That depends on your definition of "harmful". Many ingredients are harmful in ways that common folks are not aware of. I'll break it down for you. In this case, the ingredients are: Triclosan, Disodium Cacoamphodiacetate, Sodium Trideceth Sulfates, Propylene Glycol, Citric Acid, Phenoxyethanol, Purified water
Triclosan is the antibacterial agent, and has recently been the cause of some debate in the medical community, but not because of it's toxicity to humans. However, extended and unnecessary use of this chemical can cause swift resistance in bacteria, leading to the dreaded "superbugs". When your normal skin bacterial, such as
Staphylococcus epidermidis, become resistant to antibiotics, problems happen.
Disodium Cacoamphodiacetate and Sodium Trideceth Sulfate are synthetic surfactants (soap, if you will) made from coconut oil. Such surfactants, when washed into the ocean, are causing something known as "ecological death" of schooling fishes and other organisms that rely on chemical communication. If you want more information about this, message me.
Propylene Glycol is a solvent, used to dissolve the other ingredients. This is toxic to cats in small doses, but only toxic to humans (and dogs) in very large doses. Some people are allergic to it. When this chemical is washed into water sources, bacteria that break it down use so much oxygen that the water becomes anoxic, killing other organisms.
Citric Acid is, in this case, a preservative. I wouldn't worry about it, really.
Phenoxyethanol is used to dissolve hydrophobic chemicals, a preservative and as a bacteriacide. My comments above, for Triclosan, apply here. However, it has come into frequent use only fairly recently (the previous chemical released formaldehyde, this does not!) and the effects of long-term exposure are, as yet, unknown.
Hope this helps!