. 1907/2006 (REACH) 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 suggest a potential for a significant rate of absorption through the skin.

Although skin contact is likely during production and use of tetrairon tris(pyrophosphate), inhalation of the substance is also likely and as such an acute inhalation study has been performed. Tetrairon tris(pyrophosphate) is an inorganic chemical with a molecular weight of >100 and is practically insoluble in water and lipids, therefore, systemic absorption via the dermal route is unlikely and as such inhalation and oral routes are considered to be a worst-case for systemic absorption.

As dermal absorption will be considerably less via the dermal route as opposed to the oral route it can be reliably assumed that a full characterisation of the acute systemic toxicity profile of tetrairon tris(pyrophosphate) can be derived from the acute oral and inhalation studies and as such further in vivo testing would be unethical and could not be scientifically justified.

Justification for selection of acute toxicity – oral endpoint
This study has been selected as the key study because the results are sufficient in order to derive a reliable conclusion on classification and labelling in accordance with Regulation (EC) No. 1272/2008 (EU CLP).

Justification for selection of acute toxicity – inhalation endpoint
This study has been selected as the key study because the results are sufficient in order to derive a reliable conclusion on classification and labelling in accordance with Regulation (EC) No. 1272/2008 (EU CLP).

Justification for selection of acute toxicity – dermal endpoint
No study selected as an adaptation to the standard testing regime has been submitted.

Justification for classification or non-classification

Acute oral toxicity: The oral LD₅₀has been determined to be > 2000 mg/kg bw and therefore in accordance with Regulation (EC) No. 1272/2008 (EU CLP) tetrairon tris(pyrophosphate) is not considered to be classified as acutely toxic via the oral route.

Acute inhalation toxicity: The LC₅₀has been determined to be > 5.19 mg/L and therefore in accordance with Regulation (EC) No. 1272/2008 (EU CLP) tetrairon tris(pyrophosphate) is not considered to be classified as acutely toxic via the inhalation route.

 

Acute dermal toxicity: Based on considerations of the physicochemical and toxicological properties of tetrairon tris(pyrophosphate), the substance is not considered to be classified as acutely toxic via the dermal route. Further in vivo testing is not scientifically justified.