Pentapotassium triphosphate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
See read-across justification report under Section 13 ‘Assessment Reports’.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
In accordance with REACH Annex XI, Section 1.5, of Regulation (EC) No. 1907/2006 (REACH) the standard testing regime may be adapted in cases where a grouping or read-across approach has been applied.

The similarities may be based on:
(1) a common functional group
(2) the common precursors and/or the likelihood of common breakdown products via physical or biological processes, which result in structurally similar chemicals; or
(3) a constant pattern in the changing of the potency of the properties across the category

1. Both substances are inorganic salts of a monovalent cation from Group 1A of the periodic table, and triphosphoric acid. Thus, they share the Na+ or K+ cation and P3O105- anion.
2. Both the Na+ and the K+ cation have a similar biological function and therefore triphosphate salts of these types are not considered to differ in their systemic toxicity profile; differences arise in their local effects profile due to the increasing or decreasing acidity/alkalinity and buffering capacities of the substances. This has been shown not to have an effect on systemic toxicity.
3. In addition, both salts have been shown to be of similar low toxicity in acute oral studies and therefore comparisons can be drawn to allow read-across for the acute inhalation endpoint

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across justification report under Section 13 ‘Assessment Reports’.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across justification report under Section 13 ‘Assessment Reports’.

4. DATA MATRIX
See read-across justification report under Section 13 ‘Assessment Reports’.

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 81-3 (Acute inhalation toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Pentasodium triphosphate

EC Number:

231-838-7

EC Name:

Pentasodium triphosphate

Cas Number:

7758-29-4

Molecular formula:

Na5P3O10 H5-xP3O10Nax (where x is approximately 5) 6H2O.Na5P3O10

IUPAC Name:

Pentasodium triphosphate

Details on test material:

- Name of test material (as cited in study report): Sodium tripolyphosphate
- Substance type: White powder
- Purity: >90%
- Lot/batch No.: B5885327C

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Limited, Kent, UK
- Weight at study initiation: ~ 200 g
- Housing: Cages were made of polypropylene (size 38 cm x 56 cm x 18 cm height) and had detachable wire mesh tops and floors
- Diet: Free access to a measured excess amount of food (Labsure LAD 1)
- Water: Free access to water
- Acclimation period: At least 5 days prior to exposure

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Max (23) Min (19)
- Humidity (%): 63

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

not specified

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: A Wright dust generator
- Exposure chamber volume: 120 L
- Method of holding animals in test chamber: Rats were held in cages of stainless steel mesh partitioned to provide 10 individual animal compartments
- Method of conditioning air: The test atmosphere produced by the generator was passed through a glass elutriation column to reduce, by sedimentation the amount of non-respirable particulate.
- Method of particle size determination: Anderson mini-sampler
- Temperature in air chamber: Mean air temperature: 23.2°C(control) 22.6 °C (test).
- Relative humidity in air chamber: Mean relative humidity: 39% (control) 41% (test)

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

0.39 mg/L (highest attainable concentrations)

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: Weighed daily until the end of the observation period
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, lung weights

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 0.39 mg/L air

Exp. duration:

4 h

Mortality:

There were no deaths.

Clinical signs:

other: During exposure: signs consistent with exposure to an irritant dust. Partial closing of the eye, exaggerated respiratory movements, restless behaviour and excessive grooming were seen in all exposed rats. During observation period: There were no clinical

Body weight:

Small losses in body weight or a decrease in the rate of body weight gain were observed for a proportion of male rats on the day following exposure. The losses in the male rats were statistically significant 9P<0.05)

Gross pathology:

The lung weight to body weight ratio for all rats was within normal limits. Grey areas were seen ion the lungs of 1 male rat exposed to the test substance. There were no abnormalities in any other rats.

Other findings:

Food and water consumption: Food consumption was reduced for 1 day in male rats and slightly reduced for 1 day in female rats following exposure. Water consumption was slightly reduced for 1 day in male rats following exposure.

Any other information on results incl. tables

Table 1: Concentrations of sodium tripolyphosphate (Gravimetric determination):

Sample	Time	Amount in air (mg/L)
2.1	0 h:30 m	0.53
2.2	1h:00m	0.50
2.3	2h:00m	0.35
2.4	3h:00m	0.29
2.5	3h:50m	0.27
	Mean	0.39
	SD	0.120

The mean concentration of sodium tripolyphosphate was 0.39 mg/L and was the highest attainable. The concentration achieved indictaes that the test susbstance contains only a low proportion of small particles.

Table 2: Particle size distribution of sodium tripolyphosphate:

Sample	Time	Stage	Particle size range (µm)	Amount collected (mg)	% of total	% respirable
PSD 1	1h:30m	1	>5.5	1.00	64.9	35.1
		2	3.5-5.5	0.16	10.4
		3	2.0-3.5	0.20	13.0
		4	0.3-2.0	0.10	6.5
		Filter	0.3	0.08	5.2
			Totals	1.54	100.0
PSD 2	3 h:30m	1	>5.5	0.64	81.0	19.0
		2	3.5-5.5	0.02	2.5
		3	2.0-3.5	0.09	11.4
		4	0.3-2.0	0.04	5.1
		Filter	0.3	0.00	0.0
			Totals	0.79	100.0

The results in table 2 show that on average 27% of the dust collected was 5.5 µm or less in aerodynamic diameter and therefore of respirable size.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the test material caused no mortality when administered for 4 h to Wistar rats at a mean, maximum attainable concentration of 0.39 mg/L air. Based on this, the LC50 for the test material is considered to be greater than 0.39 mg/L. This study is considered to be acceptable and to adequately satisfy both the guideline requirement and the regulatory requirement for this endpoint.

As the study was conducted up to the maximum attainable concentration and in accordance with Regulation (EC) No. 1272/2008 (EU CLP) pentasodium triphosphate is not considered to be classified.
Read across from pentasodium triphosphate to pentapotassium triphosphate is justified on the following basis:
Both substances are ionic inorganic compounds containing a triphosphate anion and a group 1 alkali metal cation. Both the Na+ and the K+ cation have a similar biological function and therefore triphosphate salts of these types are not considered to differ in their systemic toxicity profile; differences arise in their local effects profile due to the increasing or decreasing acidity/alkalinity and buffering capacities of the substances. This has been shown not to have an effect on systemic toxicity.
In addition, both salts have been shown to be of similar low toxicity in acute oral studies and therefore comparisons can be drawn to allow read-across for the acute inhalation endpoint.

This study is therefore deemed reliable for classification and labeling according to Regulation (EC) No 1272/2008 (EU CLP) and further testing is considered to be scientifically unjustified.