The Chronicle received AkzoNobel Surface Chemistry's Tier Two in 2016, after the publication of the report. A&M evaluated its inventory using the study methodology, and the plant landed on the high potential for harm list.

Three companies moved down to the mid-tier after giving the Chronicle updated information on chemicals and A&M recalculated scores.

A&M researchers wanted to factor in each facility's accident history, but comprehensive accident histories don't exist. So researchers endorsed the use of regulatory histories by the Chronicle and recommended that facilities with OSHA process safety violations receive a one-point penalty. Six facilities moved from the mid-tier to the highest category due to inspection histories.

The A&M report included facilities outside our metro area, because some companies in Harrison County mistakenly provided their chemical inventories to Houston-area Local Emergency Planning Committees. The Chronicle removed those facilities from its list.

There are differences between the original Texas A&M report, published in January 2016, and the data used by the Chronicle in the Chemical Breakdown series.

In response to the DuPont accident in November 2014, the Houston Chronicle obtained the chemical inventories of more than 2,500 businesses in Greater Houston. Chemical safety experts at Texas A&M University’s Mary Kay O’Connor Process Safety Center then ranked the potential for harm from each facility should an incident occur.

The Texas A&M analysis

Degesch America’s pesticide warehouse is surrounded by a chain-link fence north of Pearland. The Pearl Theater is across the street. The only signs of potential danger at Degesch are two diamond placards near the front door, marked with colors and numbers that, to first-responders, offer important warnings: reacts with water, highly flammable, fatal if inhaled.

The aluminum phosphide inside is so toxic it can’t legally be used within 100 feet of a building that could be occupied by living creatures.

Degesch ranked second for potential harm in the A&M analysis, partly because of the pesticide’s toxicity and also because it can house up to 75,000 pounds. It took less than 2 pounds of aluminum phosphide pellets placed in the ground around a home in Utah to produce enough gas to slowly kill a 4-year-old and her baby sister in 2010.

“There’s 1,200 chemical pesticides out there, and I’d put this one at the top of the list of things that scare me,” said Dave Stone, an environmental toxicologist and former director of the National Pesticide Information Center at Oregon State University.

The A&M analysis does not measure the risk of an accident happening, where a problem is likely to occur or the safety of the operations at a given facility.

Mannan noted that the properties that make chemicals dangerous also make them inherently useful. He hopes the analysis will inspire industry and government to better manage the risks.

Facilities across the country would likely produce similar results, in terms of the percentages in each tier, if the same methodology was applied, Mannan said.

Federal law requires companies to file inventories that include any of more than 500,000 hazardous products. Based on the data collected from greater Houston companies, A&M evaluated 983 substances. But under the EPA’s Risk Management Program, its chief accident prevention strategy, the agency looks at only 148 chemicals, ignoring places like Degesch.

The A&M study does not cover all of greater Houston.

Many facilities that produce or house hazardous chemicals couldn’t be identified by the Chronicle because the state allowed local governments to withhold inventories, citing a Texas law that restricts information that might be useful to terrorists. Brazoria and Galveston counties, home to some of the largest concentrations of chemical plants in the world, refused the paper’s request. So did Fort Bend and Waller counties.

A federal right-to-know law mandates disclosure, under the theory that the public is better protected by being informed. The law is not enforced.

Degesch rejected interview requests from the Chronicle – two employees hung up on reporters – and an inquiry to the company’s German headquarters went unanswered.

Peter van Nifterik, president of the Pearl Theater, knew nothing about the pesticide stored at Degesch. He assumed the facility was as benign as the plumbing place next door.

If an incident happened at Degesch during a show, Van Nifterik said he wouldn’t know whether to take shelter or evacuate.

Pearland neighbors

Degesch is in a light industrial park, with warehouses, crane suppliers and machine shops, and is about three quarters of a mile from Shadow Creek Ranch.

The suburban community of up to 12,000 homes with sought-after schools is the kind of place where people live precisely because it’s nowhere near the Houston industrial complex.

But other sites of concern are on either side of the industrial park. AkzoNobel Surface Chemistry operates a 45-acre plant southwest of Degesch that, among dozens of other hazardous materials, stores up to 2 million pounds of ethylene oxide, a highly flammable, explosive and toxic gas.

The plant has tanks and a couple of towers, but it doesn’t look like its massive counterparts on Houston’s east side. People with extensive experience in Pearland real estate – two salespeople for home builders and one agent – said prospective buyers almost never ask about AkzoNobel, yet most of Shadow Creek Ranch is within two2 miles, the range used in the A&M analysis. Many in the neighborhood took notice of the plant as a suspect after an offensive odor materialized last year. State officials are investigating possible sources, including a nearby landfill.

The company is confident the plant isn’t the source of the odor, spokesman George Nolan said, and has invited nearby residents for site visits.

For ethylene oxide and other hazardous materials, AkzoNobel often does more than federal safety and environmental standards require, Nolan said.

East of Degesch, tucked among the trees on Hooper Road, Syntech Chemicals occupies little more than three3 acres, and stores up to 50,000 pounds of formaldehyde solution, considered highly corrosive, toxic and flammable. It also has about a dozen other hazardous chemicals.

In 2002, fire ignited several 10,000-gallon tanks of methyl alcohol. Explosions destroyed most of the plant and sent a plume of black smoke toward the Sam Houston Tollway, snarling rush-hour traffic. Investigators attributed the blaze to an overheated oil reactor. Three months later, one of the tanks caught fire again. OSHA fined the company more than $100,000 for violating chemical process safety standards.

Three years ago, OSHA inspectors – prompted by a complaint – found hoses attached with hanger wires or patched with duct tape because clamps were damaged or missing. Employees told investigators that a worker damaged his eyesight after being sprayed with chemicals when he disconnected a hose.

Syntech Vice President James Gordon, in an email, attributed the 2002 fire to a faulty valve. The company rebuilt the plant, upgrading to the most modern equipment and safety features, he said.

Syntech then ran it for 11 years, OSHA found, without properly inspecting certain pressure relief valves, the last line of defense against fires, explosions and toxic releases.

The company reported that it fixed the problems from the 2013 inspections within one year, OSHA data shows. Gordon called the company’s compliance record in the last 15 years exemplary. “We at Syntech do not take safety lightly or as an afterthought,” he said.

Syntech, Degesch and AkzoNobel were in place long before Shadow Creek Ranch’s developers broke ground in 2001. None of the facilities will be visible above the treeline from the neighborhood’s new sports complex, under construction less than a mile from Syntech and a couple thousand feet from the other plants.