Sodium orthophenylphenate (SOPP) is used as a fungicide to control decay on apples and pears. It is a highly alkaline material, which is likely to cause injury if the fruits are exposed to it for several minutes or if the fruits are not rinsed with clear water after treatment. Particular care must be taken to prevent injury when SOPP is added to the soda ash solution that is used to float pears in flotation dumpers.
Overexposure of the fruits to SOPP causes a darkening at the lenticels and at breaks in the skin (see photo). Generally only the skin is affected, but in cases of severe injury the underlying flesh may be discolored to a depth of 1/4 inch.
This injury may be prevented by manually removing the fruits from the dump tank during equipment failures, and by rinsing the fruits with clear water after removal.
Pear sodium orthophenylphenate injury