INNSA Standard 6 - Stem Injection Requirements for Japanese Knotweed

  1. All operatives carrying out stem injection works will hold (or be directly supervised by someone holding) a valid NPTC PA1* certificate, as well as the relevant Award relating to the equipment being used (e.g. NPTC PA6**).
  2. INNSA Approved Companies offering invasive weed treatment should provide additional continued training to all site operatives. This training should provide specific information and techniques regarding all non-native invasive species which the site operatives will be required to treat.
  3. Where chemical application works are carried out in or near to water, a relevant Award (e.g. PA6W) must be held by a supervising member of the site team.
  4. Operations being carried out near water should apply for and comply with Environment Agency or SEPA Water Quality Management regulations.
  5. Chemical application works should always be carried out using appropriate PPE specific to the task in hand.
  6. Chemical application works should be carried out with a relevant policy in place to minimise the risks of cross-contamination, protect the environment minimise any risk to water.
  7. Companies should be forthcoming with customers about the risks of chemical treatments.
  8. Companies should always provide a written method statement, risk-assessment and COSHH assessment for all chemical application works that are undertaken
  9. Companies should abide by the recommended dosage rates as specified on the herbicide manufacturers’ guidelines.
  10. Companies should ensure that equipment is correctly calibrated priorwork commencing and maintained throughout the procedures.
  11. A management plan should be in place to ensure all works have been completed successfully.
  12. Surveying of the plants prior to contract must be completed by the contractor to establish the potential success of the stem injection in the first season.
  13. >Previously treated Japanese Knotweed, damaged or cut canes may take more than one season to treat and/or may need alternative remediation methods.
  14. >Sites with Giant Hogweed should have on-going monitoring programmes as viable seeds come germinate in future years within dormant seed banks.
  15. Companies should at all times maintain an awareness of current pesticide regulations and laws appropriate to their area(s) of operation and ensure all employees and/ sub-contractors are regularly updated preferably through CPD accreditation.
  16. Customers should be made aware that irrespective of the herbicide application method (Foliar/stem injection/ Leaf wipe) treatment areas even after herbicide application should be treated as contaminated. Ground disturbance or excavation work within the contaminated areas and buffer zones will need the contractors consent prior to works commencing and potentially additional remediation.


* Award in the Safe Use of Pesticides (QCF) Foundation Unit PA1,

** Award in the Safe Use of Pesticides (QCF) Unit PA6 Hand-Held Applicators


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