As of Wednesday morning, more than 195,000 individuals have registered for assistance.
Arkema SA and public health officials warned of the risk of more explosions and fires at a chemical plant owned by the firm.
Fifty eight counties are under Texas disaster declaration.
The affected refineries imported about 1.6 million barrels of oil a day past year, including 410,000 from Mexico, 380,000 from Saudi Arabia and 340,000 from Venezuela, according to data from the Energy Information Administration.
The National Weather Service's 4 a.m. update reports Harvey make its second US landfall near Cameron, Louisiana, in the pre-dawn hours of Wednesday.The storm continued moving to the NNE (30 degrees) at 7 mph with maximum sustained winds of 45 mph.
Harvey is now threatening to dump an additional 3 to 6 inches of rain from southwestern Louisiana into western Kentucky, the National Hurricane Center said. Authorities said beds were floating in places and residents were sitting in wheelchairs surrounded by water.More news: Four Companies Awarded Contracts to Build Border Wall Prototypes
The company says it's "deeply sorry that we gave anyone even the momentary impression that we were trying to take advantage of the situation".
Houston Police sergeant on his way to work and a Beaumont mother who was swept by water were confirmed dead on Tuesday.
But last night, the safety of that civic center was breached, too, according to KHOU.
Parts of Louisiana and Texas are under flash flood warnings through Wednesday morning, affecting areas where hundreds of thousands of people live.
In Houston, where Mayor Sylvester Turner issued a nighttime curfew to aid search efforts and thwart potential looting, the two major airports have reopened on a limited basis, signaling a slow return to normality.
Some 779,000 Texans had been ordered to evacuate their homes and another 980,000 had fled voluntarily amid concerns that swollen reservoirs and rivers could bring new flooding, according to Department of Homeland Security acting Secretary Elaine Duke.More news: Hy-Vee helping those affected by Hurricane Harvey
Five days after Harvey first made landfall, the Federal Emergency Management Agency said it's still in "lifesaving, life-sustaining" mode, with recovering survivors being the top priority. Houston's numbers dominate on that note, along with the city's sheer number of homes - an estimated 30,000 to 40,000 - that have been destroyed by the storm.
And those homes "will be inundated for several weeks", said Jeff Lindner with Harris County Flood Control. "If you called, we are coming", Freeman wrote shortly after midnight, via Facebook. "Things are going to get better".
Volunteers have come the Houston region to lend a hand and their boats.
Many people who watched the video - and those who saw the city's other notices - responded by posting addresses and locations of people who are stranded and need help.More news: Victoria's Secret annual fashion show to be held in Shanghai in November