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Administrative data

Description of key information

No reliable skin irritation study with triple 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 was confirmed with a reliable skin irritation study with calcium bis(dihydrogenorthophosphate). Based upon a reliable in vivo eye irritation study with triple superphosphate, the substance is considered an eye irritant.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation
Remarks:
no data
Type of information:
not specified
Adequacy of study:
other information
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: data not retrieved; secondary source
Reason / purpose for cross-reference:
reference to same study
Guideline:
other: not mentioned
Principles of method if other than guideline:
no data
GLP compliance:
not specified
Strain:
not specified
Vehicle:
not specified
Controls:
not specified
Duration of treatment / exposure:
no data
Observation period (in vivo):
no data
Number of animals or in vitro replicates:
no data

mild irritation

Conclusions:
mild irritant
Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Data on skin irritation/corrosion of triple superphosphate is not available. The assessment of skin irritation/corrosion was therefore based on studies conducted with reference substances as part of a read across approach, which is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. Structural similarities and similarities in properties and/or activities of the source and target substance are the basis of read-across. A detailed justification for the read-across approach is provided in the technical dossier (see IUCLID Section 13) and within Chapter 5.1 of the CSR.

Skin irritation

No reliable study with triple 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 reliable study with calcium bis(dihydrogenorthophosphate) is available, performed according to the relevant guidelines (EU and US), and the substance was not irritating. This was confirmed in supporting studies.

Eye irritation

In a reliable eye irritation study performed according to OECD 405 guideline, EC B.5, EPA and JMAFF guidelines, triple superphosphate does show serious eye damaging effects. Instillation of approximately 69 mg of Superphosphate, concd. (TSP powder) (a volume of approximately 0.1 mL) into one eye of each of three rabbits resulted in effects on the cornea, iris and/or conjunctivae. Corneal injury was observed in one animal behind the lower eyelid and consisted of opacity (maximum grade 3) and epithelial damage (maximum 25% of the corneal area). As a result of the corneal injury, pannus (neovascularization of the cornea) was apparent 14 and 21 days after instillation. In this same animal irritation of the conjunctivae (consisting of redness, chemosis and discharge) remained present up to the end of the 21-day observation period, along with gray/white discolouration of the nictating membrane and lower eyelid (sign of necrosis). Reduced elasticity of both eyelids was also observed for this animal. Irritation of the conjunctivae among the other two animals also consisted of redness, chemosis and discharge, and had completely resolved within 7 or 14 days. Iridial irritation grade 1 was observed in two animals and had resolved within 24 or 72 hours. 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:

Hazard assessment is conducted by means of read-across based on a category approach. All available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties between the source and target substances and overall quality assessment (refer to the endpoint discussion for further details).

Justification for selection of eye irritation endpoint:

The reliable GLP compliant  OECD Guideline study was chosen.

Effects on eye irritation: corrosive

Justification for classification or non-classification

Based on the available data, triple superphosphate does not have to be classified according to Directive 67/548/EC and the CLP Regulation for skin irritation. However, classification for eye irritation is required: according to CLP Regulation Cat. 1, Causes serious eye damage, H318, and according to Directive 6/548/EC it should be classified as irritant, Xi, and Risk of serious damage to eyes, R41.

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