photochemical

adj

1. (not-comparable)Of, relating to, or produced by photochemistry or by photochemical reactions.

   “The O–O bond in benzoyl peroxide and the C–N bonds in AIBN homolyze under thermal or photochemical conditions.”

noun

1. Any chemical compound (such as silver halides) used in photography.

   “[…] Kodak's production of photochemicals, and Sheppard worked out a method of suspending pulverized coal in fuel oil for use in U.S. Navy ships. By the spring of 1918 Sheppard had developed a collodial mixture containing chemical […]”

   “Troubleshooting emulsion artifacts: Many problems will be averted by consulting Kodak materials and Reference 4 before the first experiment. Because nuclear track emulsions are very sensitive to chemical contaminants, especially metals and photochemicals, Kodak recommends three controls for every experiment: blank, charged slides (no tissue), charged slides with unlabeled tissues (not hybridized), and charged slides with hybridized (radioactive) tissue sections.”