The first combined DQS Certificate in the fields of quality, environment, occupational health & safety awarded to GL Group. The GL Group has received a combined certificate of compliance with the BS OHSAS 18001, ISO 9001 and ISO 14001 standards after successfully passing an integrated management system audit conducted by the German certification body DQS. The Group is the first technical advisor for assurance, consulting, classification and certification to receive such a combined matrix certificate. head office in Hamburg. makes it safer, smarter and greener.