Fever-Tree

This company has sustainability claims on its website under the headings carbon footprint, packaging, biodiversity, malaria no more, supply chain, and engagement & inclusivity.
Source: company website (2021)

This company has products that have been verified as compliant with the Non-GMO Project Standard, North America's only independent verification for products made according to best practices for GMO avoidance.
Source: Non-GMO Project (2021)

California, the UK and Australia have all enacted legislation requiring companies operating within their borders to disclose their efforts to eradicate modern slavery from their operations and supply chains. Follow the link to see this company's disclosure statement.
Source: company website (2020)