Which of the following is an indicator that an MMA-containing product is present?

• A. Nail enhancement is very hard and inflexible
• B. Strong odour
• C. It dissolves easily in acetone
• D. It is safe to file nails

Answer: (A)

The key idea here is recognizing the distinctive physical property of MMA-based nail products. When a product contains methyl methacrylate, the cured enhancement tends to become extremely hard and inflexible. That rigidity means the layer won’t bend or flex with the natural nail as EMA-based systems do, making the enhancement feel unusually stiff. This is a noticeable, practical sign technicians look for, because it also helps explain why MMA-based enhancements are so difficult to file or remove and can cause damage if forced.

Odour can be strong with many products, so it isn’t a definitive clue. The idea that it dissolves easily in acetone isn’t correct for MMA (MMA resins resist acetone, whereas EMA-based products solubilize more readily). And saying it’s safe to file nails isn’t reliable, since the extreme hardness of MMA can actually make filing risky or impractical. So the clearest tell among these options is the very hard and inflexible nature of the enhancement, which points to MMA being present.