Maleic acid (CAS No.110-16-7, EC No.203-742-5, INCI: Maleic Acid) is an ingredient listed in the Cosing, with the function: Buffering.
The substance is not currently regulated by European Cosmetics Regulation 1223/2009.
It is listed in Annex VI/607-095-00-3 to European CLP Regulation 1272/2008, with the following classifications.
• Acute Tox. 4*, H302 - Harmful if swallowed.
• Eye Irrit. 2, H319 - Causes serious eye irritation.
• STOT SE 3, H335 - May cause respiratory irritation.
• Skin Irrit. 2, H315 - Causes skin irritation.
• Skin Sens. 1, H317 - May cause an allergic skin reaction.

Austria proposes to classify the substance as follows.

Identification
Index number
• 607-095-00-3
Chemical name
• maleic acid; (2Z)-but-2-enedioic acid
EC number
• 203-742-5
CAS number
• 110-16-7
Classification
Hazard class and Category code(s)
• Acute Tox. 4
• STOT SE 3
• Skin Corr. 1B
• Eye Dam. 1
• Skin Sens. 1
Hazard statement code(s)
• H302 - Harmful if swallowed.
• H335 - May cause respiratory irritation.
• H314 - Causes severe skin burns and eye damage.
• H318 - Causes serious eye damage.
• H317 - May cause an allergic skin …