No timer interval error may exceed what percentage of the maximum timer interval?

The correct answer is that no timer interval error may exceed 10 percent of the maximum timer interval. This regulation is established to ensure the safe and effective operation of tanning equipment. A timer error that exceeds 10 percent could lead to overexposure to UV radiation, which poses a significant health risk to clients, including skin burns and increased likelihood of skin cancer. The 10 percent limit helps maintain strict safety standards, ensuring equipment is calibrated properly and users are protected from potential harm. By adhering to this standard, tanning facilities can ensure they are compliant with health and safety regulations, fostering a safer environment for their clients.