"No girl should be missing school because she can’t afford to have a period," said Amika George, starting a movement with the #FreePeriods protest.  

And she’s completely right, of course. But the issue goes way deeper. Women have the right to dignity in menstruation in every situation, and no public body should be failing to respect and fulfil this right. But they are.

The next battle in the war for menstrual justice is taking place in police cells.

Today, police custody watchdog ICVA released a report showing that police custody in England and Wales is falling short of human rights standards for women on their periods.

Inspections have uncovered systematic failures to ensure that women on their periods have access to safe and adequate menstrual protection, or dignified conditions in which to change.

In 2016, the ICVA received a report of a woman in a police cell who had her clothes removed and was dressed in a paper suit.

Her underwear had been removed even though she had her period, and she was refused underwear on the grounds that she was at risk of self-harm.

No tampon was offered, and use of a pad was impossible without underwear.  She was left in a state of vulnerability, bleeding in a paper suit, alone in a cell.

“Dignity in the cells must mean dignity for all. Period.

“No woman or girl should be left bleeding in a cell in indignity simply for want of a difficult conversation or an inexpensive box of tampons,” says Katie Kempen, the ICVA’s Chief Executive.

Some police forces meet a high standard but, in the custody of others, women are unable to speak to a female officer, are not automatically offered period protection, or are offered inadequate or inappropriate protection.

There is “substantial evidence that the needs of menstruating women are frequently overlooked in police custody, placing the dignity of women and girls at significant risk,” say Caoifhionn Gallagher QC and Angela Patrick (Doughty Street Chambers), in their legal opinion, published by the ICVA today.

In some cases, women do not have access to a private place to change their pads or tampons, or to a sink to wash their hands. CCTV is sometimes not even pixelated around cell toilets.

What is clear is that new and stronger guidelines are needed: without clear statutory guidance, women and girls will continue to be left without period protection, in violation of their rights.

The ICVA are now calling on Home Secretary Amber Rudd and Minister for Women and Equalities Justine Greening to conduct a full review of this guidance, in view of the Equality Act 2010. They want urgent change to existing codes of practice, including the Police and Criminal Evidence Act 1984.

Menstruating women are oppressed in myriad often-subtle ways, which can cause social and economic damage, as well as psychological trauma to women in vulnerable situations. 

“Women’s rights are human rights, and that includes the rights of the most vulnerable women in custody. No-one should feel ashamed, no-one should be left in indignity,” said Baroness Shami Chakrabarti, Shadow Attorney General.

For more information about the ICVA's campaign and the experiences of menstruators in custody, read this Buzzfeed UK exclusive.