... having been breathed out

First enacted in 1912 [in Saskatchewan], An Act to Prevent the Employment of Female Labour in Certain Capacities is politely titled in racially neutral phraseology. The actual text, drafted in rather ponderous prose, reads: 'No person shall employ in any capacity any white woman or girl or permit any white woman or girl to reside or lodge in or to work in or, save as a bona fide customer in a public apartment thereof only, to frequent any restaurant, laundry, or other place of business or amusement owned, kept, or managed by any Japanese, Chinese, or other Oriental person.' The statute is anything but racially neutral in its text, with the Japanese, Chinese, and 'other Oriental' communities explicitly targeted because of their race. The designated female group is also defined by race, as the prohibition is expressly restricted to 'white women.' Prior to this act, most racial designations in Canadian statutes purported to classify peoples of colour. Various enactments dealt with 'Indians,' 'coloured people,' the 'Chinese, Japanese, and Hindu.' Racial designations in law are typically assigned by whites to non-whites. While the property of 'whiteness' is clearly a definable asset from which all manner of privilege and power flows, it usually tends to disappear into invisibility in legal terminology. The 'White Women's Labour Law' thus constitutes a rather startling development. It appears to mark the first overt racial recognition of 'whiteness' in Canadian law.

—Constance Backhouse, Colour-Coded: A Legal History of Racism in Canada, 1900-1950

The so-called White Women's Labour Law was backed by a coalition of (a) all-white, nationalist trade unions looking to make it more difficult for Asian business owners to compete with white business owners, and (b) Protestant evangelical moral crusaders and white feminist women's groups trafficking in racist hysteria about the supposedly devious, weak and asexual Chinese male employer looking to push white female employees into the arms of opium addiction. It was actually even more restrictive than it seemed: while Asian employers were ostensibly left their pick of employees from the pool of white men and non-white women and girls, in practice the high wages commanded by white men priced them out of the market, First Nations people were largely unavailable due to their geographic isolation, and racist immigration restrictions limited the numbers of Chinese and other women (and men, but particularly women) of colour. So this law severely hampered Asian business owners' ability to operate at all, while also decreasing economic opportunities for the white women it purported to protect. The Saskatchewan law was quickly followed up by similar laws, or discussions of similar laws, in other provinces:

The province of Manitoba was so impressed by the Saskatchewan initiative that it adopted identical legislation on 15 February 1913. Due to opposition from the Chinese community, the law was never proclaimed. In 1914, the Ontario legislature passed a similar enactment, although it was not proclaimed until 1920. British Columbia sallied forth with its own version of the 'White Women's Labour Law' in 1919. In Alberta and Quebec, despite expressions of interest, no such act was passed. There was discussion from Nova Scotia municipal politicians about drafting a similar measure, but nothing came to fruition in the Atlantic provinces either.

ETA: The more I think about this, the more what stands out to me between the lines is that there was plainly a very activated, politically organized presence in the Chinese Canadian communities in many of these provinces, in order for so many of these initiatives to have been scuttled due to opposition. That is a VERY impressive result, when you think about all the other institutional obstacles these folks were facing (including immigration quotas that artificially limited their numbers), and about the strong coalition of political forces that were allied against them. At the same time, it also makes me think about the amount of mental/emotional/political/energetic space that it must have taken to mobilize against these kinds of initiatives as they were sweeping from province to province. The fact that so many of them were not proclaimed is a testament to the organizing ability of the Chinese Canadian population, but even in provinces where things only reached the "discussion" phase (as in Nova Scotia, Alberta, and Quebec), energy was no doubt still required to prevent them going any further. And that's energy that these people were unable to expend on whatever they would have been pursuing if they'd lived in a less hostile environment.