Essential oils can be potent and may cause respiratory irritation in infants. The developing lungs of a baby are more sensitive, and exposure to certain oils might lead to adverse reactions such as allergic responses or respiratory issues. It's also important to consider the concentration of the oils being used, as high concentrations can be harmful.

Additionally, not all essential oils are safe for babies, and some can be toxic. Oils such as eucalyptus and peppermint should be avoided entirely, while others may only be used sparingly and with guidance. If you choose to use a diffuser, ensure the area is well-ventilated and monitor the baby closely for any signs of discomfort.