South Korean chemical manufacturer, Foosung Co has been asked by SK Hynix and Samsung Electronics to increase its supply of hydrogen fluoride. This move comes after Japan threatened to impose stronger curbs on the export of the chemical to South Korea, where it is used in the manufacturing of semiconductor chips by Huawei Technologies Co. and Apple Inc, apart from the two abovementioned firms.

“They are checking almost every day to secure more supplies from us.”, a spokesperson for Foosung told reporters. The person also added that Samsung and SK Hynix had also proposed to perform a quality check on the chemical being supplied by Foosung. However, considering the sensitive nature of the issue, the person did not wish to be named.

Similarly, both SK Hynix and Samsung refused to acknowledge if any such request was made. Most South Korean electronics manufacturers depend on Japanese chemical firms for hydrogen fluoride, but some source it from within the country and China as well.

Yonhap Infomax, a South Korean media firm, had reported on Tuesday that local suppliers had been asked by the two tech firms to increase their hydrogen fluoride supply to cut dependence on Japanese companies. An SK Hynix spokesperson told reporters that the company was testing the chemical supplied by numerous South Korean firms, but was mum on the details. The person further added that Don Kim, the company’s president, had flown to Japan on Tuesday to discuss the export scenario with local suppliers.

Though stockpiling of hydrogen fluoride is an option, companies generally refrain from it, considering its highly toxic nature.