As if to set the tone for the year, in the first week of January Cargill made a critical choice: It would no longer conduct business with a palm oil supplier in Guatemala.

The business, it said, had failed to meet the corporation's sustainability goals. Cargill wanted to reach a 100% transparent palm oil supply chain by 2020. In fact, it had pledged to do so before the United Nations in 2014, and partnered with The Forest Trust to help. But one weak link could break its promise.

Cargill's story is not uncommon. As corporate social responsibility evolves from charitable promises to a sales and operations goal, companies are having to revisit not just their sourcing practices, but also their standards.

And if ethical sourcing hit the spotlight in 2018, it is because the procurement world saw a shift in how these terms were defined. A big question to answer was: Who gets to define and certify ethical sourcing?

Here are six stories showing the trend in action over the course of the year.

1. Cargill cuts ties with palm oil supplier over sustainability concerns

   Guatemalan palm oil supplier REPSA faces allegations of environmental and human rights violations. Read More >>

2. Fashion brands face petition for supply chain transparency, but at what cost?

   Forever 21, Armani and Walmart received a petition for more transparency from 70,000 consumers this week, but the need to maintain a competitive advantage could complicate the brands' efforts. Read More >>

3. Report: Companies' sustainability efforts limited by lack of oversight

   A Stanford University study found companies faced difficulty in monitoring sustainability past their Tier 1 suppliers. Read More >>

4. Palm oil group suspends Nestlé, but is the company guilty?

   Nestlé failed to meet some certification requirements for the Roundtable on Sustainable Palm Oil, then wrote a letter raising questions over its value. Read More >>

5. Mars will invest $1B to fix 'broken' cocoa supply chain

   The manufacturer will work directly with farmers and use GPS mapping in an effort to remedy pervasive issues in the cocoa industry. Read More >>

6. As companies change sourcing standards, Fairtrade steps in to help

   Many procurement professionals are bringing certifications in-house, pushing the Fairtrade Foundation to adapt accordingly. Read More >>