Appendices

APPENDIX A: SUSTAINABILITY REPORTING AT COMPASS MINERALS

This report is our third public sustainability disclosure document using the Global Reporting Initiative™ Sustainability Reporting Standards (GRI Standards). New in this report are a set of sustainability targets, which we expect to continue to update in our future reports.

Transition to the GRI Standards

In 2012, we began to align our systems, data tracking mechanisms and strategic intent toward expanding the use of the GRI Framework. This internationally recognized framework provides a comprehensive, standardized process for evaluating the impacts of our business activities across our value chain. It also enables us to share Compass Minerals’ positive contributions and areas where we’re doing well. At the same time, and perhaps more importantly, the process deepens our understanding of sustainable development and helps identify opportunities for improvement related to environmental impacts, economic results and social impact, including human resource practices and community relations.

The 2014 calendar year report, Taking Care of the Essentials (published in July 2015), was prepared as a GRI G4 Core “In Accordance” Report. It established 2013 as the baseline for performance indicators from which we set targets and gauge progress. In 2016, we published an update on progress made in 2015.

For this reporting cycle, we have transitioned to the GRI Standards. Learn about our reporting process, including stakeholder engagement and materiality assessment efforts, and improvements we implemented in Appendix B.

About Our Data

Any dollar amounts listed within the report are in U.S. dollars.

There are inherent limitations to the accuracy of environmental and social data. We recognize that our data will be affected by these limitations and continue to improve data integrity by strengthening our internal controls. Data in this report is collected from third-party sources, surveys with internal and external stakeholders and other internal sources as indicated. We have not independently verified any of the data from third-party sources. Unless otherwise noted, Produquímica and its subsidiaries, which we acquired in October 2016, are not included in this report.

Environmental data in this report pertains to our direct emissions unless otherwise stated. We report in this way, in line with industry practice, because these are the data we can directly manage and affect through operational improvements. We only include data in this report that were confirmed by 2017. If incidents are reclassified or confirmed, or if significant data changes occur after preparation of this report, they will be updated in the following year’s publication. The accuracy of environmental and social data may be lower than that of data obtained through our financial systems.

The information discussed in this report contains statements regarding future sustainability measures, targets and other goals. These goals are disclosed in the limited context of our sustainability efforts and should not be understood to be statements of management's expectations or estimates of financial results or other guidance. We specifically caution investors not to apply these statements to other contexts.

DeepStore, Protassium+ and Wolf Trax are trademarks of Compass Minerals International, Inc. or our subsidiaries in the U.S. and other countries.

The 2016 report has been prepared in accordance with the GRI Standards: Core option. For more information, refer to the GRI Content Index.

Move to Web-based Reporting

We are excited to make the shift to web-based reporting. Sharing our sustainability progress online offers several benefits. We can more efficiently publish updates on our performance metrics on an annual basis while adding updates on the company, our strategy and management approaches, as well as sharing stories and case studies as needed.

We welcome your feedback: Please send comments and questions to Sustainability@compassminerals.com.

Appendix B: THE PROCESS — MATERIALITY & STAKEHOLDER ENGAGEMENT

Stakeholder Engagement

We value the views and interests of all of our stakeholders regarding sustainability issues. We define “stakeholders” as those who are impacted by our operations and products, along with those who have an interest in, or can influence, how we manage our businesses.

Ways We Engage

We identify stakeholder groups across the value chain and assess stakeholder relationships (responsibility, dependency, influence and proximity) to understand needs and inform level and methods of engagement. Approaches to engagement vary based on stakeholder group and range from informal conversations to surveys, meetings and events.

The following table summarizes key stakeholder groups and the ways and frequency in which we engage with stakeholders. In addition, written communications such as press releases, annual and sustainability reports, and our corporate website provide ways to share information broadly with multiple stakeholder groups.

Ways We Engage

*These stakeholder groups are also involved in our report-specific engagement activities, described in the Defining Report Content section.

Organizational Memberships and Affiliations

Active involvement with a range of associations and organizations reflects our collaborative approach and the value of collective action for shared objectives. This involvement helps strengthen relationships, promote research and knowledge sharing, and support the advancement of best management practices. Level of engagement includes general involvement, formal membership and governance roles.

Organizational Memberships and Affiliations

Defining Report Content

Each reporting cycle presents opportunities for improvement. For the 2016 reporting cycle, we built on progress from previous years by implementing a more strategic and process-based approach to managing sustainability issues and reporting. This includes our approach to identifying material topics.

Though we invited a range of relevant internal and external stakeholder groups to participate in the materiality process described below, we directed increased attention on our workforce in the U.S., Canada and the U.K. (Brazil was excluded in this cycle due to onboarding activities), customers, shareholders and community representatives.

Materiality Assessment Process

Below is a description of our process for implementing the GRI reporting principles for defining report content. The approach Compass Minerals took to identify material topics is stakeholder-informed – meaning stakeholder input is evaluated and prioritized to help shape our non-financial reporting efforts. This process identified the key topics or concerns of our stakeholders. Topics of greatest concern as identified directly from the engagement survey were related to governance and business practices, product and service responsibility, occupational health and safety and environmental compliance. Less than 10 percent of respondents provided open-ended input for each topic area. These direct comments have been shared with the company’s senior leadership.

Materiality Assessment Process

Materiality Matrix

The materiality matrix below charts Compass Minerals’ significant direct or indirect economic, environmental and social impacts against those that have been identified by our stakeholder as relevant through our materiality assessment process.

Threshold 1: On or above radius of 3.5
Threshold 2: Beyond radius of 4
*Reflects the top 10 in ranking of top 5 selected topics

Material Topics

The following table lists the topics selected for inclusion in the report along with a brief description of where the impacts occur. Our ability to fully manage and control outcomes within any issue area is based on whether the impacts occur inside or outside our organizational control.

Material Topics

Appendix C: EXTERNAL ASSURANCE STATEMENT

iCompli External Assurance Statement

In an effort to provide transparency and make certain the data we have provided in this report is correct and in keeping with general environmental data standards, we sought independent third party assurance using the ISO14064-3 standard for the following metrics for 2017 from iCompli Sustainability.

• Scope 1 GHG emissions (Global Reporting Initiative Indicator 305-1)
• Scope 2 GHG emissions (Global Reporting Initiative Indicator 305-2)
• Energy consumption (Global Reporting Initiative Indicator 302)
• Water withdrawal by source (Global Reporting Initiative Indicator 303)
• Scope 3 GHG emissions (Global Reporting Initiative indicator 305-3) from upstream transportation and distribution, and downstream transportation and distribution

Please find their verification statements here.

Appendix D: NON-GAAP RECONCILIATION

Non-GAAP Reconciliation (in millions)

¹ Primarily includes additional expense recognized from the sale of finished goods inventory, which had its cost basis increased to fair value as a result of the acquisition of Produquímica.