| It looks like someone declared June 8, 2007 | | | | of Interest, to 6 CFR part 27. Cooling |
| to be the day for serious Anhydrous Ammonia | | | | systems having more than 7,500 pounds of |
| spills from refrigeration systems across the | | | | Anhydrous Ammonia in the system would make |
| country. There were three separate instances | | | | that food processing company a ?Chemical |
| of significant spills reported today. Mount | | | | Facility? under the rules of this regulation. |
| Sterling, KY, Wyalusing, PA, and Milwaukie, | | | | |
| OR all had releases in the last 24 hours. No | | | | According to the EPA Risk Management Plan |
| one was killed, but a number of people were | | | | (RMP) guidance documents, 7,500 lbs of |
| taken to the hospital, businesses were | | | | Anhydrous Ammonia released in 10 minutes time |
| evacuated, and residents were told to shelter | | | | from a pressurized system (clearly a |
| in place. | | | | catastrophic leak, not a faulty valve) will |
| | | | have a plume with a toxic end point 3.2 miles |
| There were explosions associated with two of | | | | down wind from the site of the leak (Table 9, |
| the incidents. There are reports that the | | | | 1.5 m/s wind speed). That means that anyone |
| ammonia leak at a Nestle Plant in Kentucky | | | | between the leak and 3.2 miles downwind could |
| caused an explosion that blew down a wall at | | | | be exposed to dangerous concentrations of |
| that plant; no injuries from the explosion or | | | | Anhydrous Ammonia. |
| falling debris have been reported. The | | | | |
| American Cold Storage facility in Oregon had | | | | Rather obviously, from the lack of |
| an unexplained (as yet) explosion result in | | | | casualties, none of these three release |
| the ammonia leak. There were no reports of an | | | | events came any where near 7,500 lbs in 10 |
| explosion associated with the leak at Cargill | | | | minute release rate required for a 3.2 mile |
| Taylor Beef Plant in Pennsylvania. | | | | long toxic plume. There is nothing in any of |
| | | | the available article that tells anything |
| Anhydrous Ammonia is favored in many large | | | | about the release rate for these accidents, |
| cooling systems because it has better heat | | | | but from the description they did not seem to |
| transfer characteristics and is cheaper than | | | | be catastrophic release events. But what |
| the refrigerant gasses used in home cooling | | | | about the explosion caused by the release in |
| systems and refrigerators. The problem is | | | | Kentucky? |
| that this material is very reactive and is | | | | |
| classified as a Toxic by Inhalation gas. | | | | Anhydrous Ammonia is a very reactive |
| Fortunately, the gas is extremely irritating | | | | chemical, and even by itself can form an |
| at well below the toxic level so that when a | | | | explosive mixture when mixed with air at |
| minor leak happens, unprotected people | | | | concentrations of 16 to 25% Ammonia in air, |
| evacuate the area quickly with little urging. | | | | though it would require a strong ignition |
| A catastrophic leak, however, can overcome | | | | source. It reacts to produce explosive |
| people before they have a chance to get | | | | by-products when it mixes with Chlorine, |
| clear. This is partially because many people | | | | Bromine or Iodine. Violent reactions occur |
| are temporarily blinded by less than lethal | | | | with Bleach or Peroxides. It also forms |
| concentrations. | | | | explosive compounds with Gold, Silver and |
| | | | Mercury. So, while explosions are not part of |
| The food industry has long maintained that | | | | the normal operating conditions of |
| they should not have to comply with any | | | | refrigeration systems using Anhydrous Ammonia |
| handling restrictions on Anhydrous Ammonia | | | | as a refrigerant, an explosion after a |
| required under various Federal laws, since | | | | significant leak would not be totally |
| they don?t actually handle Anhydrous Ammonia; | | | | unexpected. |
| it stays in a closed system. During the | | | | |
| regulatory comment period they complained | | | | Just maybe, DHS was correct in setting the |
| about being required to submit information | | | | STQ limit for Anhydrous Ammonia at a low |
| under the new Chemical Facility | | | | enough level so that some refrigeration plant |
| Anti-terrorism standards based on the 7,500 | | | | users could be labeled as Chemical |
| pound Screening Threshold Quantity (STQ) | | | | Facilities. |
| listed in the proposed Appendix A, Chemicals | | | | |