ISO 9001 requires organisations to demonstrate that have a quality management system in place to ensure consistency and improvement leading to high levels of performance and customer satisfaction.
They are assessed annually to ensure progress is being maintained.
ISO 14001:2004 centres around environmental policy and a company's action plan to manage its impact on the environment.
Green-tech said it has a strong environmental focus and always tries to source products that are manufactured from sustainable sources and are recyclable.
Managing director Rachel Kay said: "We are particularly pleased to have retained these standards as it underlines our commitment to our customers and our focus on quality.
Our customers have continued assurance and confidence that they are dealing with a reliable business partner, delivering high quality products and an excellent level of service in a controlled and consistent manner."