Another factor that can cause this is excess moisture, which can accelerate deterioration of nitrocellulose with the presence of nitrate groups, either newly fragmented from heat or still trapped as a free acid from production. Both of these sources allow the accumulation of nitric acid, a main component of acid rain that leads to corrosion of the environment. Another form of deterioration, Photochemical, is severe in celluloid because it absorbs ultraviolet light well. The absorbed light leads to chain-breakage and stiffening