Reaction mass of diiron carbide, diiron phosphide and triiron phosphide

Endpoint summary

Description of key information

LD50, Oral, Rats > 2000 mg/kg bodyweight.
LD50 (4 hours), Inhaled, Rats > 5.75 mg/L.

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:

11 May 2010 - 21 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to official EC and OECD test guidelines, and in compliance with GLP.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2001-12-17

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Version / remarks:

2008-05-30

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

2002-12

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

other: Crl:CD 'SD'

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 190 - 231 g
- Fasting period before study: not specified
- Housing: Animals were housed in groups of three rats of the same sex, in solid bottomed polycarbonate cages with a stainless-steel mesh lid. Each cage contained a quantity of autoclaved wood flake bedding.
- Historical data: not specified
- Diet (e.g. ad libitum): standard rodent diet (Rat and Mouse No. 1 Maintenance Diet); ad libitum (except for overnight prior to and approximately four hours after dosing)
- Water (e.g. ad libitum): Potable water taken from the public supply; ad libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 23°C
- Humidity (%): 40 - 70%
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs light

Route of administration:

oral: gavage

Vehicle:

other: 1% (w/v) aqueous methylcellulose

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 30 and 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg bw (total dose volume)

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: The dose levels for the study were chosen in compliance with the study guidelines. As no
previous toxicological information was available the initial dose level was 300 mg/kg.

Doses:

300 and 2000 mg/kg

No. of animals per sex per dose:

6 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed soon after dosing and at frequent intervals for the remainder of Day 1. On subsequent days, animals were observed once in the morning and again at the end of the experimental day (with the exception of Day 15 - morning only). The weight of each rat was recorded on Days 1 (prior to dosing), 8 and 15. Individual weekly bodyweight changes and group mean bodyweights were calculated.
- Necropsy of survivors performed: yes
- Clinical signs including body weight

Statistics:

No statistical analysis was performed on this study.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

There were no deaths during the study.

Clinical signs:

other: Clinical signs of reaction to treatment comprised faeces abnormal colour (black) seen in all females dosed at 300 mg/kg and three females (A7, A8 and A9) dosed at 2000 mg/kg. These signs were first noted approximately thirty minutes or two hours after dos

Gross pathology:

No abnormalities were noted in any animal at the macroscopic examination at study termination on Day 15.

Interpretation of results:

GHS criteria not met

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The acute median lethal oral dose (LD50) to rats of Ferrophosphorus (Fe3P) was demonstrated to be greater than 2000 mg/kg bodyweight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

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:

04 April 2011 - 11 May 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to official EC and OECD test guidelines, and in compliance with GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

2009-09-07

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Version / remarks:

1993

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Version / remarks:

1998-08

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries, Test Data for Registration of Agricultural Chemicals, 12 NohSan No. 8147

Version / remarks:

2000-11-24

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

traditional method

Limit test:

yes

Species:

rat

Strain:

other: Crl:CD® (SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd
- Age at study initiation: 49 - 56 days
- Weight at study initiation: 301 - 330 g (males) and 202-222 g (females)
- Housing: The animals were housed five of one sex per cage during the main study. The cages were made of a polycarbonate body with a stainless steel mesh lid. Wood shavings (Lignocel 3/4) were used as bedding and were sterilised by autoclaving and changed at appropriate intervals each week. Cages, food hoppers and water bottles were changed at appropriate intervals.
- Diet (e.g. ad libitum): Standard rodent diet (Rat and Mouse No. 1 Maintenance Diet). This diet contained no added antibiotic or other chemotherapeutic or prophylactic agent.
- Water (e.g. ad libitum): Potable water taken from the public supply was freely available via polycarbonate bottles fitted with sipper tubes.
- Acclimation period: At least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 23°C
- Humidity (%): 40 - 70%
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs light

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

snout only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

8 µm

Geometric standard deviation (GSD):

2.64

Remark on MMAD/GSD:

The individual and mean calculated MMAD values were above the range of 1 to 4 microns which is considered to be the optimal respirable range.

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: ADG snout-only inhalation exposure chamber, restraining tubes, a dust generator (to produce an aerosol from the powder supplied), air supply to the dust generator and extract lines, which attached to the top and bottom of the chamber respectively. A filtration system was incorporated in the extract line.
- Exposure chamber volume: ca. 30 litres
- Method of particle size determination: Cascade Impactor
- Temperature, humidity, pressure in air chamber: 20.6-25ºC, 36.2-58.9%,

TEST ATMOSPHERE
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Atmosphere samples and particle size distribution samples were determined by gravimetric analysis.

Duration of exposure:

4 h

Concentrations:

0 (Group 1) and 5.75 (Group 2) mg/L (mean achieved aerosol concentration; target concentration: 5 mg/L)

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: During the observation period, the animals were observed once in the morning and once toward the end of the experimental day. On the day of termination observations were recorded in the morning only.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical observations (at least twice daily through the observation period), mortality (all cages checked at least twice daily), bodyweight (The weight of each animal was recorded on Day 1 (prior to dosing), 2, 4, 8 and 15).

Statistics:

No statistical analysis was performed on this study.

Preliminary study:

In view of the limited data toxicity available, and as allowed for in the regulatory guidelines a preliminary exposure, using 1 male and 1 female rat, was conducted at the target (Limit test) concentration of 5 mg/L for a period of 4-hours in order to assess the likely response of rats to the test substance. As a concentration of 4.91 mg/L was tolerated by the preliminary animals, the main study test animals were also exposed to the target concentration of 5 mg/L for a period of 4-hours.

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.75 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: The individual and mean achieved aerosol concentration values are higher than the target of 5 mg/L. The highest achieved chamber aerosol concentration was 9.35 mg/L. The lowest value was 4.87 mg/L.

Mortality:

There were no unscheduled deaths.

Clinical signs:

other: Grey staining of head (transient; evident for all Group 2 animals); grey staining of the forepaws (transient; evident for the majority of Group 2 animals); wet fur (both groups; higher incidence in Group 2) considered related to the restraint procedure.

Body weight:

There were no treatment related effects on bodyweight.

Gross pathology:

The macroscopic examination performed after a single exposure and a 14 day observation period revealed the following intergroup differences:
- A dark (brown) appearance of the lungs was evident in all Group 2 animals.
- Enlargement of the tracheobronchial lymph nodes was observed in two males and all females of Group 2.
- The nature and incidence of all other findings were consistent with the commonly seen background of macroscopic changes.

Other findings:

- Organ weights: Group mean lung weights for Group 2 were higher when compared with Controls, 1.49 X and 1.46 X for males and females respectively.

Interpretation of results:

GHS criteria not met

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study the LC50 (4 hour) of Fe3P is in excess of 5.75 mg/L for male and female rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

An acute oral toxicity study in rats was conducted (Huntingdon Life Sciences, 2010) to determine the acute LD₅₀ of Fe₃P when administered orally. The study was conducted according to EC test guideline B1, OECD guideline 423, and US EPA and Japanese test guidelines, and in compliance with GLP.

Two groups of three fasted female rats received a single oral gavage dose at 300 mg/kg bodyweight; as the results at this level indicated that the LD50 was greater than 300 mg/kg bodyweight, a further two groups of three fasted females received a single oral gavage dose of 2000 mg/kg bodyweight.

There were no deaths during the study. The only clinical sign of a reaction to treatment noted during the observation period was abnormally coloured faeces (black) seen in all animals dosed at 300 mg/kg, and three females dosed at 2000 mg/kg; these signs had resolved by day 2 of observation. A low bodyweight gain was observed late in the observation period for two animals at 300 mg/kg and three animals dosed at 2000 mg/kg. No abnormalities were noted in any animal during the macroscopic examination at study termination.

The acute median lethal oral dose to rats was demonstrated to be greater than 2000 mg/kg bodyweight.

 

An acute inhalation toxicity study in rats was conducted (Huntingdon Life Sciences, 2011) to determine the acute LD₅₀ of Fe₃P by inhalation exposure. The study was conducted according to EC test guideline B2, OECD test guideline 403, and US EPA and Japanese test guidelines, and was performed in compliance with GLP.

1 control group and 1 test group each consisting of 5 male and 5 female Sprague Dawley rats were exposed for 4-hours snout-only, then observed over 14 days prior to sacrifice and macropathological examination. The time-weighted average aerosol concentration of Fe₃P in the treated group was 5.75 mg/L, which was close to the target concentration of 5 mg/L. Individual and mean calculated Mass median aerodynamic diameter (MMAD) values were slightly above the optimal range of 1 - 4 µm; the average MMAD was 8 µm.

There were no unscheduled deaths during the study. Clinical signs were limited to grey staining of the head in all animals of the treated group, and the forepaws in the majority of animals in the treatment group. This was no longer evident at the first check during the observation period. There were no treatment related effects on bodyweight. Macroscopic pathological examination following sacrifice revealed a dark brown colour in the lungs of treated animals, a higher relative weight of lungs in the treated group by comparison to the control group, and enlarged tracheobronchial lymph nodes seen in treated animals.

The LC₅₀ (4 hour) in rats of Fe₃P was found to be greater than 5.75 mg/L under the conditions applied during this test.

Justification for classification or non-classification

The oral LD₅₀ in rats of Fe₃P was determined to be greater than 2000 mg/kg bodyweight. According to both the Classification Labelling and Packaging Regulation (CLP, EC number 1272/2008), classification for acute oral toxicity only applies where the oral LD₅₀ in rats is equal to or less than 2000 mg/kg bodyweight; on this basis Fe₃P is not classified for acute oral toxicity.

The inhalation LC₅₀ in rats of Fe₃P was determined to be greater than 5 mg/L. According to both the CLP Regulation and the DSD as above, classification for acute inhalation toxicity only applies where the inhaled LC₅₀in rats is equal to or less than 5 mg/L; on this basis Fe₃P is not classified for acute inhaled toxicity.

 

Although the studies noted above were designed to determine the lethal dose / concentration of Fe3P, and signs of sublethal toxicity were not observed in detail, the macroscopic pathology in each case did not indicate Specific Target Organ Toxicity (STOT, single exposure) by either administration route. The differences between the lungs of the treated group animals and the control group animals seen in the acute inhalation study (Huntingdon Life Sciences, 2011) were expected, and relate to the presence of test material in the lungs of the treated animals (increased lung weights and dark brown colour in the lungs) and the elimination response (enlarged tracheobronchial lymph nodes); these observations are not indicators of toxicity.

On this basis, Fe₃P is not classified for STOT following single exposure by either the oral or inhalation exposure routes.