If you need to get rid of weeds, then you need someone with the correct qualifications and skills to do the job safely.
I hold the City & Guilds NPTC Level 2 Award in the Safe Use Of Pesticides (PA1 and PA6).
The PA1 foundation unit is a theory based course and covers the legislation, health and safety requirements, precautions, product label information and safe handling and use of pesticide application. The PA6A practical unit covers the handling and safe use of pesticides using knapsack sprayers.