Garic, which manufactures, hires and sells welfare and environmental equipment to the construction industry, has a fleet of 50 vehicles.
It became a bronze member after learning about the scheme while working on Crossrail.
Garic transport manager Mark Booth said: “Receiving Fors gold is a fantastic achievement and reflects the level of professionalism and commitment of our in-house transport operations.
“There are very few competitors within our industry that have this level of recognition and we’ll be proud to display the Fors gold logo on our fleet.”
Fors operations manager Sonia Hayward said: “We congratulate Garic on this crucial milestone for the business which acknowledges the hard work of the whole team to raise standards and implement best practice.
“Achieving our 200th Fors gold member is a significant milestone for us, and we are delighted that companies such as Garic continue to see measurable improvement in their operations when progressing to Fors gold accreditation.”