The search did not return relevant information specifically about "grand nails" and "spa product" details, positive or negative ingredients or materials. Therefore, I will answer the question based on existing knowledge. When it comes to nail and spa products, it's important to be mindful of the ingredients used. Some common harmful ingredients found in beauty and personal care products include formaldehyde, toluene, and dibutyl phthalate. These chemicals have been associated with various health concerns, so it's advisable to look for products that are free from these harmful substances. On the positive side, many nail and spa products now feature safer and more natural ingredients, such as plant-based oils, fruit extracts, and water-based formulas. These ingredients can provide nourishment and care for the nails and skin without the use of harsh chemicals. When choosing nail and spa products, it's a good practice to carefully review the ingredient list and opt for products that prioritize safety and transparency. Additionally, seeking out brands that are committed to using sustainable and earth-friendly ingredients can further support a healthier and more environmentally conscious beauty routine.