Google’s six data centers on US soil have been successfully audited for systematic efforts to diminish their impact on the environment and for being safe and healthy work environments.

Joe Kava, senior director of data center construction and operations at Google, wrote in a blog post that Google was the first “major internet services company” go get third-party certifications like these for all of its data centers.

“For the last year, our data center team has been working on a project to bring our facilities to even higher standards for environmental management and workforce safety,” Kava wrote. “Recently we got the good news that our work paid off.”

The data centers that have been certified are located in The Dalles, Oregon, Council Bluffs, Iowa, Mayes County, Oklahoma, Lenoir, North Carolina, Monck’s Corner, South Carolina, and Douglas County, Georgia.

The ISO 14001 certification from the International Organization for Standardization is recognition that a company has a systematic approach to improving its environmental performance and follows it.

Google, for example, minimized the run-time and need for maintenance of back-up generators at its US data centers, therefore minimizing their impact on the environment. The company also worked with oil and generator manufacturers to extend the lifetime between oil changes, reducing oil consumption by generators by 67%, Kava wrote.

Another feature that earned Google ISO points was the process the company implemented for handling, packaging, shipping and recycling batteries used for power back-up on each server in its data centers.

The workplace health and safety certification is OHSAS 1800. It is a British standard for health and safety management systems in the workplace.