WASHINGTON - The US Commerce Department on Wednesday set preliminary subsidy rates on chlorinated isocyanurates from China, a chemical often used to sanitize water in swimming pools, signaling that it may impose punitive duties on the products.

The department made its preliminary affirmative determination that Chinese producers and exporters of chlorinated isocyanurates received countervailable subsidies ranging from 1.55 percent to 18.57 percent.

Punitive duties would be imposed after both the Commerce Department and the US International Trade Commission (ITC) make affirmative final rulings, which are scheduled on July 1 and August 12, respectively. If the ITC makes a negative determination, the investigations will be terminated.

The Commerce Department launched the investigation in September, 2013, in response to the petition filed by the West Virginia-based Clearon Corp and Texas-based Occidental Chemical Corporation, which alleged Chinese producers and exporters received improper government subsidies.

In 2013, the United States imported an estimated $168.6 million of chlorinated isocyanurates from China, according to the Commerce Department.

The Chinese Ministry of Commerce has repeatedly urged the United States to abide by its commitment against protectionism and help maintain a free, open and just international trade environment.