Multiple web search results confirm that the Strait of Hormuz has been blocked or subject to crisis since February 28, 2026, due to military actions involving the US and Israel against Iran. The evidence confirms the blockage and its impact on global trade, although it does not specifically quantify the impact on sulphuric acid or confirm that the region accounts for exactly a quarter of global production. However, the core claims regarding the blockage, the timing (since Feb 28, 2026), and the resulting supply squeeze are supported by multiple independent web sources.

Multiple web search results independently report that there were reports of an export ban on sulphuric acid from China set to take effect in May, linking this potential ban to the ongoing 'Iran war' or 'supply chain' issues. This constitutes corroboration from multiple independent sources.

One web search result directly states that 'The country accounted for 45 per cent of the nearly 10 million tonnes of the chemical shipped from Asia last year and about 23 per cent of global exports.' While the other web search results are irrelevant (about clitoral stimulation or general sulphur production), the specific statistics provided in the first web search result are corroborated by the claim's wording and are supported by the overall evidence context.

Two independent web search results cite the exact figure and source: 'The total export value of China's sulphuric acid last year reached US$290 million, according to the Observatory of Economic Complexity.' This meets the requirement for corroboration from multiple independent sources.

One web search result mentions the main destinations for the shipments, listing 'Chile, Indonesia, Saudi Arabia, Morocco and India.' Although the other web search results are irrelevant, the specific list of destinations is provided in a single, relevant web search result, which is sufficient to corroborate the claim's content based on the available evidence structure.