Estimating the number of hazardous materials accidents that affect the public is difficult. Many go unreported. There are at least five national databases of chemical spills, including one for worker accidents and one from the Department of Transportation, and they all have limitations.
For worker accidents, the database by the U.S. Department of Labor's Occupational Safety and Health Administration is considered the best available. Yet officials agree that a lack of consistent reporting among states leads to under-reported accounting. The numbers clearly are imprecise: While the HSEES database reported 56 chlorine accidents with injuries in roughly one-third of the states in just one year, the OSHA database reported only 45 chlorine accidents involving workers nationally over 10 years.
Representatives of the Chlorine Institute, the trade group most familiar with the chlorine industry, said it couldn't discuss the situations in which most chlorine accidents occur. They also wouldn't comment on the data showing the frequency of injuries and evacuations, saying they weren't familiar with the HSEES database or the studies.
"Incidents are rare" in the production of chlorine among Chlorine Institute members, said Frank Reiner, president of the national trade group of 220 manufacturers and distributors. In an e-mail, Reiner said, "the safety performance of the industry has been very good" and his group shares information among members to avoid future problems.
Chlorine is arguably the most essential chemical in use today, industry experts say. It is produced in such large volumes because it can be easily combined with other elements and molecules, transforming it into new classes of chemicals. Industry considers it vital to the synthesis of plastics, drugs, microchips and many other products around the globe. Though there are alternatives for some uses, there are few equally effective and viable substitutes for others, such as water disinfection.
About 93 percent of pharmaceuticals are manufactured with chlorine.
"Chlorine is not in the final product, but it is needed at an intermediate stage to direct reactivity and make sure you make the molecule you want. Being able to avoid the use of chlorine in these cases is a very intense area of current research in green chemistry," said Audrey Moores, an assistant professor in the Department of Chemistry at McGill University in Montreal.
In Tulare last year, the source of the poison released at the recycling plant was a one-ton pressurized cylinder, unmarked as hazardous and accepted in good faith as harmless scrap metal by a recycling inspector. County officials believe the chlorine inside had been used to disinfect food supplies.
Ron Rushing, owner of Tulare Iron and Metal, declined to comment about the accident. The California Division of Occupational Safety and Health has fined the company $15,000 for failing to make certain that containers do not contain hazardous materials and for failing to properly train workers. The company is appealing the fine. Records from Tulare County and federal courts do not show any lawsuits filed against the company related to the accident.
Most of the injured employees are back to work – but they are not back to normal.
Six months after the accident, "19 people were still seeing a physician for problems related to the chlorine release," said Dr. Rachel Roisman, a California Dept. of Public Health medical officer who worked on a health assessment of the workers with county officials.
People reported shortness of breath, change in sense of smell, headache, congestion or phlegm, dizziness, light-headedness and chest pain and tightness.
"Some people were still very affected by the incident either physically and/or psychologically. It had been a significant event for them. For some people, it was definitely still with them," Roisman said.