Girls who lack access to sanitary pads may miss up to 40 days of school a year. Photo: Cassandra Nelson/Mercy Corps.

In the United States, missing close to two months of school every year might get you expelled. For millions of women and girls in the developing world, it's a routine.

They lack access to something many modern women in the developed world probably take for granted: sanitary pads. Even when pads are locally available, many girls simply can’t afford them: UPI reports that in South Africa, a pack of 10 might cost $2. In many areas, that is more than a day’s worth of wages, according to North Carolina State University. Girls who don’t have access to pads during their period miss school due to embarrassment, fear of being teased and cultural taboos. Some try to use newspaper, old rags, or mud instead, methods that pose health risks and barely even work.

Many girls fall behind in school or drop out entirely as a result of this simple problem. For a variety of reasons, it’s one that’s not often discussed openly. So how do you solve a problem that no one wants to talk about? Fortunately, many businesses and organizations are looking for solutions.

At the same time that FemCare, a part of Procter & Gamble, sells Always-brand sanitary pads in U.S. supermarkets, it seeks to provide the same products to African schoolgirls. But the problem is thornier than you might expect. Beyond a simple lack of supplies, schools also often lack the facilities that allow girls to use feminine products in the first place. They need private spaces to change pads during the day and running water to wash their hands. To address this, FemCare built bathrooms and constructed water pipelines to schools, says the New York Times. They also provide disposal containers and have taught teachers how to incinerate the waste. Of course, there’s something in it for P&G, too: they hope that girls in Africa will become lifelong users of their products.

The problem has also inspired a great deal of innovation as individuals attempt to design new products that can be manufactured more cheaply and sustainably than name brands. Swedish university students used water hyacinth, an invasive species that chokes off Kenyan water routes, to create the Jani pad. In a double whammy, It’s both biodegradable and made from a seemingly endless resource that no one likes.

Starting in 2008, Sustainable Health Enterprises (SHE) tried another tack: it designed a manufacturing process that anyone could replicate. Their award-winning approach makes pads from readily available materials like banana-stalk fibers, which are then processed on inexpensive machines that local people can purchase. Hopefully, SHE’s innovations will better enable people in developing nations to start their own businesses to manufacture the pads. This also lets the finished product be tailored to the needs of women and girls from diverse cultures.

Other projects are born from the creativity of local entrepreneurs. Makapads, invented by a university professor in Uganda, are made from papyrus and waste paper and produced on locally manufactured machines, reports IRIN.

Often, trying to solve a problem in the developing world is like trying to solve a Rubik’s cube. Each group toggles the pieces a bit differently. Hopefully, in the end, someone makes them all line up.

Adolescent girls in developing countries miss up to 50 days of school each year because their families can't afford to buy them sanitary pads.

Fortunately, a start-up called Sustainable Health Enterprises (or the cleverly abbreviated SHE) is working to reverse this trend by helping Rwandan women start their own low-cost sanitary pad businesses. SHE is helping girls stay in school and increasing their potential earning power in the process. One additional year of primary school for a girl means a 10-20 percent increase in her future wages, according to a Council on Foreign Relations study.

This short, eye-catching video explains why SHE is doing the work that it does... The music's great, too.