What is the ruling on using hair spray? Does it break the fast in Ramadan? And does it invalidate Wudu'?

Using hairspray is permissible as long as it does not contain impure, forbidden, or harmful substances. It does not affect fasting. It does not invalidate ablution if applied after it. However, if applied before ablution and it forms an insulating layer that prevents water from reaching the hair, then it invalidates the ablution, because wiping the head is an obligation, as Allah Almighty says: "and wipe over your heads."