Registration Dossier

Administrative data

Description of key information

Irritation/Corrosion

The registered substance 1-phenyl-3-methyl-5-pyrazolone is classified as non-irritant substance according REACh and CLP regulation based on In vivo skin irritation study results.

Eye irritation

The registered substance 1-phenyl-3-methyl-5-pyrazolone is classified as non-irritant substance according REACh and CLP regulation based on In vivo eye irritation study results.

Key value for chemical safety assessment

Eye irritation

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

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Eye irritation :

The key study (OECD Guideline 405, 100mg of pure substance, GLP, Klimisch 2) is an Eye Irritation Test on New Zelands rabbits. Three rabbits were exposed to 100g of pure 1-phenyl-3-methyl-5-pyrazolone through eye instillation into conjunctival sac on the left eye. The treatment period was 24 hours, no rinsing was made. Ocular reactions were observed and scored as cornea ulceration, conjunctivae redness, iris hemorrahge or discharge compared to the untreated right eye at different time points : 1, 24, 48 and 72 hours post-treatment. Treatment with registered item did not induce ocular reactions.

Two others studies were availables to determine the potential eye irritation of the substance. Nevertheless, these studies reports datas from Bovine Corneal Opacity and Permability Test (BCOP) and Hen's Egg Test ChorioAllantoïc Membrane (HET CAM), which were not sufficient to etablish a classification below the category 1A as irritant according REACh and CLP regulations.

Irritation/Corrosion

Clouzeau, 1992 :

The test available (OECD Guideline 404, GLP, Klimish 2) is a in vivo skin irritation test in which rabbits were exposed to 0.5ml of 1% of the substance diluted. However, this concentration of 1% is not suitable to assess irritation/corrosion properties of the pure substance, as recommended in REACh regulation. The results of the study showed mild transcient irritation.

Leist, 1980:

The hair in the dorsal region of the body of 6 rabbits was remoced with an electric clipper over an area of about 3x 6  cm. One half of the clipped skin was in addition scarified with a scarificator. Each animal was treated with 500 mg of 1-Phenyl-3-methyl-5-pyrazolon pasted with 0.35 ml physiologic saline solution. The substance was evenly distributed over the whole surface of 2.3 x 2.5 cm cellulose patch on a piece of surgical plaster (Hansamed(R)). The plaster was fixed to the prepared skin area and covered with a indifferent, impermeable polyethylene film (6-8cm wide). Finally the animals body was fixed with an elastic bandage. The exposure period was 4 hours. A first examination took place immediately after removal of the patches. Further examination tool place after 48 and 72 hours post application. After application of the substance (pasty form) an irritation index score of 1.5 was determined. Due to classification according to the FDA guideline mentionned in the report, the substance was therefore to be described as slighty irritant. under CLP regulation, the obtained score of 1.5 did not led to a EU-CLP classification. Hence, the test article was not classified for Skin Irritation.

The identity of the test substance was not sufficiently documented. Only a summary test report was available, there was no raw data. However, the study was conducted under FDA test protocols. Appropriate dose level was used. The scoring system deviated slighty from the current OECD protocol. Control analysis was performed. Restriction for reliability was due to the age of the study (1980). However, this study was considered as relevant.

Sire, 2004 : in a skin sensitisation study (LLNA -Klimisch 1) where the substance was applied for 6 day up to 25%, on the mouse ear, no irritant effects were observed and confirm the non irritant properties of the substance.

Justification for classification or non-classification

Eye irritation

Based on the result of the key study for skin irritation, the registered substance 1-phenyl-3-mehtyl-5-pyrazolone is classified as non-irritant for eyes according CLP and REACh regulation.

Irritation/Corrosion

Based on the results of two availables studies on skin irritation, and data available for skin sensitisation and according to the CLP criteria, the test article 1 -phenyl-3 -methyl-5-pyrazolone was not classififed for skin irritation.