B-9 Operating conditions — Weather

Dangerous Goods

The issue of weather was raised following a series of road accidents where, in some cases, dangerous goods were involved.  We received newspaper clippings on some accidents and we  looked through our files for dangerous goods accidents where the weather was cited as a possible cause.

Here are summaries for six road accidents where dangerous goods were involved.  The first two are from the newspaper clippings received, the others are from our files.

Grande Prairie, AB, January 2004:  A trucker had stopped on the side of the road, near Smoky River Hill, to mount chains on his truck.  A cement truck hit the stopped truck and another truck sideswiped the pair.  Molten sulphur was spilled.  One driver was killed (because of the collision, not because of the release of sulphur).

Alaska Highway, Yukon/BC; January 2004:  An icy-road collision involving a propane truck caused an accidental release of the propane and, as described by RCMP officers, a giant fireball stretching across the road and shooting flames 15 metres high.  A stretch of the Alaska highway, over 1 km long, was closed for a while.

Moose Jaw, SK; April  2003: During transport in white out snow conditions a tractor trailer and pup containing gasoline went off road and overturned in a ditch releasing 320 liters of product from the tank trailer vents. There were no injuries.

New Sarepta, AB; December 2003: In a snow storm, a tractor trailer (tank: residue last containing nitrogen, refrigerated liquid) was involved in a head-on collision with a minivan. No release of product, and no damage to the tank. Three persons in the minivan died and one was injured (all from the collision, not the dangerous goods).

Ramore, ON; February 2002: In a snow storm, a tractor trailer containing a mixed load of packaged goods (some dangerous goods) was involved in an accident with five other tractor trailers. There was no release of product. Two persons were injured as a result of the collision.

Lundbreck, AB; March 2002: In snowy weather conditions a tractor tank trailer and pup containing diesel fuel went off the road and overturned in a ditch releasing 10 liters of product from the hatch. There were no injuries.

Is all bad weather “bad”?

One important element is to identify what component of the weather really causes concern.  For example, extreme cold can be a mixed blessing.  While it ices up the roads and accelerates mechanical failures, it also reduces chemical and physical hazards posed by many dangerous goods.  Heat is a major accelerator of chemical reactions.

There have been accidents in Canada where dangerous goods were released, yet the consequences remained minor because of the cold temperature.  In the two examples, the weather had an impact on consequences but was not a cause of the accident.

A decade ago, a rail tank car full of butane sprung a leak.  Because of the cold temperature, it was possible to recover the butane using the equivalent of a bucket and a mop.

Over two decade ago, a volatile powder that turns into a poisonous gas when exposed to humid air, was released when its container broke open while being unloaded.  The product fell to the snow-covered ground (more humidity).  However, no chemical reaction occurred.  The temperature was around -30°C and the powder just sat there.  It was eventually shovelled back (by well-suited workers) into an appropriate container and sent for neutralization.

A review of TDG accidents where the weather is a factor, points to poor visibility from precipitation and fog as the most probable link among accidents taking place while “bad” weather is occurring.  Most accidents where the weather is blamed occur after the bad weather is over.  The direct cause is therefore road conditions (icy, snow covered, etc.).


Over the six year period of 1998 to 2003 (inclusive), there were an estimated 160,000,000 shipments of dangerous goods, of which an estimated 140,000,000 were on a road vehicle for part or all of their transportation.

The total number of dangerous goods accidents reported during the six year period is 3282.  Of these, 156 where caused by some weather condition, of which 88 were “reportable accidents” involving dangerous goods transported on a road vehicle.  Reportable means that they met the conditions described in section 8.1 of the TDG Regulations.  That is an average of 15 per year for Canada.

In 60 cases, the weather made the roads bad (icy, snowy) and the road conditions were then blamed for the road accident.  In 28 cases, the accident is blamed on actual precipitation.

Year Total reported accidents all modes Total Weather
all modes
Weather: on road, reportable accidents Direct weather (precipitation, fog)
1998 508 29 18 3
1999 571 29 23 5
2000 612 22 16 10
2001 529 27 15 6
2002 546 17 9 2
2003 516 32 7 2
Total 3282 156 88 28

Year:  January to December.

Total reported accidents, all modes:  Includes accidents that are reportable (they meet thresholds described in section 8.1 of the TDG Regulations) and accidents for which a call was placed to CANUTEC.

Total Weather all modes:  Any reported accident where the weather was indicated as a possible cause of the accident.

Weather, on road, reportable accidents:  accidents that are reportable (section 8.1 of the TDG Regulations) and that occurred while the goods where in or on a road vehicle;  this includes all weather impacts, including icy roads after a storm is over.

Direct weather (precipitation, fog):  Reportable dangerous goods accidents that result from road accidents directly caused by weather.  The two accidents from 2002 and the two from 2003 are summarized in the examples at the start of this page.

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