I do not know what the sbf is here, but it had a pretty good test yesterday for us. Spent the day at Great America in Chicago in 95 degree heat, no sunburn, and a pretty good tan for all of us. Made recipe as posted and transfeered it to a spray/lotion bottle. Applied at 10 am and reapplied at about 2-3 pm. Really worked well, seemed as though the fragrance chased away the gnats/mosquitos too, as the gnats were pretty bad, but seemed to stay away from us. Going to get HOT this weekend so definately will try again, as work in the yard, and hit the beach here. Made for New Zaar Tag..