When sourcing for infants and children, the chemical composition is the most critical factor. DEET is effective but should be used in concentrations below 10-30% depending on age; however, many B2B buyers now prefer Picaridin (Icaridin) or IR3535 as they are less irritating and odorless. For the 'natural' market, look for Oil of Lemon Eucalyptus (OLE) or Citriodiol, but ensure the supplier specifies these are not for children under 3 years old. Always verify that the formula is alcohol-free and paraben-free to prevent skin irritation.