Was it appropriate to classify 18-year-olds as children in a head lice study?

[ThisNavyAnt]

Would you agree that it was inappropriate for this head lice study (link below) that applied Ovide to the scalps of children to comtrol head lice considered 18-year-olds as children representative of likely prescribed child Ovide use for lice?

https://nepis.epa.gov/Exe/ZyPDF.cgi/P10051KW.PDF?Dockey=P10051KW.PDF

I will not be reading a 202 page study but I would imagine the lice are much the same regardless of the age of the head.

18 year olds aren’t children by definition in the UK, I don’t know about other countries, but they also tested on 9 year olds and 3 year olds so I don’t see much of a problem.