Liability and property insurers will be interested to learn of the recent decision of the Ontario Superior Court of Justice in Tudor Inn Reception Hall (1992) Ltd v. Merzat Industries Ltd. where a products liability action brought by the plaintiff Inn was dismissed as against the defendants, the manufacturer and distributor of a product called "THE GREAT DESTROYER".

One of the grounds of dismissal was a recognition that the law of tort will not impose a duty to warn of a danger which is so obvious and apparent that anyone would be aware of it.

Background Facts

The plaintiff Tudor Inn provided catering and banquet services to the public. The president of the plaintiff, believing that a skunk was lurking under the men’s washroom in the back of the Inn, ignited a cartridge of a product called THE GREAT DESTROYER by suspending it on a clothes-hanger through an open 3" drainpipe under the washroom floor.

Some hours later, the smoking cartridge caught fire and burned down the Inn and its contents.

An action was brought against Atlas Chemical Corporation of Iowa, the manufacturer, and against Merzat Industries Ltd., the Canadian distributor of the product, in negligence, breach of contract and breach of statutory warranties and conditions under the Ontario Sale of Goods Act. The damages claimed were $1.5 million. Each package of the product contained four cartridges. Prominently displayed on the front of the package was the description:

"THE GIANT DESTROYER KILLS Ground hogs (woodchucks), moles, gophers, ground squirrels, skunks and rats in burrows and holes. THE EFFECTIVE GAS KILLER IN CARTRIDGE FORM ... WARNING – KEEP OUT OF THE REACH OF CHILDREN … See back of card for additional precautionary statements".

On the back of the package were directions how to use the product in pictures and words which clearly indicated that the product was to be used inside animal burrows in the earth.

Reminiscent of actor Bill Murray’s role as a golf course groundskeeper hunting groundhogs in the movie Caddy Shack, the directions demonstrated that one burrow entrance must be cleared and all other entrances sealed; the fuse was then inserted into the cartridge end. The fuse is then lit and the cartridge inserted into the opening.

There was an explicit warning on the back of the package:

"DIRECTIONS FOR USE: use only inside of burrows, never inside of buildings".

The directions for use on the back of the package contained a number of cautions, one of which provided:

"Once ignited by the fuse, this cartridge will burn vigorously until completely spent and is capable of causing severe burns to exposed skin and clothes and of igniting dry grass, leaves and other combustible materials".

Each cartridge of the product had its own warnings in red ink which included that the product was only to be used "inside of burrows and never inside of buildings".

During the course of the trial, the president of the plaintiff testified that he had used THE GREAT DESTROYER three times before this incident – twice outdoors at his cottage and residence and, once at the Inn – without a problem. He also acknowledged that he had read the instructions on the package and on the cartridge, and that the wooden frame and joists under the ceramic washroom floors at the Tudor Inn were combustible materials.

Conclusions on Liability

The court found that the fire was caused by the careless and reckless igniting of the cartridge by the plaintiff’s president who did so without determining the presence of combustible materials. The court also found that the president of the plaintiff ignored the explicit warnings on the package and on the cartridge, and in particular the words "ignition" and "combustion", which were clearly referable to the risk of fire. The court said:

"A person of ordinary prudence reading those words would have known or ought to have known that the use of the Product outside animal burrows in the manner depicted and described on the cartridge and the package was unsafe when, as in this case, the Product was used in proximity to combustible materials capable of being ignited and causing a fire."

In referring to the Supreme Court of Canada decision in Lambert v. Lastoplex Chemicals Co. Limited et al. the court concluded that the defendants’ words of warning as to fire risk were reasonably explicit, presented and communicated to a potential user of the Product and, satisfied the applicable standard of care.

As an alternate ground of the decision, the court said that:

"Quite apart from the issue of the adequacy of the words of warning, the law of tort will not impose a duty to warn of a danger which is so obvious and apparent that anyone would be aware of it".

The Ontario Superior Court of Justice cited with approval two prior appellate decisions including Deshane et al v. Deere Co., and Schulz v. Leeside Developments Ltd.

In Deshane, a forage harvester manufactured for intended use in field operations was modified and altered for stationary use. The danger posed by the employer’s modified use of the harvester was obvious and known to the employer and its employee. There was no duty imposed by law on the manufacturer to warn the customer of that danger.

In Schulz, the suppliers/renters of a V-hull fibreglass boat propelled by a 50 hp outboard motor had no duty to warn a seemingly capable and careful 18 year old person of the obvious danger of riding on the bow of the boat when it was travelling at full speed.

The following passage from Prosser’s Law of Torts, 4th Edition was approved in these decisions: 

"Obvious Dangers:

One limitation commonly placed upon the duty to warn, or for that matter the seller’s entire liability is that he is not liable for dangers that are known to the user, or are obvious to him, or are so commonly known that it can reasonably be assumed that the user will be familiar with them. Thus there is certainly no usual duty to warn the purchaser that a knife or an axe will cut, a match will take fire, dynamite will explode, or a hammer may mash a finger".

The court said that these words applied with equal force where the specific danger in this case, the risk of fire, arises from modified use of a product by a user contrary to explicit warnings which the user chose to ignore.

Other Cases: No Duty to Warn

There are two other authorities that should be noted in support of the proposition that there is no duty to warn of obvious and apparent danger that anyone would be aware of it. The first is Stiles v. Beckett and the second is Baker v. Suzuki.

In Stiles, the injured plaintiff suffered serious injuries when riding his 3 wheeled ATV at 40 mph without a helmet when it did a forward flip or summersault. The warnings on the ATV gave reasonably adequate notice of the need for caution and safe riding, and the plaintiff was already aware of the dangers which were the subject of the warnings. An expanded warning would not have altered the plaintiff’s behaviour.

In Baker, the plaintiff was injured after a frontal collision while operating a motorcycle led to a gasoline leak and fire. The court rejected as a basis of liability the allegation that the manufacturer failed in its duty to warn of the risk of fire injury associated with operating a motorcycle. The court said that the plaintiff would not have declined to ride the motorcycle because of that risk.


The Tudor Inn decision is only one of a handful of Canadian decisions over the last 30 years which supports the principle that the law of tort does not impose a duty to warn of a danger which is so obvious and apparent that anyone would be aware of it.

In considering whether this is a viable defence in any given case, reference should be made to all of the authorities discussed above.