Menstrual blood is not just a physical substance; it is laden with symbolism and often powerfully stigmatised. It is important to understand local perceptions and attitudes towards menstrual blood, as well as the preferred practices of menstruating women, in order to design appropriate sanitation and solid waste systems to support menstruation. Failure to take account of socio-cultural factors can jeopardise the effectiveness of such infrastructure. This study, conducted in Blantyre, Malawi, is a qualitative socio-cultural examination of how women manage and view menstruation. Thirty nine interviews, conducted with individuals and with small groups of friends, were carried out with thirty one women using pit latrines, flush toilets, and urine-diverting dry toilets in early 2019. Menstruation in Blantyre was found to be shrouded in secrecy because it was viewed as 'dirty', and therefore remained concealed. There was widespread anxiety about menstrual blood being used in ufiti (witchcraft), which affected how women used and disposed of their menstrual absorbents. At the same time, menstrual blood was also viewed as a powerful healing substance with uses in traditional medicine. The type of infrastructure required by women to support their menstruation depended on the type of menstrual absorbent used. Those using reusable cloth generally preferred a private bathroom with discreet drainage, whilst those using disposable pads needed a discreet and convenient disposal system. Increased preference for disposable pads over reusable cloth (particularly for younger women in education or employment) suggested that menstrual waste profiles of urban areas may be changing. Understanding these changing needs will be crucial for planning effective, sustainable waste disposal and sanitation infrastructure.

The interplay between menstrual waste and urban sanitation infrastructure is largely hidden from view. Qualitative research has highlighted socio-cultural aspects of menstruation, but few quantitative studies have mapped the physical situation at scale. This study surveyed 258 women in Blantyre, Malawi about their menstrual absorbent choices, disposal practices, and sociodemographic characteristics. A Sankey diagram visualised flows of menstrual waste in the urban environment and identified ultimate disposal points. Most participants used either disposable pads and/or old cloth and disposed of them by either burning and/or throwing in pit latrines. Pad and cloth use were associated with age, education, employment, marital status, and household wealth. Younger women's preference for disposable pads suggests that demographic shifts may cause volumes of menstrual waste to increase. However, differences in waste volume produced by disposable and reusable absorbents was less than previously assumed. The volume of menstrual waste discarded in pit latrines, and cultural barriers to disposing it elsewhere, highlights challenges for the pit emptying industry and faecal sludge value recovery sector, with the problem anticipated to be most acute in high-density settlements. Widening access to sustainable disposal strategies, affordable reusable menstrual products, and tackling stigma, are key to addressing this social and environmental challenge.