Which agency determined that Methyl Methacrylate Monomer should not be used in acrylic monomers?

The correct choice is the FDA, which stands for the Food and Drug Administration. The FDA is responsible for ensuring that food, drugs, cosmetics, and medical devices are safe and effective for consumers. In the context of nail technology, the FDA has taken a stance against the use of Methyl Methacrylate Monomer (MMA) in acrylic nails due to health concerns.

MMA can cause significant allergic reactions and skin irritation in some individuals. It can also lead to adverse effects on the nails and surrounding skin, including potential long-term damage. The FDA's guidance aims to protect both consumers and professionals in the nail industry by promoting the use of safer alternatives.

While other agencies like OSHA (Occupational Safety and Health Administration) focus on workplace safety, and the CDC (Centers for Disease Control and Prevention) addresses public health issues, it is the FDA that specifically regulates substances used in cosmetic products, making it the relevant authority regarding the restriction of MMA in acrylics.

NIMH (National Institute of Mental Health) deals primarily with mental health research and issues, which is outside the scope of nail technology and chemical safety regulations.