UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Commission file number 001-32597

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act. (Check one):

The aggregate market value of the registrant's common stock held by non-affiliates was $14,966,659,383$5,597,334,751 based on the closing sale price of common stock on June 30, 2015.2016.

233,082,556233,114,691 shares of the registrant's common stock, $0.01 par value per share, were outstanding as of January 29, 2016.31, 2017.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant's definitive proxy statement for its 20162017 annual meeting of stockholders (Proxy Statement) are incorporated herein by reference into Part III of this Annual Report on Form 10-K. The Proxy Statement will be filed with the Securities and Exchange Commission, pursuant to Regulation 14A, not later than 120 days after the end of the 20152016 fiscal year, or, if we do not file the proxy statementProxy Statement within such 120-day period, we will amend this Annual Report on Form 10-K to include the information required under Part III hereof not later than the end of such 120-day period.

CF INDUSTRIES HOLDINGS, INC.

We are the largest nitrogen fertilizer producer in North America. Our primary nitrogen fertilizer products are ammonia, granular urea, UAN and AN. Our historical sales of nitrogen fertilizer products from our Nitrogen Product Segments are shown in the following table. Net sales do not reflect amounts used internally, such as ammonia, in the manufacture of other products.

Our historical sales of phosphate fertilizer products are shown in the table below.

Historically, selling prices for our products have fluctuated in response to periodic changes in supply and demand conditions. Demand is affected by planted acreage, crop selection and fertilizer application rates, driven by population growth, changes in dietary habits and non-food usage of crops, such as the production of ethanol and other biofuels, among other things. Supply is affected by available capacity and operating rates, raw material costs and availability, government policies and global trade.

Periods of strong demand, high capacity utilization and increasing operating margins tend to stimulate global investment in production capacity. The construction of new nitrogen fertilizer manufacturing capacity in the industry, plus improvements to increase output from the existing production assets, increase nitrogen supply and affect the supply and demand balance. In recent years, fertilizer producers, including CF Holdings, have built new production facilities or expanded capacity of existing production assets, or announced plans to do so. In the current environment, global nitrogen fertilizer supply has increased faster than global nitrogen fertilizer demand, creating a global nitrogen fertilizer oversupply leading to lower nitrogen fertilizer selling prices. Lower global production costs driven by lower feedstock costs and foreign exchange rate changes, and reduced ocean freight costs, have further contributed to the tax lawslower priced environment.

Additional production capacity is expected to come on line over the next twelve months. We cannot predict the extent to which the current oversupply environment, global or relevant factslocal economic and financial conditions or changes in such conditions, or other factors may jeopardizecause delays, cancellation or delayacceleration of other announced and/or ongoing projects.

We expect the proposedlower priced environment to continue until global supply and demand become more balanced through a combination withof continued demand growth and supply reductions as producers respond to lower realized margins by taking higher cost production facilities off line.

During periods of industry oversupply, our financial condition, results of operations and cash flows tend to be affected negatively as the ENA Business of OCI.

We are subject to intense price competition from our competitors. Most fertilizers are global commodities, with little or no product differentiation, and customers make their purchasing decisions principally on the basis of delivered price and to a condition that there shalllesser extent on customer service and product quality.

We compete with many producers, including state-owned and government-subsidized entities. Consolidation in the industry has increased, and future consolidation is expected to further increase, the resources of several of our competitors. For example, in September 2016, our competitors Agrium Inc. and Potash Corporation of Saskatchewan Inc. announced plans to merge. Some of our competitors have been no (i) changegreater total resources and are less dependent on earnings from fertilizer sales, which make them less vulnerable to industry downturns and better positioned to pursue new expansion and development opportunities. Furthermore, certain governments as owners of some of our competitors may be willing to accept lower prices and profitability on their products in law, official interpretation thereof,order to support domestic employment or officially proposed action byother political or social goals. Our competitive position could suffer to the U.S. Internal Revenue Service (IRS)extent we are not able to expand our own resources, either through investments in new or existing operations or through acquisitions, joint ventures or partnerships.

China, the U.S. Departmentworld’s largest producer and consumer of nitrogen fertilizers, currently has significant capacity surplus and many high-cost plants. As a result, the domestic nitrogen industry in China is operating at low rates. If Chinese government policy, devaluation of the Treasury,Chinese renminbi or decreases in Chinese producers’ underlying costs such as the price of Chinese coal encourage increased production capacity utilization, any resulting export volume could adversely affect the balance

We also face competition from other than those rules describedfertilizer producers in Notice 2015-79 issued by the Department of the TreasuryMiddle East, Europe and IRSLatin America, who, depending on November 19, 2015, (whether or not yet approved or effective)market conditions, fluctuating input prices, geographic location and freight economics, may take actions at times with respect to subject matters coveredprice or selling volumes that adversely affect our business, financial condition, results of operations and cash flows.

Conditions in U.S., European and other global agriculture areas significantly impact our operating results. Agricultural planted areas and production can be affected by Code Section 7874a number of factors, including weather patterns and field conditions, current and projected grain inventories and prices, demand for agricultural products and governmental policies regarding trade in agricultural products. These factors are outside of our control.

Governmental policies, including farm and biofuel subsidies and commodity support programs, as well as the prices of fertilizer products, may also directly or (ii) passageindirectly influence the number of any bill that would implement a change in applicable laws by eitheracres planted, the U.S. Housemix of Representatives orcrops planted and the U.S. Senate with respect to subject matters covered by Code Section 7874, that, in eitheruse of case (i) or (ii), if finalized and made effective,fertilizers for particular agricultural applications. Ethanol production in the opinionUnited States contributes significantly to corn demand, due in part to federal legislation mandating use of our legal counselrenewable fuels. An increase in ethanol production has led to an increase in the amount of corn grown in the United States and to increased fertilizer usage on both corn and other crops that have also benefited from improved farm economics. While the current Renewable Fuel Standard (RFS) encourages continued high levels of corn-based ethanol production, a continuing “food versus fuel” debate and other factors have resulted in calls to eliminate or OCI’s legal counsel, (A) would reasonably be expectedreduce the renewable fuel mandate, or to cause New CF to be treatedeliminate or reduce corn-based ethanol as a U.S. domestic corporation for U.S. federal tax purposes or (B) would cause New CF to fail to qualify for relevant benefitspart of the U.S.-Netherlands Tax Treaty.renewable fuel mandate. This could have an adverse effect on corn-based ethanol production, planted corn acreage and fertilizer demand.

Developments in crop technology, such as nitrogen fixation, the conversion of atmospheric nitrogen into compounds that plants can assimilate, or nitrogen-efficient varieties, could also reduce the use of chemical fertilizers and adversely affect the demand for our products. Widespread adoption of emerging application technologies could disrupt traditional application practices, affecting the volume or types of products used and timing of applications. In addition, our obligationfrom time to consummate the combination is subject to a condition that we shalltime various state legislatures have received from our legal counsel (i) an opinion dated as of the closing date to the effect that Section 7874 of the Code (or any other U.S. tax laws), existing regulations promulgated thereunder, and official interpretation thereof as set forth in published guidance, should not apply in such a manner so as to cause New CF to be treated as a domestic corporation for U.S. federal income tax purposes from and after the closing date and (ii) an opinion dated as of the closing date to the effect that New CF should qualify for relevant benefits of the U.S.-Netherlands Tax Treaty. OCI’s obligations to consummate the combination are subject to a condition that OCI shall have received from OCI’s legal counsel an opinion dated as of the closing date to the effect that, for U.S. federal income tax purposes, the separation should be treated as a reorganization within the meaning of Section 368(a)(1)(D) and a distribution qualifying under Section 355 of the Code. In the event that one or more of the above conditions are not satisfied, the relevant party (or if applicable, each party) will determine, basedconsidered limitations on the factsuse and circumstances existing atapplication of chemical fertilizers due to concerns about the applicable time, whether to invokeimpact of these products on the applicable conditionenvironment. Any reduction in the demand for chemical fertilizer products, including any limitation on the use and not consummateapplication of chemical fertilizer, could affect the combination or waive the condition and consummate the combination (assuming the other closing conditions are satisfied or waived). Accordingly, any changes in applicable tax laws, regulations or the underlying facts before the closing datedemand for our products, which could jeopardize or delay the combination and/or have a material adverse effect on New CF’sour business, financial condition, results of operations and cash flows, and/or share price.

Our business is dependent on natural gas, the prices of which are subject to volatility.

Natural gas is the principal raw material used to produce nitrogen fertilizers. We use natural gas both as a chemical feedstock and as a fuel to produce ammonia, granular urea, UAN, ANurea ammonium nitrate solution (UAN), ammonium nitrate (AN) and other nitrogen products.

Because most of our nitrogen fertilizer manufacturing facilities are located in the United States and Canada, North American natural gas comprises a significant portion of the total production cost of our products. The price of natural gas in North America has been volatile in recent years. During 2015,2016, the daily closing price at the Henry Hub, the most heavily-traded natural gas pricing point in North America, reached a low of $1.54$1.49 per MMBtu on fourthree consecutive days in December 2015March 2016 and a high of $3.30$3.77 per MMBtu on January 16, 2015.December 8, 2016. During the three yearthree-year period ended December 31, 2015,2016, the daily closing price at the Henry Hub reached a low of $1.54$1.49 per MMBtu on fourthree consecutive days in December 2015March 2016 and a high of $7.94 per MMBtu on March 5, 2014.

We also have manufacturing facilities located in the United Kingdom. These facilities are subject to fluctuations associated with the price of natural gas in Europe. The major natural gas trading point for the United Kingdom is the National Balancing Point (NBP).Point. During 2015,2016, the daily closing price at NBP reached a low of $4.60$2.80 per MMBtu on September 1, September 12 and September 14, 2016 and a high of $6.60 per MMBtu on December 23, 2015 and December 24, 2015 and a high of $8.50 per MMBtu on February 12, 2015.30, 2016. During the three yearthree-year period ended December 31, 2015,2016, the daily closing price at NBP reached a low of $4.60$2.80 per MMBtu on December 23, 2015September 1, September 12 and December 24, 2015September 14, 2016 and a high of $16.00$11.10 per MMBtu on March 22, 2013.January 8, 2014.

Changes in the supply of and demand for natural gas can lead to periods of volatile natural gas prices. If high prices were to occur during a period of low fertilizer selling prices, it could have a material adverse effect on our business, financial condition, results of operations and cash flows.

The price of natural gas in North America and worldwide has been volatile in recent years and has declined on average due in part to the development of significant natural gas reserves, including shale gas, and the rapid improvement in shale gas extraction techniques, such as hydraulic fracturing and horizontal drilling. Future production of natural gas from shale formations could be reduced by regulatory changes that restrict drilling or hydraulic fracturing or increase its cost or by reduction in oil exploration and development prompted by lower oil prices and resulting in production of less associated gas. Additionally, increased demand for natural gas, particularly in the Gulf Coast Region, due to increased industrial demand and increased natural gas exports could result in increased natural gas prices. If such reduced production or increased demand were to occur, or if other developments adversely impact the supply/demand balance for natural gas in the United States or elsewhere, natural gas prices could rise, which could have a material adverse effect on our business, financial condition, results of operations and cash flows.

Our operations and those of our joint venture are dependent upon raw materials provided by third parties, and any delay or interruption in the delivery of raw materials may adversely affect our business.

We and our joint venture use natural gas and other raw materials in the manufacture of fertilizers. We purchase the natural gas and other raw materials from third party suppliers. Our natural gas is transported by pipeline to our facilities and those of our joint venture by third party transportation providers or through the use of facilities owned by third parties. Delays or interruptions in the delivery of natural gas or other raw materials may be caused by, among other things, severe weather or natural disasters, unscheduled downtime, labor difficulties, insolvency of our suppliers or their inability to meet existing contractual arrangements, deliberate sabotage and terrorist incidents, or mechanical failures. Our joint venture, Point Lisas Nitrogen Limited, has experienced numerous natural gas curtailments as discussed in the risk factor below titled "We are exposed to risks associated with our joint venture." In addition, the transport of natural gas by pipeline is subject to additional risks, including delays or interruptions caused by capacity constraints, leaks or ruptures. Any delay or interruption in the delivery of natural gas or other raw materials, even for a limited period, could have a material adverse effect on our business, financial condition, results of operations and cash flows.

Our transportation and distribution activities rely on third party providers and are subject to environmental, safety and regulatory oversight. This exposes us to risks and uncertainties beyond our control that may adversely affect our operations and exposes us to additional liability.

We rely on railroad, truck, pipeline, river barge and ocean vessel companies to transport raw materials to our manufacturing facilities, to coordinate and deliver finished products to our distribution system and to ship finished products to our customers. We also lease rail cars in order to ship raw materials and finished products. These transportation operations, equipment and services are subject to various hazards, including adverse operating conditions on the inland waterway system, extreme weather conditions, system failures, work stoppages, delays, accidents such as spills and derailments and other accidents and operating hazards. Additionally, due to the aging infrastructure of certain bridges, roadways, rail lines, river locks, and equipment that our third party service providers utilize, we may experience delays in both the receipt of raw materials or the shipment of finished product while repairs, maintenance or replacement activities are conducted. Also, certain third party service providers, particularly railroads, have experienced periodic service slowdowns due to capacity constraints in their systems which impact the shipping times of our products.

These transportation operations, equipment and services are also subject to environmental, safety, and regulatory oversight. Due to concerns related to accidents, discharges or other releases of hazardous substances, terrorism or the potential use of fertilizers as explosives, governmental entities could implement new regulations affecting the transportation of raw materials or finished products.

If shipping of our products is delayed or we are unable to obtain raw materials as a result of these transportation companies'companies’ failure to operate properly, or if new and more stringent regulatory requirements are implemented affecting transportation operations or equipment, or if there are significant increases in the cost of these services or equipment, our revenues and cost of operations could be adversely affected. In addition, increases in our transportation costs, or changes in such costs relative to transportation costs incurred by our competitors, could have a material adverse effect on our business, financial condition, results of operations and cash flows.

In the United States and Canada, the railroad industry continues various efforts to limit the railroads'railroads’ potential liability stemming from the transportation of Toxic Inhalation Hazard materials, such as the anhydrous ammonia we transport to and from our manufacturing and distribution facilities. For example, various railroads have implemented tariffs that include

provisions that purport to shift liability to shippers to the extent that liabilities arise from third parties with insufficient resources. TheseIf successful, these initiatives could materially and adversely affect our operating expenses and potentially our ability to transport anhydrous ammonia and increase our liability for releases of our anhydrous ammonia while in the care, custody and control of the railroads, for which our insurance may be insufficient or unavailable. New regulations also could be implemented affecting the equipment used to ship our raw materials or finished products. Increases in transportation costs, or changes in such costs

Our operations and the production and handling of our products involve significant risks and hazards. We are not fully insured against all potential hazards and risks incident to our business. Therefore, our insurance coverage may not adequately cover our losses.

Our operations are subject to hazards inherent in the manufacture, transportation, storage and distribution of chemical products, including ammonia, which is highly toxic and corrosive. These hazards include: explosions; fires; severe weather and natural disasters; train derailments, collisions, vessel groundings and other transportation and maritime incidents; leaks and ruptures involving storage tanks, pipelines and rail cars; spills, discharges and releases of toxic or hazardous substances or gases; deliberate sabotage and terrorist incidents; mechanical failures; unscheduled plant downtime; labor difficulties and other risks. Some of these hazards can cause bodily injury and loss of life, severe damage to or destruction of property and equipment and environmental damage, and may result in suspension of operations and the imposition of civil or criminal penalties and liabilities.

We maintain property, business interruption, casualty and liability insurance policies, but we are not fully insured against all potential hazards and risks incident to our business. If we were to incur significant liability for which we were not fully insured, it could have a material adverse effect on our business, financial condition, results of operations and cash flows. We are subject to various self-retentions, deductibles and limits under these insurance policies. The policies also contain exclusions and conditions that could have a material adverse impact on our ability to receive indemnification thereunder. Our policies are generally renewed annually. As a result of market conditions, our premiums, self-retentions and deductibles for certain insurance policies can increase substantially and, in some instances, certain insurance may become unavailable or available only for reduced amounts of coverage. In addition, significantly increased costs could lead us to decide to reduce, or possibly eliminate, coverage. There can be no assurance that we will be able to buy and maintain insurance with adequate limits and reasonable pricing terms and conditions.

In April 2013, there was a fire and explosion at the West Fertilizer Co. fertilizer storage and distribution facility in West, Texas. According to published reports, 15 people were killed and approximately 200 people were injured in the incident, and the fire and explosion damaged or destroyed a number of homes and buildings around the facility. Various subsidiaries of CF Industries Holdings, Inc. (the CF Entities) have been named as defendants along with other companies in lawsuits filed in 2013, 2014 and 2015 in the District Court of McLennan County, Texas by the City of West, individual residents of the County and other parties seeking recovery for damages allegedly sustained as a result of the explosion. The cases have been consolidated for discovery and pretrial proceedings in the District Court of McLennan County under the caption “In re: West Explosion Cases.” The two-year statute of limitations expired on April 17, 2015. As of that date, over 400 plaintiffs had filed claims, including at least 9 entities, 325 individuals, and 80 insurance companies. Plaintiffs allege various theories of negligence, strict liability, and breach of warranty under Texas law. Although we do not own or operate the facility or directly sell our products to West Fertilizer Co., products that the CF Entities have manufactured and sold to others have been delivered to the facility and may have been stored at the West facility at the time of the incident. The Court granted in part and denied in part the CF Entities'Entities’ Motions for Summary Judgment in August 2015. Thirty-four cases including the three cases scheduled to begin trial on October 12, 2015 and some of the ten cases scheduled to begin trial on February 1, 2016, werehave been resolved pursuant to confidential settlements fully funded by insurance. The remaining cases are in various stages of discovery and pre-trial proceedings. TheseThe next group of cases will be setwas reset for trial in the upcoming months at the discretion of the Court.beginning on April 3, 2017. We believe we have strong legal and factual defenses and intend to continue defending the CF Entities vigorously in the pending lawsuits. The increased focus on the risks associated with fertilizers as a result of the incident could impact the regulatory environment and requirements applicable to fertilizer manufacturing and storage facilities.

Cyber security risks could result in disruptions in business operations and adverse operating results.

We rely on information technology and computer control systems in many aspects of our business, including internal and external communications, the management of our accounting, financial and supply chain functions and plant operations. Business and supply chain disruptions, plant and utility outages and information technology system and network disruptions due to cyber attacks could seriously harm our operations and materially adversely affect our operating results. Cyber security risks include attacks on information technology and infrastructure by hackers, damage or loss of information due to viruses, the unintended disclosure of confidential information, the misuse or loss of control over computer control systems, and breaches due to employee error. Our exposure to cyber security risks includes exposure through third parties on whose systems we place significant reliance for the conduct of our business. We have implementedroutinely review and implement security procedures and measures in order to protect our systems and information from being vulnerable to evolving cyber attacks. We believe these measures and procedures are appropriate. However, we may not have the resources or technical sophistication to anticipate, prevent, or recover from rapidly evolving

Adverse weather conditions may decrease demand for our fertilizer products, increase the cost of natural gas or materially disrupt our operations.

Weather conditions that delay or disrupt field work during the planting, and growing, seasonsharvesting or application periods may cause agricultural customers to use different forms of nitrogen fertilizer, which may adversely affect demand for the forms that we sell or may impede farmers from applying our fertilizers until the following growing season,application period, resulting in lower demand for our products.

Adverse weather conditions during or following harvest may delay or eliminate opportunities to apply fertilizer in the fall. Weather can also have an adverse effect on crop yields, which could lower the income of growers and impair their ability to purchase fertilizer from our customers. Our quarterly financial results can vary significantly from one year to the next due to weather-related shifts in planting schedules and purchasing patterns.

Weather conditions or, in certain cases, weather forecasts, also can affect the price of natural gas, the principal raw material used to make our nitrogen fertilizer products. Colder than normal winters and warmer than normal summers increase the demand for natural gas for power generation and for residential and industrial use, which can increase the cost and/or decrease the availability of natural gas. In addition, adverse weather events such as very low temperatures leading to well freeze-offs or hurricanes affecting the Gulf of Mexico coastal states can impact the supply of natural gas and cause prices to rise.

We may notOur ability to use our tax net operating losses and certain other tax assets to offset taxable income could be able to completenegatively impacted if there is a change in our capacity expansion projects on schedule as planned, on budget or at all due to a number of factors, many of which are beyond our control.ownership.

We are constructing new ammoniaestimate that we generated a federal tax net operating loss of approximately $2 billion in 2016, arising primarily from accelerated federal tax depreciation and urea/UAN plants atfederal bonus depreciation on our complexcapital projects. In addition, we generated significant state income tax loss carryforwards and credit carryforwards as a result of state tax depreciation and loss carryforwards, as well as foreign tax credit carryforwards. We project that we will generate additional federal tax loss carryforwards in Donaldsonville, Louisiana,2017 primarily arising from accelerated federal tax depreciation on our capital projects. Our ability to use our tax net operating losses, tax credits and new ammonia and urea plants at our complex in Port Neal, Iowa. A portion of these multi-billion dollar projects was completed in late 2015 and the remaining projects are scheduled for completion at various times in 2016.

In addition, we intend to file a claim to carry back federal and other unforeseen difficulties.

We are dependent onsubject to taxes in the availabilityUnited States, where most of our operations are located, and performancenumerous foreign jurisdictions where our subsidiaries are organized. Tax rates in various jurisdictions in which we operate may be subject to significant change. Our future effective tax rate could be affected by changes in our mix of earnings from countries with differing statutory tax rates and tax systems, changes in valuation of deferred tax assets and liabilities or changes in tax laws or their interpretation.

We are also subject to regular reviews, examinations and audits by the IRS and other taxing authorities with respect to taxes inside and outside of the engineering firms, construction firms, equipment suppliers, transportation providersUnited States. Although we believe our tax estimates are reasonable, if a taxing authority disagrees with the positions we have taken, we could face additional tax liability, including interest and other vendors necessarypenalties. There can be no assurance that payment of such additional amounts upon final adjudication of any disputes will not have a material impact on our results of operations and financial condition.

We have used the cash we generate outside the United States primarily to design and buildfund development of our business in non-U.S. jurisdictions. If the new units on a timely basis and on acceptable economic terms. If any of the third parties fails to perform as we expect,funds generated by our abilityU.S. business are not sufficient to meet our expansion goalsneed for cash in the United States, we may need to repatriate a portion of our future international earnings to the United States. Under current U.S. tax laws, those international earnings would be affected.

We also need to comply with other unanticipatednew, evolving or revised tax laws and regulations. The enactment of, or increases in, tariffs or value added taxes, or other changes in the application of existing taxes, in markets in which we are currently active, or may be active in the future, or on specific products that we sell or with which our products compete, could have an adverse consequences,effect on our results of operations and financial condition.

The rules dealing with U.S. federal income taxation are continually under review by Congress, the IRS and the U.S. Department of the Treasury. According to publicly released statements, a top legislative priority of the new Congress and administration may be to enact significant reform of the Internal Revenue Code, including, but not limited to, significant changes to the taxation of business entities and the deductibility of interest expense and capital investment. There is a substantial lack of clarity as to the likelihood, timing and details of any such astax reform and the diversionimpact of management's attention fromany potential tax reform on us, and we cannot, at this time, determine whether any such changes will adversely affect us or our existing plants and businesses and other opportunities.taxation.

We may not be successful in the expansion of our business.

If we finance acquisitions, partnerships, joint ventures, business combination transactions or other major investments by issuing equity or convertible or other debt securities or loans, our existing stockholders may be diluted or we could face constraints under the terms of, and as a result of the repayment and debt-service obligations under, the additional indebtedness. A business combination transaction between us and another company could result in our stockholders receiving cash or shares of another entity on terms that such stockholders may not consider desirable. Moreover, the regulatory approvals associated with a business combination may result in divestitures or other changes to our business, the effects of which are difficult to predict.

We are subject to numerous environmental, health and safety laws, regulations and permitting requirements, as well as potential environmental liabilities, which may require us to make substantial expenditures.

We are subject to numerous environmental, health and safety laws and regulations in the United States, Canada, the United Kingdom and the Republic of Trinidad and Tobago, including laws and regulations relating to the generation and handling of hazardous substances and wastes; the cleanup of hazardous substance releases; the discharge of regulated substances to air or water; and the demolition of existing plant sites upon permanent closure. In the United States, these laws include the Clean Air Act, the Clean Water Act, the RCRA,Resource Conservation and Recovery Act, the CERCLA,Comprehensive Environmental Response, Compensation and Liability Act, the TSCAToxic Substances Control Act and various other federal, state, provincial, local and local laws.international statutes.

As a fertilizer company working with chemicals and other hazardous substances, our business is inherently subject tofaces risks of spills, discharges or other releases of hazardousthose substances into the environment. Certain environmental laws, including CERCLA, impose joint and several liability, without regard to fault, for cleanup costs on persons who have disposed of or released hazardous substances into the environment. Given the nature of our business, we have incurred, are incurring currently, and are likely to incur periodically in the future, liabilities under CERCLA and other environmental cleanup laws at our current facilities or facilities previously owned by us or other acquired businesses, adjacent or nearby third-party facilities or offsite disposal locations. The costs associated with future cleanup activities that we may be required to conduct or finance may be

Violations of environmental, health and safety laws can result in substantial penalties, court orders to install pollution-control equipment, civil and criminal sanctions, permit revocations and facility shutdowns. Environmental, health and safety laws change rapidlyregularly and have tended to become more stringent over time. As a result, we have not always been and may not always be in compliance with all environmental, health and safety laws and regulations. We may be subject to more stringent

enforcement of existing or new environmental, health and safety laws in the future. Additionally, future environmental, health and safety laws and regulations or reinterpretation of current laws and regulations may require us to make substantial expenditures. We sell, among other products, DEF,diesel exhaust fluid, which is subject to EPA emissions standards that may become more stringent in the future. Our costs to comply with, or any liabilities under, these laws and regulations could have a material adverse effect on our business, financial condition, results of operations and cash flows.

From time to time, our production of anhydrous ammonia has resulted in accidental releases that have temporarily disrupted our manufacturing operations and resulted in liability for administrative penalties and claims for personal injury. To date, our costs to resolve these liabilities have not been material. However, we could incur significant costs if our liability coverage is not sufficient to pay for all or a large part of any judgments against us, or if our insurance carrier refuses coverage for these losses.

We hold numerous environmental and other governmental permits and approvals authorizing operations at each of our facilities. Expansion or modification of our operations is predicated upon securing necessary environmental or other permits or approvals. A decision by a government agency to deny or delay issuing a new or renewed regulatory material permit or approval, or to revoke or substantially modify an existing permit or approval, or a determination that we have violated a law or permit as a result of a governmental inspection of our facilities could have a material adverse effect on our ability to continue operations at our facilities and on our business, financial condition, results of operations and cash flows. On October 1,26, 2015, the EPA releasedpublished a final regulation lowering the national ambient air quality standard for ozone. ThisOzone attainment designations are expected by October 2017, and this action is expected to result in additional areas of the country being classified as being in nonattainment with the ozone standard and subject to more stringent permitting requirements, which in turn could make it much more difficult and expensive to obtain permits to construct new facilities or expand our existing operations.

Future regulatory restrictions on greenhouse gas emissions in the jurisdictions in which we operate could materially adversely affect our business, financial condition, results of operations and cash flows.

We are subject to GHGgreenhouse gas regulations in the United Kingdom, Canada and the United States. In the United States, our existing facilities currently are only subject to GHG emissions reporting obligations, although our new and modified facilities are likely to be subject to GHG emissions standards included in their air permits. Our facilities in the United Kingdom are subject to regulatory emissions trading systems, which generally require us to hold or obtain emissions allowances to offset GHG emissions from those aspects of our operations that are subject to regulation under this program. Our facility in Alberta, Canada is subject to a provincial regulation requiring reductions in the facility'sfacility’s net emissions intensity, which can be met by facility improvements, the purchase of emissions offsets or performance credits, or contributions to a non-profit climate change fund established by Alberta. In June 2016, Alberta has recently announced that it is replacing its current approach with respect topromulgated the Climate Leadership Implementation Act, which will impose a wide-ranging carbon by introducing a carbon tax that applies across all sectors.tax. The carbon tax will be set at $20 per ton (Canadian dollars) effective January 1, 2017, rise to $30 per ton (Canadian dollars) effective January 1, 2018 and increase with the rate of inflation thereafter. In April 2015,Facilities such as ours that are subject to the province ofexisting specified gas emitters regulation will continue to be subject to this regulation in the near term, after which new product and sector-based performance standards (to be developed) will become effective. Our Courtright, Ontario Canada, announced that it intendsfacility will be subject to implement aOntario’s GHG cap and trade program.program beginning in January 2017, which regulation was finalized in May 2016. In November 2015, Ontario publishedaddition, in October 2016, Canadian Prime Minister Justin Trudeau announced that his government will introduce a notice seeking commentsplan to put a nationwide price on carbon emissions, which plan would serve as a floor for the design of its cap and trade system, which notice indicated that Ontario intended to commence operationGHG emissions reduction requirements of the capseparate Canadian provinces and trade program effective January 1, 2017. territories. The announced plan would impose a $10 per ton (Canadian dollars) charge beginning in 2018, rising to $50 per ton by 2022.

There are substantial uncertainties as to the nature, stringency and timing of any future GHG regulations. On December 12, 2015, 195 countries adopted by consensus a new international agreement known as the Paris Agreement. The Paris Agreement is intended to provide a framework pursuant to which the parties to the agreement will attempt to hold the increase in global average temperatures to below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels. The Paris Agreement, which has been accepted by the United States and ratified by Canada and the United Kingdom, went into effect in November 2016. However, as a result of the recent presidential election, the United States may decide to withdraw from the Paris Agreement (or the United Nations Framework Convention on Climate Change, which would also result in withdrawal from the Paris Agreement) or, prior to taking such actions, could disregard its commitments under the Paris Agreement. The impact of such actions, if they take place, on the future implementation of the Paris Agreement is uncertain. If the Paris Agreement remains in effect, it could result in more aggressive efforts to reduce GHG emissions in the jurisdictions in which we operate. More stringent GHG limitations, if they are enacted, are likely to have a significant impact on us, because our production facilities emit GHGs such as carbon dioxide and nitrous oxide and because natural gas, a fossil fuel, is a primary raw material used in our nitrogen production process. Regulation of GHGs may require us to make changes in our operating activities that would increase our operating costs, reduce our efficiency, limit our output,

require us to make capital improvements to our facilities, increase our costs for or limit the availability of energy, raw materials or transportation, or otherwise materially adversely affect our business, financial condition, results of operations and cash flows. In addition, to the extent that GHG restrictions are not imposed in countries where our competitors operate or are less stringent than regulations that may be imposed in the United States, Canada or the United Kingdom, our competitors may have cost or other competitive advantages over us.

Our operating results fluctuate due to seasonality. Our inability to predict future seasonal fertilizer demand accurately could result in our having excess inventory, potentially at costs in excess of market value, or product shortages.

The fertilizer business is seasonal. The degree of seasonality of our business can change significantly from year to year due to conditions in the agricultural industry and other factors. The strongest demand for our products in North America occurs during the spring planting season, with a second period of strong demand following the fall harvest. We and our customers generally build inventories during the low demand periods of the year to ensure timely product availability during the peak sales seasons. Seasonality is greatest for ammonia due to the short application season and the limited ability of our customers and their customers to store significant quantities of this product. The seasonality of fertilizer demand generally results in our sales volumes and net sales being the highest during the spring and our working capital requirements being the highest just prior to the start of the spring planting season.

If seasonal demand is less than we expect, we may be left with excess inventory that will have to be stored (in which case our results of operations will be negatively affected by any related increased storage costs) or liquidated (in which case the selling price may be below our production, procurement and storage costs). The risks associated with excess inventory and product shortages are exacerbated by the volatility of natural gas and nitrogen fertilizer prices and the relatively brief periods during which farmers can apply nitrogen fertilizers. If prices for our products rapidly decrease, we may be subject to inventory write-downs, adversely affecting our operating results. If seasonal demand is greater than we expect, we may experience product shortages, and customers of ours may turn to our competitors for products that they would otherwise have purchased from us.

A change in the volume of products that our customers purchase on a forward basis, or the percentage of our sales volume that is sold to our customers on a forward basis, could increase our exposure to fluctuations in our profit margins and materially adversely affect our business, financial condition, results of operations and cash flows.

We offer our customers the opportunity to purchase products from us on a forward basis at prices and delivery dates we propose. Under our forward sales programs, customers generally make an initial cash down payment at the time of order and pay the remaining portion of the contract sales value in advance of the shipment date. Forward sales improve our liquidity due to the cash payments received from customers in advance of shipment of the product and allow us to improve our production scheduling and planning and the utilization of our manufacturing and distribution assets.

Any cash payments received in advance from customers in connection with forward sales are reflected on our consolidated balance sheets as a current liability until the related orders are shipped, which can take up to several months.

We believe the ability to purchase products on a forward basis is most appealing to our customers during periods of generally increasing prices for nitrogen fertilizers. Our customers may be less willing or even unwilling to purchase products on a forward basis during periods of generally decreasing or stable prices or during periods of relatively high fertilizer prices due to the expectation of lower prices in the future or limited capital resources. In periods of rising fertilizer prices, selling our nitrogen fertilizers on a forward basis may result in lower profit margins than if we had not sold fertilizer on a forward basis. Conversely, in periods of declining fertilizer prices, selling our nitrogen fertilizers on a forward basis may result in higher profit margins than if we had not sold fertilizer on a forward basis. In addition, fixing the selling prices of our products, often months in advance of their ultimate delivery to customers, typically causes our reported selling prices and margins to differ from spot market prices and margins available at the time of shipment.

Our business is subject to risks involving derivatives, including the risk that our hedging activities might not prevent losses.

We often utilize natural gas derivatives to hedge our financial exposure to the price volatility of natural gas, the principal raw material used in the production of nitrogen-based fertilizers. We have used fixed-price, physical purchase and sales contracts, futures, financial swaps and option contracts traded in the over-the-counter markets or on exchanges. In order to manage our exposure to changes in foreign currency exchange rates, from time to time, we may use foreign currency derivatives, primarily forward exchange contracts.

Our use of derivatives can result in volatility in reported earnings due to the unrealized mark-to-market adjustments that occur from changes in the value of the derivatives that do not qualify for, or to which we do not apply, hedge accounting. To the

extent that our derivative positions lose value, we may be required to post collateral with our counterparties, adversely affecting our liquidity.

Hedging arrangements are imperfect and unhedged risks will always exist. In addition, our hedging activities may themselves give rise to various risks that could adversely affect us. For example, we are exposed to counterparty credit risk when our derivatives are in a net asset position. Additionally, the International Swaps and Derivative Association master netting arrangements for most of our derivative instruments contain credit-risk-related contingent features, such as cross default provisions and credit support requirements. In the event of certain defaults or a credit ratings downgrade, our counterparty may request early termination and net settlement of certain derivative trades or may require us to collateralize derivatives in a net liability position.

The counterparties to our derivatives are multi-national commercial banks,

We are reliant on a limited number of key facilities.

Our nitrogen fertilizer operations are concentrated in nine separate nitrogen complexes, the largest of which is the Donaldsonville complex, which currently represents approximately 35% of our ammonia production capacity and will representrepresented approximately 40% of our ammonia production capacity afteras of December 31, 2016, including the Donaldsonville and Port Neal capacity expansion projects, are fully operational.which were completed in 2016. The suspension of operations at any of these complexes could adversely affect our ability to produce our products and fulfill our commitments, and could have a material adverse effect on our business, financial condition, results of operations and cash flows. In addition, our Donaldsonville complex is located in an area of the United States that experiences a relatively high level of hurricane or high wind activity and our other complexes are located in areas that experience severe weather. Such storms, depending on their severity and location, have the potential not only to damage our facilities and disrupt our operations, but also to adversely affect the shipping and distribution of our products and the supply and price of natural gas in the respective regions. Moreover, our facilities may be subject to failure of equipment that may be difficult to replace and could result in operational disruptions.

We are subject to risk associated with our strategic venture with CHS Inc.

We are exposed to risks associated with our joint venture.

As of December 31, 2015, our remaining joint venture isWe have a 50% ownership interest in PLNL, (whichwhich owns aand operates an ammonia production facility in the Republic of Trinidad and Tobago).Tobago. Our joint venture partner shares a measure of control over the operations of our PLNL joint venture. As a result, our investment in our PLNL joint venture involves risks that are different from the risks involved in owning facilities and operations independently. These risks include the possibility that our PLNL joint venture or our partner: have economic or business interests or goals that are or become inconsistent with our economic or business interests or goals; are in a position to take action contrary to (or have veto rights over) our instructions, requests, policies or objectives; subject our PLNL joint venture to liabilities exceeding those contemplated; take actions that reduce our return on investment; or take actions that harm our reputation or restrict our ability to run our business.

In addition, we may become involved in disputes with our PLNL joint venture partner, which could lead to impasses or situations that could harm the joint venture, which could reduce our revenues or increase our costs.

Our PLNL joint venture operates anPLNL's ammonia plant that relies on natural gas supplied by Thethe National Gas Company of Trinidad and Tobago Limited (NGC)pursuant to a gas sales contract (the NGC Contract). The joint venture has experienced curtailments in the supply of natural gas curtailments duefrom NGC, which have reduced the ammonia production at PLNL. In 2016, NGC communicated to major maintenance activities being conducted at upstreamPLNL that it does not recognize the joint venture’s exercise of its option to renew the NGC Contract for an additional five-year term beyond its current termination date in September 2018, and that any NGC commitment to supply gas beyond 2018 will need to be based on new agreements regarding volume and price. PLNL has initiated arbitration proceedings against NGC and asserted claims in connection with NGC’s failure to supply the contracted quantities of natural gas, facilities and decreased gas explorationits refusal to recognize the joint venture’s exercise of its option to extend the NGC Contract. PLNL is seeking declaratory and development activity in Trinidad. These curtailments have continued into 2015injunctive relief, as well as damages for

past and we are unableongoing curtailments. Although the joint venture believes its claims against NGC to be meritorious, it is not possible to predict when the curtailmentsoutcome of the arbitration. There are significant assumptions in the future operations of the joint venture that are uncertain at this time, including the quantities of gas NGC will ceasemake available, the cost of such gas, the estimates that are used to occur. Indetermine the fourth quarteruseful lives of 2015, we recorded a $61.9 millionfixed assets and the assumptions in the discounted cash flow models utilized for recoverability and impairment testing.

As part of our impairment assessment of our equity method investment in PLNL, as we determined the carrying value exceeded the fair value and recognized a $134 million impairment charge in 2016. Previously, in 2015, we recognized an impairment charge of $62 million related to our equity method investment in PLNL. The carrying value of our equity method investment in PLNL exceeded its fair value, primarily due to the ongoing natural gas curtailments and the expectation that these curtailments will continue into the future. In addition, failureat December 31, 2016 is approximately $139 million. Failure to secure a long-term gas supply from NGC on a cost effective basis could adversely affect our ability to produce ammonia at the joint venture whichand could result in further impairment to the value of the joint venture, such as ceasing operations and writing off the remaining investment in PLNL, which could have a material adverse effect on our results of operations.

Acts of terrorism and regulations to combat terrorism could negatively affect our business.

Like other companies with major industrial facilities, we may be targets of terrorist activities. Many of our plants and facilities store significant quantities of ammonia and other materials that can be dangerous if mishandled. Any damage to infrastructure facilities, such as electric generation, transmission and distribution facilities, or injury to employees, who could be direct targets or indirect casualties of an act of terrorism, may affect our operations. Any disruption of our ability to produce or distribute our products could result in a significant decrease in revenues and significant additional costs to replace, repair or insure our assets, which could have a material adverse effect on our business, financial condition, results of operations and cash flows.

We are subject to risks associated with international operations.

Our international business operations are subject to numerous risks and uncertainties, including difficulties and costs associated with complying with a wide variety of complex laws, treaties and regulations; unexpected changes in regulatory environments; currency fluctuations; tax rates that may exceed those in the United States; earnings that may be subject to withholding requirements; and the imposition of tariffs, exchange controls or other restrictions.

Our principal reporting currency is the U.S. dollar and our business operations and investments outside the United States increase our risk related to fluctuations in foreign currency exchange rates. The main currencies to which we are exposed, besides the U.S. dollar, are the Canadian dollar, the British pound and the Euro.euro. These exposures may change over time as business practices evolve and economic conditions change, including, for example, in response to sudden global economic conditions resulting from measures like the referendum in the United Kingdom in June 2016, which resulted in a vote in favor of exiting the European Union (Brexit). We may selectively reduce some foreign currency exchange rate risk by, among other things, requiring contracted purchases of our products to be settled in, or indexed to, the U.S. dollar or a currency freely convertible into U.S. dollars, or hedging through foreign currency derivatives. These efforts, however, may not be effective and could have a material adverse effect on our business, financial condition, results of operations and cash flows.

We are subject to anti-corruption laws and regulations and economic sanctions programs in various jurisdictions, including the U.S. Foreign Corrupt Practices Act of 1977, the United Kingdom Bribery Act of 2010, and economic sanctions programs administered by the United Nations, the European Union and the Office of Foreign Assets Control of the U.S. Department of the Treasury, and regulations set forth under the Comprehensive Iran Accountability Divestment Act. As a result of doing business internationally, we are exposed to a risk of violating anti-corruption laws and sanctions regulations applicable in those countries where we, our partners or agents operate. Violations of anti-corruption and sanctions laws and regulations are punishable by civil penalties, including fines, denial of export privileges, injunctions, asset seizures, debarment from

government contracts (and termination of existing contracts) and revocations or restrictions of licenses, as well as criminal fines and imprisonment. The violation of applicable laws by our employees, consultants, agents or partners could subject us to penalties and could have a material adverse effect on our business, financial condition, results of operations and cash flows.

We are subject to antitrust and competition laws in various countries throughout the world. We cannot predict how these laws or their interpretation, administration and enforcement will change over time. Changes in antitrust laws globally, or in their interpretation, administration or enforcement, may limit our existing or future operations and growth.

Deterioration of global market and economic conditions could have a material adverse effect on our business, financial condition, results of operations and cash flows.

A slowdown of, or persistent weakness in, economic activity caused by a deterioration of global market and economic conditions could adversely affect our business in the following ways, among others: conditions in the credit markets could affect the ability of our customers and their customers to obtain sufficient credit to support their operations; the failure of our customers to fulfill their purchase obligations could result in increases in bad debts and impact our working capital; and the failure of certain key suppliers could increase our exposure to disruptions in supply or to financial losses. We also may experience declining demand and falling prices for some of our products due to our customers'customers’ reluctance to replenish inventories. Changes in global economic conditions can arise suddenly and the full impact of such changes can be difficult to ascertain, resulting in anxiety among market participants that can persist for protracted periods. For example, concern and uncertainty over the potential impact of Brexit on the global economy has resulted in increased volatility in global financial markets. The overall impact of achanges in global economic downturnconditions on us is difficult to predict, and our business could be materially adversely impacted.

In addition, conditions in the international market for nitrogen fertilizers significantly influence our operating results. The international market for fertilizers is influenced by such factors as currency exchange rates, including the relative value of the U.S. dollar and its impact upon the cost of importing of nitrogen fertilizers into the United States, foreign agricultural policies, the existence of, or changes in, import or foreign currency exchange barriers in certain foreign markets and the laws and policies of the markets in which we operate that affect foreign trade and investment.

FORWARD LOOKING STATEMENTS

From time to time, in this Annual Report on Form 10-K as well as in other written reports and verbaloral statements, we make forward-looking statements that are not statements of historical fact and may involve a number of risks and uncertainties. These statements relate to analyses and other information that are based on forecasts of future results and estimates of amounts not yet determinable. These statements may also relate to our prospects, future prospects, developments and business strategies. We have used the words "anticipate," "believe," "could," "estimate," "expect," "intend," "may," "plan," "predict," "project," "will" or "would" and similar terms and phrases, including references to assumptions, to identify forward-looking statements in this document. These forward-looking statements are made based on currently available competitive, financial and economic data, our current expectations, estimates, forecasts and projections about the industries and markets in which we operate and management's beliefs and assumptions concerning future events affecting us. These statements are not guarantees of future performance and are subject to risks, uncertainties and factors relating to our operations and business environment, all of which are difficult to predict and many of which are beyond our control. Therefore, our actual results may differ materially from what is expressed in or implied by any forward-looking statements. We want to caution you not to place undue reliance on any forward-looking statements. We do not undertake any responsibility to release publicly any revisions to these forward-looking statements to take into account events or circumstances that occur after the date of this document. Additionally, we do not undertake any responsibility to provide updates regarding the occurrence of any unanticipated events which may cause actual results to differ from those expressed or implied by the forward-looking statements contained in this document.

Important factors that could cause actual results to differ materially from our expectations are disclosed under "Risk Factors" and elsewhere in this Annual Report on Form 10-K. Such factors include, among others:

The following selected historical financial data as of December 31, 20152016 and 20142015 and for the years ended December 31, 2016, 2015 2014 and 20132014 have been derived from our audited consolidated financial statements and related notes included elsewhere in this document. The following selected historical financial data as of December 31, 2014, 2013 2012 and 20112012 and for the years ended December 31, 20122013 and 20112012 have been derived from our consolidated financial statements, which are not included in this document.