In recent years there has been rising popular discourse around "toxic masculinity", and the problems of a hegemonic gender structure that facilitates male violence and misogyny. In the public debate over whether toxic masculinity is fact or fiction, "toxic femininity" is often raised by men's rights activists and others as an anti-feminist retort, to suggest that women can be "toxic" too. This paper provides a sketch of how the term has been used so far, in tandem with an overview of the limitations of the more extensively discussed idea of "toxic masculinity". This suggests that although the term "toxic femininity" has limitations, it is useful to consider what might be "toxic" about some approaches to femininity. Drawing on existing theories of femininity, including emphasized, hegemonic, normative, and patriarchal femininity, this paper offers the notion of "rigid femininities" to explain the attachments that keep us locked in a "toxic" gender system. This paper utilises toxic femininity as a starting point for theorising femininity broadly, to conceptualise the "toxic" attachments that reinforce the hegemonic patriarchal gender structure.