Is 1,1-Cyclobutanedicarboxylic acid (CAS: 5445-51-2) safe?

1,1-Cyclobutanedicarboxylic acid (CAS: 5445-51-2) is generally considered safe when handled properly, but it may cause skin or eye irritation. Safety data sheets (SDS) recommend using appropriate protective equipment, such as gloves and goggles, and avoiding inhalation or contact with skin. It is classified as a low-toxicity compound under standard exposure conditions, though long-term effects require further study.