Reassessment of the Response to Rail Safety Recommendation R02-01 – R99T0256
The Transportation Safety Board of Canada recommends that the Department of Transport review the classification and safety marks for anhydrous ammonia to ensure that it is in a class and division consistent with the risks it poses to the public.
|
Rail transportation safety investigation report
|
|
|---|---|
| Date the recommendation was issued |
|
| Date of the latest response |
October 2006
|
| Date of the latest assessment |
February 2008
|
| Rating of the latest response |
Fully Satisfactory
|
| File status |
Closed
|
Summary of the occurrence
At 1311 eastern daylight time on 23 September 1999, Canadian National freight train M304-41-21, destined for Toronto, Ontario, derailed 26 cars near the north siding switch at Mowat, near Britt, Ontario. The derailed equipment included 14 residue tank cars loaded with anhydrous ammonia. A loaded Liquefied Petroleum Gas (LPG) car and one anhydrous ammonia car were breached, each releasing product and igniting, resulting in several fires. At 1348, the loaded car of LPG exploded, projecting pieces of its tank and jacket in all directions. Approximately 127 000 pounds of LPG and 158 000 pounds of anhydrous ammonia were released. All the LPG and a large amount of the anhydrous ammonia were consumed by fire. The train crew was not injured; however, an Ontario Provincial Police officer, a local woodcutter, and two firemen suffered minor injuries as a result of contact with ammonia vapours.
The Board concluded its investigation and released report R99T0256 on 25 June 2002.
Rationale for the recommendation
The safety mark (i.e., green placard) presently required for bulk shipments of anhydrous ammonia can be misinterpreted, thus increasing the risk to the public. The green colour, which is used with products such as compressed air, is frequently interpreted to mean a product with lower risk, whereas the white colour, which was previously used for anhydrous ammonia, is associated with products that pose a higher risk. First responders such as fire-fighters and police in small communities, with little exposure to dangerous goods, may incorrectly make their first estimates of danger based in part on the colour and shape of a placard, instead of relying on the specific characteristics of the product. Therefore, the Board recommends that:
The Department of Transport review the classification and safety marks for anhydrous ammonia to ensure that it is in a class and division consistent with the risks it poses to the public.
TSB Recommendation R02-01
Previous responses and assessments
January 2003: Board Assessment of Response to 02-01
TC believes that the words "Anhydrous Ammonia" and "Inhalation Hazard" written on the tank car provide sufficient information on the nature of the product. However, the current TDG regulations no longer contain a specific requirement to stencil the words "Anhydrous Ammonia" and "Inhalation Hazard". The requirement for stenciling "Anhydrous Ammonia" is contained in the US Code of Federal Regulations, while "Inhalation Hazard" is mentioned in the CGSB Standard CAN/CGB – 43.147.
The Board does not intend to suggest that a placard is the sole source of information. Our recommendation addressed the issue of a possible misinterpretation by first responders who have had little exposure to dangerous goods, such as firefighters and police in small communities, or the general public. They may incorrectly make their first determination of danger based in part on the colour and shape of a placard, instead of relying on the specific characteristics of the product.
TC reviewed the classification and safety marks for anhydrous ammonia as recommended. TC acknowledges that the United Nations (UN) classification of Class 2.3(8) (toxic gas) is appropriate for anhydrous ammonia, despite being classified as 2.2 (8) (not-flammable, non-toxic gas). However, no specific action has been taken to reclassify this product. TC indicated that they will further consider the classification of anhydrous ammonia and they raised the matter at a meeting of the Federal-Provincial Task Force and also with the Minister's Advisory Council on the Transportation of Dangerous Goods. In addition, meetings were planned with fire departments to reconfirm their knowledge of the toxic and flammable characteristics of anhydrous ammonia. However, the ambiguity created by having a product with toxic characteristics being associated with less harmful products still exists. The response to Recommendation R02-01 was assessed as being "Satisfactory in part".
The Board followed up with TC to determine what further action would be implemented.
This file was assigned an "active" status.
June 2004: Response to R02-01
TC indicated their intension to proceed with an amendment to the TDG Regulations which would reclassify anhydrous ammonia to class 2.3(8). Transport Canada has also consulted the USDOPT on the proposed change in classification and they do not foresee any immediate obstacles in cross border movements.
December 2005: Board Reassessment of Response to R02-01 (Satisfactory Intent)
Based on TC's intent to amend the TDG Regulations, the response was reassessed as "Satisfactory Intent".
Next TSB Action
The Board followed up with TC to determine what action will be implemented.
This file was assigned an "active" status.
July 2006: Response to R02-01
TC forwarded an update which stated that TC is proceeding with an amendment to the TDG Regulations reclassifying anhydrous ammonia to class 2.3(8). The amendment is expected to be published in Part 1 of the Canada Gazette in Summer 2006.
This recommendation remains open for TC.
Latest response and assessment
October 2006: Board Reassessment of Response to R02-01
With the publication of the amendment, in Part I of the Gazette on 30 September 2006, TC's response can now be assessed as "Fully Satisfactory".
February 2008: Response to R02-01
Amendments to the TDG regulations have been finalized and made effective on 20 February 2008, which reclassifies Anhydrous Ammonia as Toxic gas Class 2.3, Subclass 8, Corrosive.
File status
Next TSB Action
The amendments have been finalized and the Board considers that further action is unwarranted and the status of this assessment response is changed to "Inactive"