Iron orthophosphate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10th October 2011 - 17 November 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Iron orthophosphate

EC Number:

233-149-7

EC Name:

Iron orthophosphate

Cas Number:

10045-86-0

Molecular formula:

FePO4

IUPAC Name:

iron(3+) phosphate

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Source:
Harlan (UK) Ltd.

- Age at study initiation:
approximately eight to twelve weeks old

- Weight at study initiation:
200g to 350g.

- Fasting period before study:
Not applicable

- Housing:
The animals were housed in solid-floor polypropylene cages with stainless steel lids, furnished with softwood flakes and provided with environmental enrichment items: wooden chew blocks and cardboard “fun tunnels”

- Diet:
ad libitum

- Water:
ad libitum

- Acclimation period:
at least five days


ENVIRONMENTAL CONDITIONS

- Temperature:
19 - 25°C

- Humidity:
30 - 70 %

- Air changes (per hr):
at least fifteen changes per hour

- Photoperiod (hrs dark / hrs light):
twelve hours continuous light and twelve hours darkness


IN-LIFE DATES:
From: 26 October 2011 To: 17 November 2011

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

2.96 µm

Geometric standard deviation (GSD):

3.22

Remark on MMAD/GSD:

Inhalable Fraction (% <4 µm) 60.2

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:
a SAG 410 Solid Aerosol Generator (TOPAS GmbH, Dresden, Germany) plus cylindrical exposure chamber

- Exposure chamber volume:
approximately 30 litres

- Method of holding animals in test chamber:
Each rat was individually held in a tapered, polycarbonate restraining tube fitted onto a single tier of the exposure chamber and sealed by means of a rubber ‘O’ ring. Only the nose of each animal was exposed to the test atmosphere.

- Source and rate of air:
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. 60 L/min providing 120 air changes per hour

- Method of conditioning air:
water trap and respiratory quality filters

- System of generating particulates:
SAG 410 Solid Aerosol Generator , a particle separator was introduced before the aerosol entered the exposure chamber in order to remove large particles and thereby increase the inhalable portion of the generated aerosol.

- Method of particle size determination:
Marple Personal Cascade Impactor .

- Treatment of exhaust air:
filtered

- Temperature, humidity, pressure in air chamber: temperature and relative humidity inside the exposure chamber were measured by an electronic thermometer/humidity meter 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:
glass fibre filters (Gelman type A/E 25 mm) 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 (Gravimetric).

- Samples taken from breathing zone:
yes


VEHICLE
- Composition of vehicle (if applicable):
Not applicable

- Concentration of test material in vehicle:
Not applicable

- Justification of choice of vehicle:
Not applicable

- Lot/batch no. (if required):
Not applicable

- Purity: Not applicable


TEST ATMOSPHERE (if not tabulated)

- Particle size distribution: tabulated
- MMAD (Mass median aerodynamic diameter: 9.93 µm

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: Not applicable.

Analytical verification of test atmosphere concentrations:

no

Remarks:

Gravimetric only

Duration of exposure:

4 h

Concentrations:

Mean Achieved (mg/L) 5.05

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 Individual bodyweights were recorded on arrival, prior to treatment on the day of exposure and on Days 1, 3, 7 and 14.

- Necropsy of survivors performed: yes

- Other examinations performed: clinical signs.

Statistics:

Data evaluations included the relationship, if any, between the animals’ exposure to the test material 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 material was made.

Results and discussion

Preliminary study:

Not applicable

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.05 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of 5.05 mg/L for four hours
See Appendix 3 Mortality Data in the overall remarks section.

Clinical signs:

other: Common abnormalities noted during the study included increased respiratory rate, hunched posture, pilo-erection and wet fur. See Appendix 4 Individual Clinical Observations(Day of Exposure) and Appendix 5  Individual Clinical Observations (Recovery Peri

Body weight:

All animals exhibited bodyweight losses or showed no bodyweight gain on the first day post-exposure. All animals exhibited reasonable bodyweight developments throughout the remainder of the recovery period. With the exception of one female animal which showed no bodyweight gain from Days 3 to 7 post-exposure. See Appendix 6.
Appendix 6 Individual Bodyweights in the overall remarks section.

Gross pathology:

No macroscopic abnormalities were detected amongst animals at necropsy.

Other findings:

Not applicable.

Any other information on results incl. tables

Exposure Chamber Concentration

The test atmosphere was sampled seventeen times during the exposure period and the actual concentration of the test item calculated. The mean values obtained were:

Atmosphere Concentration
Mean Achieved (mg/L)	Standard Deviation	Nominal (mg/L)
5.05	0.11	9.22

The chamber flow rate was maintained at 60 L/min providing 120 air changes per hour.The theoretical chamber equilibration time (T₉₉) was 3 minutes (Silver, 1946). However,Test atmospheres were generated for a total of 24 minutes prior to animal insertion to ensure test item concentration was being achieved.

Particle Size Distribution

The particle size analysis of the atmosphere drawn from the animals’ breathing zone, was as follows:

Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (µm)	Inhalable Fraction (% <4 µm)	Geometric Standard Deviation
5.05	2.96	60.2	3.22

Mortality Data

The mortality data are given in Appendix 3 and are summarised as follows:

Mean Achieved Atmosphere Concentration (mg/L)	Deaths
	Male	Female	Total
5.05	0/3	0/3	0/6

Appendix1      Exposure Chamber Atmosphere Concentrations

Duration of Exposure (minutes)	Net Weight of Sample (mg)	Volume of Air Sampled (L)	Chamber Flow Rate (L/min)	Atmosphere Concentration (mg/L)
5	10.04	2	60	5.02
15	9.94	2	60	4.97
30	10.11	2	60	5.06
45	10.04	2	60	5.02
60	9.91	2	60	4.96
75	10.26	2	60	5.13
90	10.11	2	60	5.06
105	10.11	2	60	5.06
120	10.25	2	60	5.13
135	10.16	2	60	5.08
150	10.71	2	60	5.36
165	9.85	2	60	4.93
180	10.06	2	60	5.03
195	9.75	2	60	4.88
210	9.78	2	60	4.89
225	10.31	2	60	5.16
238	10.12	2	60	5.06

Mean achieved atmosphere concentration (mg/L) =5.05

Standard deviation =0.11

Nominal concentration:

Test item used (g)	146
Air Flow (L/min)	60
Total Generation Time (mins)	264
Nominal Concentration (mg/L)	9.22

[1]= Test atmospheres were generated for a total of 24 minutes prior to animal insertion to ensure test item concentration was being achieved.

Appendix2      Particle Size Distribution

Cascade Impactor Data

Impactor Stage Number	Cut Point (µm)	Amount Collected (mg) per Sample Number			Mean Amount Collected (mg)
		1	2	3
3	8.8	0.33	0.29	0.04	0.22
4	5.8	0.45	0.50	0.10	0.35
5	3.6	0.38	0.37	0.20	0.32
6	1.9	0.59	0.62	0.33	0.51
7	0.79	0.11	0.14	0.34	0.20
8	0.33	0.14	0.12	0.15	0.14
Back-up Filter	<0.33	0.04	0.06	0.20	0.10
Total Mean Amount of Test Item Collected					1.84

Calculation

Cut Point (µm)	Log10 Cut Point	Mean Cumulative Amount Less Than Cut Point
		(mg)	(%)	Probit
8.8	0.945	1.62	88.0	6.18
5.8	0.763	1.27	69.0	5.50
3.6	0.556	0.95	51.6	5.04
1.9	0.279	0.44	23.9	4.29
0.79	-0.102	0.24	13.0	3.88
0.33	-0.482	0.10	5.44	3.40

Results

Mean Mass Median Aerodynamic Diameter (MMAD) =2.96µm

Geometric Standard Deviation (GSD) =3.22

Predicted amount less than 4 µm =60.2%

Appendix 3        Mortality Data

Mean Achieved Atmosphere Concentration (mg/L)	Sex	Deaths During Exposure	Deaths Post Exposure (1 Hour)	Deaths During Day of Observation								Total Deaths
				1	2	3	4	5	6	7	8-14
5.05	Male	0	0	0	0	0	0	0	0	0	0	0/6
	Female	0	0	0	0	0	0	0	0	0	0

Appendix 4    Individual Clinical Observations(Day of Exposure)

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Hours During Exposure			On Removal From Chamber	One Hour Post-Exposure
		1	2	3
5.05	1 Male	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	2 Male	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	3 Male	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	4 Female	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	5 Female	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	6 Female	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri

Appendix 5    Individual Clinical Observations (Recovery Period)

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Days Post Exposure
		1	2	3	4	5	6	7	8 - 14
5.05	1 Male	H Ri	0	0	0	0	0	0	0
	2 Male	H Ri	0	0	0	0	0	0	0
	3 Male	H Ri	0	0	0	0	0	0	0
	4 Female	H Ri	Ri	Ri	Ri	0	0	0	0
	5 Female	H Ri	Ri	Ri	Ri	0	0	0	0
	6 Female	H Ri	Ri	Ri	Ri	0	0	0	0

Appendix 6    Individual Bodyweights.

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Bodyweight (g) on Day:						Increment (g) During Days:
		-8	0	1	3	7	14	-8-0	0-1	1-3	3-7	7-14
5.05	1 Male	215	257	250	260	276	299	42	-7	10	16	23
	2 Male	223	274	264	268	289	318	51	-10	4	21	29
	3 Male	215	278	278	287	303	333	63	0	9	16	30
	4 Female	191	202	198	199	199	205	11	-4	1	0	6
	5 Female	202	218	217	222	227	239	16	-1	5	5	12
	6 Female	199	212	208	213	217	224	13	-4	5	4	7

Applicant's summary and conclusion

Interpretation of results:

other: CLP/EU GHS criteria are not met, no classification required according to Regulations (EC) No 1272/2008

Conclusions:

No deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of 5.05 mg/L for four hours. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of IP 27 Iron orthophosphate, in the RccHanTM : WIST strain rat, was greater than 5.05 mg/L (Globally Harmonised Classification System – Unclassified). This study is considered to be scientifically justified for use as a key study under Regulation (EC) No. 1907/2006 and the results are appropriate for the purposes of classification and labelling in accordance with Regulation (EC) No. 1272/2008 (EU CLP).

Executive summary:

Introduction.

A study was performed to assess the acute inhalation toxicity of the test item. The method used was compatible with that described in the OECD Guidelines for Testing of Chemicals (2009) No. 436 “Acute Inhalation Toxicity – Acute Toxic Class Method”.

Methods.

A group of six RccHan^TM: WIST strain rats (three males and three females) was exposed to a dust atmosphere. The animals were exposed for four hours using a nose only exposure system, followed by a fourteen day observation period.

Results.The mean achieved atmosphere concentration was as follows:

Atmosphere Concentration
Mean Achieved (mg/L)	Standard Deviation	Nominal (mg/L)
5.05	0.11	9.22

The characteristics of the achieved atmosphere were as follows:

Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (µm)	Inhalable Fraction (% <4 µm)	Geometric Standard Deviation
5.05	2.96	60.2	3.22

The mortality data were summarised as follows:

Mean Achieved Atmosphere Concentration (mg/L)	Deaths
	Male	Female	Total
5.05	0/6	0/6	0/6

Clinical Observations.

Common abnormalities noted during the study included increased respiratory rate, hunched posture, pilo-erection and wet fur. Animals recovered to appear normal from Days 2 to 5 post-exposure.

Bodyweight.

All animals exhibited bodyweight losses or showed no bodyweight gain on the first day post-exposure. All animals exhibited reasonable bodyweight developments throughout the remainder of the recovery period. With the exception of one female animal which showed no bodyweight gain from Days 3 to 7 post-exposure. 

Necropsy.

No macroscopic abnormalities were detected amongst animals at necropsy.

Conclusion.No deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of5.05mg/L for four hours. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC₅₀) of IP 27 Iron orthophosphate, in the RccHan^TM: WIST strain rat, was greater than 5.05mg/L (Globally Harmonised Classification System – Unclassified).