What is the lowest probable toxic dose of fluoride for a child weighing 20 kilograms?

The lowest probable toxic dose of fluoride for a child is crucial to understand, especially regarding the safety and administration of fluoride treatments. For children, the toxic dose is typically estimated to be around 5 mg of fluoride per kilogram of body weight. Therefore, for a child weighing 20 kilograms, this calculation would suggest that a toxic dose could begin at around 100 mg of fluoride (5 mg/kg x 20 kg = 100 mg).

This threshold is based on established clinical guidelines and observations regarding fluoride toxicity. It indicates that doses at or above this level can pose health risks, including acute toxicity symptoms. Understanding this dose helps in preventing potential overuse of fluoride in dental treatments or products for children, ensuring their safety while promoting oral health effectively.

The other options present levels of fluoride that exceed the calculated toxic dose for a child of this weight, leading to greater risks of adverse effects. Such knowledge is essential for dental professionals when recommending fluoride use tailored to a child's specific circumstances.