Raw materials, energy and freight are critical inputs to our business, and make up a substantial portion of our cost of sales. We strive to minimize the extent to which the volatility in the prices of these inputs affects our business. However, as described in greater detail below, these efforts are imperfect and we cannot guarantee that we will be able to mitigate the negative impacts on our business of that volatility. For example, during 2021 and 2022, we experienced substantial, broad-based volatility in the prices for these inputs to our business that were greater than we had experienced in the recent past, which meaningfully impacted our results of operations in those years.
The primary raw materials used in our products are plastic resins (principally polystyrene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyethylene and polylactic acid), fiber (principally raw wood, wood chips and recycled newsprint) and paperboard (principally cartonboard and cupstock). Changes in the prices of raw materials are generally due to movements in commodity market prices, although some raw materials, such as wood, may be affected by local market conditions (including weather) as well as the commodity market. These conditions can be affected by broader macroeconomic trends, such as the macroeconomic disruptions resulting from the Russian invasion of Ukraine in 2022 and the elevated levels of inflation experienced beginning in the second half of 2021. For more information on the impact of macroeconomic trends on our business, please refer to the risk factor under the caption "Our business is subject to risks related to global economic conditions, including inflation and interest rates, consumer demand, global supply chain challenges and other macroeconomic issues that could have an adverse effect on our business and financial performance."
We typically do not enter into long-term purchase contracts that provide for fixed prices for our principal raw materials. While we enter into hedging agreements from time to time for some of our raw materials and energy sources, such as resin (or components thereof) and natural gas, to minimize the impact of such fluctuations, these hedging agreements do not cover all of our needs, hedging may reduce the positive impact we may otherwise receive when raw material prices decline and hedging arrangements may not always be available at commercially reasonable rates or at all, as is the case with our supply of energy in California, for example.
In addition, over the last several years, there has been a trend toward consolidation among suppliers of many of our principal raw materials, and we expect that this trend may continue. Consolidation among our key suppliers could enhance their ability to increase prices, forcing us to pay more for such raw materials, purchased either directly from these existing suppliers or from costlier alternative suppliers. We may be unable to pass on such cost increases to customers which could result in lower margins or lost sales. Consolidation among our suppliers also increases our vulnerability to catastrophic events impacting particular geographic regions. For more information, please refer to the risk factor "Natural disasters, public health crises and other catastrophic events outside of our control could damage our facilities or the facilities of third parties on which we depend, which could have an adverse effect on our financial condition or results of operations."
Although many of our customer pricing agreements include raw material cost pass-through mechanisms, which mitigate the impact of changes in raw material costs, not all of them do. For those that do, the contractual price changes do not occur simultaneously with raw material price changes. Due to this contractual delay, as well as differences in timing between purchases of raw materials and sales to customers, there is often a lead-lag effect during which margins are negatively impacted in periods of rising raw material costs and positively impacted in periods of falling raw material costs. Moreover, many of our sales are not covered by such pass-through mechanisms. While we also use price increases, whenever possible, to mitigate the effect of raw material cost increases for customers that are not subject to raw material cost pass-through agreements, we may not be able to pass on cost increases to our customers on a timely basis, if at all, and consequently may not be able to recover the lost margin resulting from cost increases. Additionally, an increase in the selling prices for the products we produce resulting from a pass-through of increased raw material, energy or freight costs could adversely affect sales volumes.
In addition to our dependence on primary raw materials, we are also dependent on different sources of energy and other utilities for our operations, such as coal, fuel oil, electricity and natural gas. For example, our Beverage Merchandising segment is susceptible to price fluctuations in natural gas as it consumes significant amounts of natural gas to convert raw wood and wood chips to liquid packaging board. In addition, if some of our large energy contracts were to be terminated for any reason or not renewed upon expiration, or if market conditions were to substantially change resulting in a significant increase in the price of coal, fuel oil, electricity, natural gas or other utilities, we may not be able to find alternative, comparable suppliers or suppliers capable of providing such energy and utilities on terms satisfactory to us. For instance, climate-related extreme weather conditions, such as hurricanes, flooding, droughts and deep freezes, have the potential to substantially change market conditions and increase prices for our energy and utilities. As a result of any of these events, our business, financial condition and operating results may suffer.
We are also dependent on third parties for the transportation of both our raw materials and other products that we purchase for our operations and the products that we sell to our customers. In certain jurisdictions, we are exposed to import duties and freight costs, the latter of which is influenced by carrier availability and the fluctuating costs of oil and other transportation costs. In recent years, the supply-chain disruptions that began during the coronavirus pandemic substantially increased our freight costs and the lead time associated with shipping our products, although these impacts moderated during 2022. Although some of our customer agreements include pass-through mechanisms for increased freight costs similar to the mechanisms for increases in raw materials costs, not all of our contracts contain these provisions, and those that do are subject to the same "lead-lag" effect described above.
Our business has substantial exposure to freight costs and freight-related disruptions, in particular domestic freight. We seek to reduce our exposure to freight-related disruptions through efforts to, among other things, reduce the need for transfer freight by producing the right product in the right place, increase warehouse automation and efficiency and decrease interdependencies. However, we may not be successful, and if we are not, our business would be negatively affected.
Governmental actions, like tariffs and trade sanctions, also impact the cost of raw materials and other goods and services that our business uses. For example, U.S. tariffs on products imported from certain countries and trade sanctions against certain countries, including on Russia following its invasion of Ukraine, have impacted the cost of certain raw materials, including resin, and other goods and services required to operate our business. Major developments in trade relations, including the imposition of new or strengthened tariffs or sanctions by the United States and other countries, could have a material adverse effect on our business, financial condition and results of operations.