Superphosphates

Endpoint summary

Description of key information

No reliable skin irritation study with single superphosphate is available. Based on a reliable in vivo study with ammonium dihydrogenorthophosphate showing no or minimal irritation, it is concluded that that the substance is not irritating to skin. This is confirmed by a study with calcium (bisdihydrogenorthophosphate). Based upon a reliable in vivo eye irritation study with single superphosphate, the substance is considered an eye irritant.The read-across rationale can be found in the category approach document attached in Section 13 of IUCLID and is fully incorporated in the CSR.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

24 h exposure under occlusive conditions

GLP compliance:

no

Species:

rabbit

Strain:

Vienna White

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g
- Concentration (if solution): 80%

Duration of treatment / exposure:

24 h

Observation period:

9 days

Number of animals:

3 male and 3 female

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24 h

Score:

1

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24 h

Score:

1

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

0

Irritation parameter:

erythema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0

Irritation parameter:

erythema score

Basis:

animal #6

Time point:

24 h

Score:

1

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Table 1 Erythema and edema results of the skin irritation study

	time	animal 1	animal 2	animal 3	animal 4	animal 5	animal 6
erythema	24 h	1	1	0	0	0	1
	72 h	0	0	0	0	0	0
	9 d	0	0	0	0	0	0
edema	24 h	0	0	0	0	0	0
	72 h	0	0	0	0	0	0
	9 d	0	0	0	0	0	0

Interpretation of results:

GHS criteria not met

Remarks:

Not classified according to Regulation (EC) No. 1272/2008

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 June 2010 - 14 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000, including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Kisslegg, Germany (animal no. 1) and Harlan, Belton, Leics, England (animal nos. 2 and 3)
Use of an animal from a different source than protocolled (Harlan France or UK) is considered to have no adverse effect on the study outcome or interpretation of results since the same strain of rabbit was used and the animal was of an appropriate age and weight.
- Age at study initiation: Animals used within the study were at least 6 weeks old
- Weight at study initiation: body weights were at least 1.0 kg.
- Housing: labeled cages with perforated floors (Ebeco, Germany, dimensions 67 x 62 x 55 cm) and shelters (Ebeco, Germany, dimensions 40 x 32 x 23 cm).
- Diet (e.g. ad libitum): Pelleted diet for rabbits (Global Diet 2030 from Harlan Teklad®, Mucedola, Milanese, Italy) approximately 100 grams per day. Hay (TecniLab-BMI BV, Someren, The Netherlands) was provided at least three times a week.
- Water (e.g. ad libitum): Free access to tap water.
- Acclimatization period: at least 5 days before start of treatment under laboratory conditions.

A health inspection was performed prior to commencement of treatment, to ensure that the animals were in a good state of health. Special attention was paid to the eyes, which were free from any abnormality.

Results of analysis for diet (nutrients and contaminants), hay and water were assessed and did not reveal any findings that were considered to have affected the study integrity. All certificates and results of analysis are retained in the NOTOX archives.

Animal specifications (sex, age and body weight) are specified in the attached table.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.1 – 20.0ºC
- Humidity (%): 37 - 84%
Temporary deviations from the maximum and minimum level of relative humidity occurred. Laboratory historical data do not indicate an effect of the deviations.
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 hours artificial fluorescent light and 12 hours darkness per day

IN LIFE DATES: From: 10 June 2010 To: 14 July 2010

Vehicle:

unchanged (no vehicle)

Controls:

other: One eye of each animal remained untreated and served as the reference control.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volulme or weight with unit): average: 89.3mg (range 89.1 – 89.5 mg) (a volume of approximately 0.1 mL)

Duration of treatment / exposure:

Single instillation on Day 1

Observation period (in vivo):

The eyes of each animal were examined approximately 1, 24, 48 and 72 hours and 7, 14 and 21 days after instillation of the test substance

Number of animals or in vitro replicates:

3 males

Details on study design:

STUDY DESIGN
The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). The two other animals were treated in a similar manner approximately 2 weeks later, after considering the degree of eye irritation observed in the first animal.

TREATMENT
Animals were treated by instillation of, on average, 89.3mg (range 89.1 – 89.5 mg) of the test substance (a volume of approximately 0.1 mL) as the maximum required amount in the conjunctival sac of one of the eyes after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second to prevent loss of the test substance. The other eye remained untreated and served as the reference control.

Immediately after the 24-hour observation, a solution of 2% fluorescein (Merck, Darmstadt, Germany) in water (adjusted to pH 7.0) was instilled into both eyes of each animal to quantitatively determine corneal epithelial damage. Any bright green stained area, indicating epithelial damage, was estimated as a percentage of the total corneal area.

After the final observation, the animals were sacrificed by intra-venous injection of Euthasol® 20% (AST Farma BV, Oudewater, The Netherlands).

REMOVAL OF TEST SUBSTANCE
-Washing (if done): No

OBSERVATIONS
- Mortality/Viability: Twice daily.
- Toxicity: At least once daily.
- Body Weight: Day of treatment (prior to instillation) and after the final observation.
- Necropsy: No necropsy was performed according to protocol.
- Irritation:
The eyes of each animal were examined approximately 1, 24, 48 and 72 hours and 7, 14 and 21 days after instillation of the test substance.
The irritation scores and a description of all other (local) effects were recorded.The irritation was assessed according to the following numerical scoring system. At each observation, the highest scores given were recorded:

CORNEAL IRRITATION
0: Opacity: degree of density (area most dense taken for reading)
1: No ulceration or opacity (may include slight dulling of normal luster)
2: Scattered or diffuse areas of opacity, details of iris clearly visible
3: Easily discernible translucent area, details of iris slightly obscured
4: Nacreous area, no details of iris visible, size of pupil barely discernible
5: Opaque cornea, iris not discernible through the opacity

Area of cornea involved:
0: No ulceration or opacity
1: One quarter or less but not zero
2: Greater than one quarter, but less than half
3: Greater than half, but less than three quarters
4: Greater than three quarters, up to whole area

IRIS
0: Normal
Markedly deepened rugae, congestion, swelling, moderate circumcorneal hyperaemia,
or injection, any of these or combination thereof, iris still reacting to light
1: (sluggish reaction is positive)
2: No reaction to light, hemorrhage, gross destruction (any or all of these)

CONJUNCTIVAL IRRITATION
Redness (refers to palpebrae and sclera, excluding cornea and iris):
0: Blood vessels normal
1: Some blood vessels definitely hyperaemic (injected)
2: Diffuse, crimson color, individual vessels not easily discernible
3: Diffuse beefy red

Chemosis (refers to lids and/or nictitating membranes):
0: No swelling
1: Any swelling above normal (includes nictitating membranes)
2: Obvious swelling with partial eversion of lids
3: Swelling with lids about half closed
4: Swelling with lids more than half closed

Discharge:
0: No discharge (may include small amounts observed in inner canthus of normal animals)
1: Any amount different from normal and/or lacrimation
2: Discharge with moistening of the lids and hairs just adjacent to lids
3: Discharge with moistening of the lids and hairs (considerable area around the eye)

Where standard lighting was considered inadequate for observing minor effects, eye examinations were performed using an ophthalmic examination lamp.
In cases of equivocal results when comparing the treated and untreated eyes, the illustrated guide from the Consumer Product Safety Commission, Washington, D.C. 20207 was used for additional control purposes.

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: Slight dulling of the normal luster of the cornea at 1 hour after instillation.

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: Slight dulling of the normal luster of the cornea at 1 hour after instillation.

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: Slight dulling of the normal luster of the cornea at 1 hour after instillation.

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 48 hrs

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 48 hrs

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #1

Time point:

24 h

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 72 hrs

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #1

Time point:

48 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #2

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not reversible

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #3

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not reversible

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

48 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 72 hrs

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritant / corrosive response data:

Instillation of approximately 89 mg of Single super phosphate (SSP) (a volume of approximately 0.1 mL) into one eye of each of three rabbits resulted in effects on the cornea, iris and conjunctivae.
Corneal injury consisted of slight dulling of the normal luster and had resolved within 24 hours in all animals. Iridial irritation grade 1 was observed in all animals and had resolved within 24 hours in one animal and within 48 hours in the other animals.
The irritation of the conjunctivae consisted of redness, chemosis and discharge. These findings had completely resolved within 72 hours in one animal, but remained present up to the end of the 21-day observation period in the other two animals, along with gray/white discolouration of the nictating membrane and/or lower eyelid (sign of necrosis).

Individual eye irritation scores are specified in the attached table.

Remnants of the test substance were present in the eye of all animals on Day 1.

No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Remarks:

Category 1 according to Regulalation (EC) No. 1272/2008

Conclusions:

- according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2007), Single super phosphate (SSP) should be classified as: having irreversible effects on the eyes (Category 1).

-according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures, Single super phosphate (SSP) should be classified as Irreversible effects on the eye (Category 1) and labeled as H318: Causes serious eye damage.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation

No reliable study with single superphosphate is present. In a reliable skin irritation study performed comparable to OECD 404 guideline, ammonium dihydrogenorthophosphate does show some effects on the erythema, which are minimal and fully reversible within 72 hours. In addition, a study with calcium bis(dihydrogenorthophosphate) is performed according to acceptable guideline (EU and US), showing no skin irritation. This was confirmed in supporting studies. Therefore, the substance is considered to be not irritating.

Eye irritation

In a reliable eye irritation study performed according to OECD 405 guideline, EC B.5, EPA and JMAFF guidelines, single superphosphate does show severe eye irritating effects. Instillation of approximately 89 mg of Single super phosphate (SSP) (a volume of approximately 0.1 mL) into one eye of each of three rabbits resulted in effects on the cornea, iris and conjunctivae.

Corneal injury consisted of slight dulling of the normal luster and had resolved within 24 hours in all animals. Iridial irritation grade 1 was observed in all animals and had resolved within 24 hours in one animal and within 48 hours in the other animals.

The irritation of the conjunctivae consisted of redness, chemosis and discharge. These findings had completely resolved within 72 hours in one animal, but remained present up to the end of the 21-day observation period in the other two animals, along with gray/white discolouration of the nictating membrane and/or lower eyelid (sign of necrosis). No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Justification for selection of skin irritation / corrosion endpoint:
Studies on the read-across substances ammonium dihydrogenorthophosphate and calcium (bisdihydrogenorthophosphate) are available. Since the studies were performed with substance analogues and the data are read across, the Klimisch score is 2.

Justification for selection of eye irritation endpoint:
One in vivo study on the substance is available.

Effects on eye irritation: corrosive

Justification for classification or non-classification

Based on the available data, single superphosphate does not have to be classified according to the CLP Regulation for skin irritation. However, classification for eye irritation is required: Cat. 1, Causes serious eye damage, H318.