The massive tank failure this week at the Nippon Dynawave Packaging mill in Longview released hundreds of thousands of gallons of “white liquor,” a highly corrosive chemical that’s now contaminated nearby drainage ditches and sent polluted wastewater into the Columbia River.

The process of paper making involves several chemicals that can cause serious injuries if a person is exposed to them.

Firefighters on Saturday were trying to cool a chemical tank “literally on the edge” of exploding in Garden Grove, California, as they worked to avert a disastrous “worst-case” scenario, the incident’s commander said.

Firefighters continue to cool a chemical storage tank with water to prevent it from breaching or exploding. Some 40,000 residents near the Orange County plant have been evacuated to shelters.

An "unprecedented" situation was taking hold in Orange County on Friday, as a chemical tank was at risk of spewing a highly toxic chemical that can cause severe respiratory distress and hospitalization,

Crews have recovered the remains of six of nine workers who were missing after a chemical tank ruptured at at paper mill in Washington state, officials said Thursday

Evacuation orders were issued to 40,000 Orange County residents. A fire official said a major spill or an explosion were the only expected outcomes.