The International Standards Organization (ISO, www.iso.org) is an NGO made up of national standards organizations representing 157 countries.
The American National Standards Institute (ANSI, www.ansi.org) is the US member body to ISO.
To follow the standards is voluntary unless called out in a treaty, law, or contract.
The guidance standard on Social Responsibility was published on November 2010 as ISO 26000 for voluntary use. It does not include requirements and is thus not a certification standard.