McKay’s Choice? Investigating Arsenic in 19th-Century Canadian Wallpaper
by Timothy Greening
Featured in Ornamentum Spring/Summer 2026 issue
Wallpaper is an often-overlooked form of decorative art. The earliest European wallpaper is from the sixteenth century, when it decorated the interiors of cupboards and chests with designs drawn from tapestries, embroidery motifs, and textile patterns. Mid-eighteenth-century developments in European printing technology allowed for the commercial production of wallpaper in multicoloured designs. In the nineteenth century, continuous printing on large paper rolls greatly expanded the market for wallpaper.
Much more than an unassuming backdrop in historic homes, Victorian era wallpaper (c.1850-1900) often has a hidden hazard. Although several pigments in period papers are dangerous due to their lead content, the main culprit for acute toxicity is arsenic. Arsenic compounds pigmented many of the new, vivid colours of the time. Typical of the era is Paris, or Emerald green, a poisonous but popular formulation of copper aceto-arsenite. Even when these papers first appeared, health care practitioners raised the alarm about the negative impacts wallpaper might have on public health—a concern that is well documented in contemporary literature from America and England. Particles of green pigment that flake off or vaporize in humid conditions are harmful if they enter the body. Particularly at risk are young children, who could easily ingest arsenic rubbed off on the hand. This green can remain hazardous wherever wallpaper from this period is found, so it is an important research topic at Parks Canada’s Conservation Science laboratories.
Parks Canada cares for a collection of approximately 31 million historical and archaeological objects, representing over 11,000 years of Canada’s past. The national parks and historic sites under its purview frequently exhibit the objects under its care. The Conservation Science team contributes to the care of this collection by offering scientific analysis that informs strategies for risk reduction and heritage protection. Once the team identifies an artifact as hazardous, proper safety procedures apply to the safe handling of the papers. The Hazardous Object Guidelines (HOGs) are a series of evergreen procedural documents produced by the Preventive Conservation team of the Indigenous Stewardship and Cultural Heritage Directorate at Parks Canada that enable us to safely care for these artifacts into the future. However, the question remains, what was the Canadian experience during the era of contaminated wallpaper?
Canada’s Wallpaper and “McKay’s Choice”
Canada was in an interesting position for its interior decoration trends during this period, importing both American, French, and English wallpapers, as well as producing and exporting its own designs. For example, New Zealand has documented swatches of Canadian-made wallpaper in their archives (Figure 1). However, a lot of Canadian wallpaper was imported. For example, W.M. McKay’s, a wallpaper retailer in Ottawa, advertised in 1875 that they directly imported choice and beautiful papers from England, France, and the United States. Although interesting, what truly grabs our attention in the advert is the promise that the papers sold “are free from the mineral poisons that many of the tawdry coloured paperhangings of the day are surcharged with. The subscriber’s long experience . . . enables him to reject . . . poisonous pigments so deleterious to health.” This claim suggests that distributors sold poisonous wallpapers in Canada and that they caused a negative impact on public health.
Pigment Catalogues: A Smoking Gun
The 1897 catalogue from Montreal-based paint manufacturer P.D. Dods and Co., Island City Varnish, Paint and Colour Works: Catalogue and Price, is an excellent primary source to understand the state of pigment choices in the production of wallpaper at the turn-of-the-century. The company sold Paris green as a “Government standard” product in casks and “arsenic kegs” of 50- and 100-pound drums or buckets, and one- or half-pound packages in 100-pound cases. The large volumes and standardized label point to its use as a pesticide. Before the invention of DDT, arsenic was widely employed as an insecticide and rat poison, both in town and country.
But the catalogue also lists a ready-made oil paint of Paris green at the reasonable price of 25 cents per pound. For comparison, the cheapest ochres and browns were from 12-18 cents a pound, and azure blue and genuine vermilion were 35 and 46 cents a pound respectively. It is worth remembering that difficulty in grinding and oil adsorption rates affected the price of a prepared oil paint. In England, the colour Paris green was called Emerald green when formulated as an artist pigment or wallpaper colour. Adding to the confusion, by the end of the nineteenth century some also applied the name Emerald green to a synthetic lake colour.
Nineteenth-century wallpaper manufacturers typically used paint in a distemper medium (animal glue) to print the papers. The P.D. Dods catalogue of distemper colours for wallpaper provides a snapshot into the colour formulations used to pattern Canadian wallpapers (Figure 2). What is meant by the term Emerald green on this list? The page also contains a category of “lakes”—substances formed by precipitating a water-soluble dye with an insoluble material to produce a solid colorant. The table includes green lake with other lake colours, most of which were aniline dyes. Lakes are on the pricier end of the colour series. Since green lake was more than three times the price of Emerald green, we can assume this distemper colour did not contain arsenic. At 40 cents per pound Emerald green was an economical choice, which was no doubt a deciding factor for wallpaper printers.
By the twentieth century, poisonous colours such as Paris/Emerald green and red and white lead are absent in wallpaper. But from the P.D. Dods catalogue, we can conclude that Paris green was still sold in Canada as a wallpaper pigment decades after it was a health crisis in both England and the United States.
Current Affairs Meets History
Also informative is how changes in import fees affected the choice of pigments for historical wallpaper manufacture. Paris green was duty free for Canadian wallpaper manufacturers starting in 1866. The government evidently saw continued demand for it and so exacted no levy.
However, by 1880 a tariff applied to imported Paris green. This charge did not have to do with health and safety—the government did not ban it even after these concerns became more widely known—but simply to protect the home-grown chemical industry.
Figures 4 and 5: The T. Eaton Co Limited, Wall Paper Samples 1912 cover and inside pages, Toronto, Canada. Paper, 14.5 x 19.5 x 0.5. EX.2011.19.271 Front Cover. © Parks Canada Agency. Photo: Timothy Greening
Not Just on Walls!
In past eras, wallpaper did more than decorate walls; it was also a crafting material. People often wallpapered objects such as chest, cabinet, and drawer interiors. One example is a now-destroyed wallpapered doll's box (Figure 3). This paper has a faux wood grain typical of the first half of the nineteenth century, although its pattern effect and colour choice are nowhere near a passable wood imitation but only a rough abstraction. A test of this wallpaper found a significant quantity of arsenic.
Additionally, the manufacturing and merchandising of wallpaper left behind artifacts that contain arsenic. It is surprising how much wallpaper exists today in institutions in the form of sample books, such as this stylish 1912 one from Eaton’s (Figures 4 and 5). Luckily, testing using our laboratory’s portable X-ray fluorescence analyzer confirmed the greens both inside and on the cover of this catalogue are arsenic-free. While the market for bright reds and greens in wallpaper continued into the twentieth century, changing technology, as well as public health pressures, meant that the demand for arsenic colours did not continue.
Made-in-Canada Arsenic Wallpaper?
As pointed out in 1875 by the proprietors of W.M. McKay’s, and documented through testing at the Parks Canada laboratory, there is arsenic green in wallpaper in Canada. Although a popular trade commodity, the question remains: Was arsenic wallpaper ever made in Canada? All evidence points to this being the case during the nineteenth century, particularly as we can confirm the availability of the offending materials from Canadian suppliers in that era. However, physical proof of made-in-Canada arsenic wallpaper remains elusive.
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Timothy Greening works as Archaeological scientist at the Parks Canada Agency. He holds a Master’s degree in Paintings conservation from Queens University and a Master’s degree in Technical Art History from University of Amsterdam.
This article appears in the Spring/Summer 2026 issue of Ornamentum magazine. To purchase the issue or subscribe, head to our store.
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