| All operations were carried out on ice under a dim green safe light to prevent photodegradation, isomerization and structural changes of the pigments. |
| The photodegradation which considerably speed up the visible skin ageing increases also a lot the risk of development of cutaneous neoplasm. |
| However, the mechanism of porphyrin photodegradation can be complex and differs in solution and in biological media. |
| Alpha-HCH is, in principle, degradable in environmental compartments by abiotic processes such as photodegradation or hydrolysis. |
| It appears generally that hydroxylated indoles undergo photodegradation more readily than nonhydroxylated derivatives. |
| Even when indirect photolysis could occur with a photosensitizing agent, there is no clear evidence of lindane photodegradation. |
