Another O2-scavenging technique involves sealing of a small coil of an ethyl cellulose containing a dissolved
photosensitive dye and a singlet O2-acceptor in the headspace of a transparent package. Due to illumination of with light of the appropriate wavelength, excited dye molecules sensitize O2-molecules, which have diused into the polymer, to the singlet state. These singlet O2-molecules react with acceptor molecules and are thereby consumed. The photochemical
process involved can be presented as follows