Mark Drajem and Jack Kaskey of Bloomberg have a long piece Friday looking at whether lax regulatory oversight may have played a role in the deadly explosion of the West Fertilizer Co. retail facility in Texas on Wednesday that killed at least 12 people.

A person looks on as emergency workers fight a house fire after a nearby fertilizer facility exploded in West, Tex. (Rod Aydelotte/AP)

There's nothing conclusive here, but there are a few notable tidbits in the piece:

-- "The Texas plant that was the scene of a deadly explosion this week was last inspected by the Occupational Safety and Health Administration in 1985."

-- "There are no federal rules mandating that such plants be located away from residential areas, and the current company safety plans aren’t always shared widely with residents nearby."

-- "[West Fertilizer Co.] has been cited for a series of violations over the past few years. The U.S. Pipeline and Hazardous Materials Safety Administration on June 12 ordered the company to pay $5,250 for improperly planning to transport anhydrous ammonia. ... The U.S. Environmental Protection Agency conducted an inspection of the risk management plan at the plant in 2006, and found a number of deficiencies, including that the company was two years late filing the document."

-- "Texas environmental regulators investigated the facility seven times between 2002 and 2007. An odor complaint in June 2006 triggered an inspection that resulted in a notice of violation for operating without a required air permit."

-- "[E]nvironmental groups, unions and safety groups have been pushing the U.S. to tighten federal oversight of chemical production and storage facilities."

-- "Lobbying groups for these plants say the risks are limited and they now face a panoply of regulations and oversight."

The headline fact here is that the Occupational Safety and Health Administration (OSHA) hadn't inspected the West facility since 1985. It's not yet clear, however, whether more inspections would have actually averted whatever problem led to the explosion — the Labor Department says that OSHA is currently sending inspectors to the blast site to see if there had been health or safety violations.

But that statistic does highlight the fact that OSHA increasingly lacks the manpower to perform as many on-site inspections as it used to. Here's a chart from the agency showing the drop in the number of compliance officers per worker since the 1970s:

Currently there are about 2,200 inspectors for 8 million workplaces. And OSHA typically only inspects workplaces after they receive a complaint. On top of all of that, the fines involved for violations are often quite small  — back in 1985, OSHA fined the West, Texas facility in question just $30 "for a serious violation for storage of anhydrous ammonia." (The maximum fine for a serious violation is $7,000.*)

Meanwhile, state health and safety regulators can't always fill in the gap. This week, the Government Accountability Office issued a report noting that 22 states surveyed have failed to meet minimum workplace-safety inspection goals, due to state budget cuts and reduced staffing.

There's a more complicated debate about how many inspectors, exactly, the country should have — about 4,600 Americans still die in workplace accidents every year, although that rate has been steadily declining for the past two decades. Still, the chart above goes some way toward explaining why a facility can go without an OSHA inspection for more than 20 years.

Related: Here's our primer from Thursday on the explosion and the U.S. fertilizer industry as a whole. Note one update: There appears to have been as much as 270 tons of ammonium nitrate at the West facility, which could explain the explosion. (Previous reports had only noted that the facility stored and distributed 54,000 pounds of anhydrous ammonia, which is flammable only at extremely high temperatures.)

Correction: The maximum OSHA penalty for a serious violation is $7,000, not $1,000 as originally stated.