Non-UV resistant syringe usage would be viewed as a dispensing failing by leading resin manufacturers.The cleaning of single use syringes and needles is almost impossible, time consuming and unlikely to be strictly undertaken in the field by repair technicians after every dose. 

Resin manufacturers recommend cleaning resin residue using isopropyl alcohol not blue paper towel.

Its as basic as that! If you are told you have the best windscreen repair kit on the market and you are using syringes which are not UV protected this means the resin is starting to cure before you have even put it in the chip.

GT Smart-leading the way. Check this posts date and see the others follow as a good idea!