As with lotion sunscreens, choose sticks and sprays that are broad-spectrum, water-resistant and have an SPF (sun-protection factor) of 30 or higher.
For all types of sunscreen, make sure you reapply it every two hours when outdoors or immediately after swimming or sweating.
When using sticks, apply four passes back and forth on each area of skin to ensure ample protection. Then, rub the sunscreen in so there is an even layer of coverage.
When using sprays, hold the nozzle close to the skin and apply generously. A good rule of thumb is to spray until the skin glistens. Rub the spray in thoroughly to ensure there are no uncovered spots and coverage is even.
Never spray sunscreen near your face or mouth and do not inhale it. Spray your hands first and then use them to apply sunscreen to your face.
Don’t use spray sunscreen on windy days because it’s harder to apply and there’s a greater chance of accidentally inhaling it. Never apply a spray sunscreen near heat or an open flame, or while smoking, and make sure it’s thoroughly rubbed in and dry before going near open flames.
American Academy of Dermatology