The Secret Chemical Weapons Lab At Rideau Falls


An aerial photo of the Chemical Weapons Laboratory that used to be at Rideau Falls.

UPDATE: On October 24th 2016, one week after this article was originally posted, it was announced by the NCC that the site will now become location for Canada’s Centre for Geography and Exploration. The Centre is scheduled to open its doors in 2017 as a Confederation Pavilion during Canada’s 150th anniversary.

Being the Nation’s Capital, Ottawa has always been home to a number of government facilities working on classified projects. These “classified” government projects are developed in secrecy, with details about them not being revealed until years later, if at all. A scenic park beside Rideau Falls may seem like an unlikely spot where one of these projects occurred…but it did, and it was not just any project. It was a secret lab inside an old pulp and paper mill developing and testing chemical weapons.



The secret Chemical Weapons Lab at Rideau Falls that was once a pulp and paper mill. (Photo: Shirley’s Bay Review)

Allied forces during World War Two, including Canada, made preparations to wage both chemical and biological warfare. The use of chemical and biological weapons had already been experienced in the First World War with ghastly results. The threat of bio/chem weapons being used in WW2 was less of a concern due in part to the signing of the 1925 Geneva Protocol, a treaty prohibiting the use of chemical and biological weapons in international armed conflicts. Yet, here in Ottawa there was human experimentation involving volunteers at the wartime Chemical Weapons Laboratory in Ottawa to assess the effects of chemical agents as well as to develop protective measures.

A Chemical Weapons Laboratory.

In Ottawa.

What!? Where was this? you might ask…In some remote field miles south of the city in a secret facility?. No, rather it was a government building beside Rideau Falls that is now a scenic park owned by the NCC.


Current view of what used to be the Chemical Weapons Lab. (photo:Google)


The year was 1941 and the National Research Council (NRC) was part of program to study the use of choking gases such as chlorine, and chloropicrin in addition to the hellish compounds of hydrogen cyanide and cyanogen chloride. Ottawa’s studies also included blistering weapons such as the infamous mustard gas. It is hard to believe but labs in Canada studied, tested, manufactured and stockpiled these bio/chem weapons during World War 2. Research was headed by the Directorate of Chemical Warfare and Smoke and conducted in Canadian university labs using NRC grant programs. These school labs included McGill, Toronto, Queen’s, Saskatchewan and Western.


Manufacturing of chemical and biological weapons at Rideau Falls labs. (from “A Brief History of the Defence Research Establishment”)

Ottawa had its own Chemical Weapons Laboratory working with the NRC at Rideau falls in a now demolished facility. Created in 1940, the Rideau Falls Chemical Weapons Lab, dubbed “CWL” was responsible for the production of flame thrower fuel and the manufacture of 1000 pounds of B1 dye used to detect mustard gas in addition to a number of other “classified chemical compounds”. By the end of the war CWL had produced 8 million gas masks, forty million canisters, and in Cornwall, produced barrels of deadly mustard gas.

The Ottawa labs worked on highly toxic but largely unknown chemical agents. Once a converted pulp and paper mill known as Edward Mills, the secret labs operated from 1940 until 1947 when operations were moved out of the Rideau Falls site to Shirley’s Bay. The labs were soon demolished after the move-out and were eventually made into Rideau Falls Park which is there today.


The John Street Labs, classified as “Chemical Weapons Laboratory, CWL” (photo: geoOttawa)

In addition to the study, testing and manufacture of bio/chem weapons and the associated gear to counteract them, the CWL labs at Rideau Falls also conducted experiments on volunteer subjects. Paid volunteers would be subjected to testing of chemical agents, with experimental counter measures being tested for their success. Subjects suffered blisters, and respiratory testing. In February 2004, the Ministers of National Defence and Veterans Affairs announced a recognition program to offer payments to these Canadian veterans who volunteered to participate in chemical-warfare experiments in Ottawa and elsewhere.

After the Second World War, the stockpiled chemical and biological weapons were taken aboard ships and unceremoniously dumped into the Atlantic Ocean, where barrels upon barrels of these nightmarish compounds decay on the ocean floor.


The current site of what was once the grim Chemical Weapons Lab. (photo: Google Streetview)

The site that was once a shrouded chemical and biological weapons facility is now nothing but a tranquil NCC owned property called “Rideau Falls Park”. Here the NCC built the now abandoned Canada and the World Pavilion in 2001,  which subsequently was shuttered in 2005. It was announced on October 24th 2016 by The National Capital Commission and the Royal Canadian Geographical Society that the site will now become Canada’s Centre for Geography and Exploration. “The Centre is scheduled to open its doors in 2017 as a Confederation Pavilion during Canada’s 150th anniversary.” There is no mention of the shrouded past of the site other than a quip on the NCC website that states it was “developed after the Second World War when the area was acquired by the federal government and cleared of industry.”

What a gas.

Andrew King, October 2016


Click to access CanadaandChemicalWarfare.pdf

Click to access p518800.pdf Shirley’s Bay Review

Google Maps

“A Brief History of the Defence Research Establishment” published 2002






  1. Shocking to learn of this operation right in the heart of a Capital City !! It is also difficult to believe they could find their Volunteers to test it all on !! Ha! Very enjoyable report ! Thank you !!

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