The United States changed the scope of its 50-per-cent tariff list on Canadian goods today. U.S. Customs and Border Protection says 122 additional tariff classifications are now covered, while 10 were removed—including salt, cement and certain paper goods. The changes offer a useful lesson in what happens when tariffs start colliding with the supply chains they were supposed to pressure.
There are two ways to read the latest turn in the Canada-U.S. trade fight. Washington has added more Canadian products to a punishing 50-per-cent tariff, but it has also taken other products off the list. The additions are the obvious story. The exemptions may be the more revealing one.
The United States is making some Canadian goods substantially more expensive to import while deciding that a different mix of products under the tariff would, in the White House's words, "better serve the public interest." That tells us something about retaliation, but it also tells us something about how deeply the two economies remain connected.
What actually changed today
The Section 338 tariffs themselves are not new. They became effective at 12:01 a.m. Eastern on August 22 after a three-day suspension expired without an agreement between Ottawa and Washington. What changed at 12:01 a.m. Eastern on September 15 was the scope of the products covered.
U.S. Customs and Border Protection says 122 additional Harmonized Tariff Schedule classifications are now subject to the Section 338 duties, while 10 classifications were removed. The revised measures apply to covered goods even if they otherwise qualify under the Canada-U.S.-Mexico trade agreement, and some newly covered products can also face separate U.S. Section 232 tariffs.
Among the newly covered goods are additional cheeses and other dairy products, writing and graphic paper, steel structures and beams, aluminum profiles and tubing, welding materials, golf carts and similar vehicles, motorboats, furniture, mattresses and lamps. The official tariff annex runs through the precise classifications.
That precision matters. Canadian exporters should not make shipping decisions based on newspaper shorthand—or this article alone—because the legal treatment depends on the Harmonized Tariff Schedule code. But the direction is clear: Washington has broadened the pressure on several Canadian manufacturing and resource sectors.
This is also a different side of the trade fight from the Canadian counter-tariffs that reached the shopping cart on September 8. Those measures affect U.S. goods entering Canada. Today's changes affect Canadian goods entering the United States.
Then there is the other list
The products Washington removed are just as revealing.
As of today, the additional 50-per-cent Section 338 tariff no longer applies to 10 classifications covering certain whiskies and liqueurs sold in containers larger than four litres, salt and pure sodium chloride, Portland cement other than white cement, chemically pure sugars, specified tissue and sanitary paper, certain household and hospital paper articles, refined lead, low-voltage switchgear assemblies, and fishing-rod parts and accessories. CBP lists the affected classifications in its implementation guidance.
A terminology warning is useful here. Some coverage has described the paper exemption simply as "toilet paper." The actual tariff language is more technical and covers certain toilet or facial tissue, towel or napkin stock and sanitary paper in rolls or sheets, along with specified household and hospital paper articles. The annex itself cautions that its product descriptions are informational and that the underlying HTSUS provisions determine the legal scope.
Trade policy can make even toilet paper complicated.
The White House summary specifically highlighted rock salt and cement among the products being removed while goods such as all-terrain vehicles and additional dairy products were being added. That makes salt and cement useful places to look at why the tariff list changed.
Salt is not exactly a luxury import
The United States produces plenty of salt domestically, but it also imports a significant amount. According to the U.S. Geological Survey, U.S. net import reliance for salt reached about 31 per cent of apparent consumption in 2025, with Canada supplying roughly 21 per cent of U.S. salt imports over the 2021–2024 period.
Much of that salt is not destined for the kitchen table. About 37 per cent of U.S. salt consumption goes to highway de-icing, while another large share is used by the chemical industry. USGS also reported a regional rock-salt shortage in New York in early 2025 and estimated that rock-salt imports increased as state and local transportation departments used more salt than they had in 2024.
Put a 50-per-cent tariff into that supply chain and the cost does not stay neatly on the Canadian side of the border. A Canadian producer may absorb some through lower margins, but U.S. importers, state and municipal governments, businesses and ultimately taxpayers can absorb some too.
Removing Canadian salt from the tariff list does not mean the United States cannot buy salt somewhere else. It does show why broad tariffs become harder to sustain when they run into established supply chains and basic commodities Americans themselves use in large quantities.
Cement tells a similar story
The pattern is much the same with cement. The United States has a large domestic industry, but USGS estimates U.S. net import reliance for cement at about 21 per cent of apparent consumption in 2025. Canada is an important part of that supply, providing about 20 per cent of U.S. cement imports over the 2021–2024 period.
Cement is not a discretionary luxury purchase. It becomes roads, bridges, factories, homes, warehouses, data centres and much of the infrastructure governments are trying to build more of. A 50-per-cent tariff can hurt a Canadian cement producer while also raising input costs for an American construction project.
That is one of the recurring complications of treating an integrated North American economy as though costs imposed at the border will stay politely on one side of it.
The additions still matter
None of this should be mistaken for a retreat from the tariff fight. The revised lists extend the 50-per-cent tariff to 122 additional classifications, covering goods across dairy, paper, metals, furniture, boats and other manufactured products.
CUSMA does not provide a shield from these Section 338 duties simply because a covered product meets the trade agreement's rules of origin. The updated list also overlaps with some products already covered by U.S. Section 232 tariffs, and the Congressional Research Service says the measures can stack to produce additional tariffs of as much as 100 per cent on certain products.
For a Canadian manufacturer with a large U.S. customer base and thin margins, that can determine whether a sale remains economically viable at all.
The United States will remain Canada's most important trading partner for the foreseeable future. Geography, infrastructure and decades of integrated production make that both unavoidable and valuable. But the recurring lesson from this trade dispute is that Canada needs more customers, more routes to market and more room to manoeuvre when access to its largest market becomes a political weapon.
The exemptions are a map too
Canada depends far more heavily on access to the American market than the United States depends on Canada. Pretending otherwise would be economic fantasy. But that does not mean continental integration runs in only one direction.
American automakers use Canadian components. Builders use Canadian materials. State and municipal governments buy Canadian commodities. Manufacturers depend on Canadian inputs, and consumers buy Canadian finished goods. The relationship is deeply unequal in scale without being one-directional in value.
Today's exemptions offer a small map of where that distinction matters. Washington did not suddenly develop a sentimental attachment to Canadian cement or rock salt. It reconsidered parts of the tariff list and concluded that a different mix better served U.S. interests.
The Congressional Research Service notes that some products later removed had already attracted concern from U.S. lawmakers. One example it cites is Sen. Jerry Moran's warning about salt tariffs affecting Kansas businesses, local governments and taxpayers.
That is a more useful way to think about leverage than assuming every Canadian export automatically gives Canada bargaining power. Most do not. But some supply relationships matter enough to both sides that disrupting them creates costs—and therefore pressure—on both sides of the border. Canada should know exactly where those relationships are.
September 29 is the next date to watch
Today's tariff changes are not the end of this round. Washington has separately announced import bans on specified Canadian goods under its alcohol, dairy and motor-vehicle Section 338 actions, beginning at 12:01 a.m. Eastern on September 29. The Congressional Research Service outlines the coming exclusions and their relationship to the current tariffs.
That would be a materially different escalation. A tariff leaves access to the market in place at a higher price; an import ban removes market access for the covered goods altogether.
We'll deal with that scoreboard when September 29 arrives.
For now, Canada needs to know what the United States is willing to tariff. It should pay equally close attention to what the United States decides is too useful to make more expensive.