What Is Humanitarian Sanitation and FSM? Why Is it Important?

Humanitarian sanitation refers to the provision of sanitation facilities and services for the safe disposal of human urine and faeces in a humanitarian setting. Faecal Sludge Management (FSM) encompasses the safe management of on-site sanitation facilities, i.e. the containment, emptying, transport, treatment and disposal or reuse of faecal sludge.


Access to safe sanitation and FSM services is important to reduce the spread of diseases, such as diarrhoea, cholera and other waterborne diseases, and to reduce the environmental impact (such as potential contamination of groundwater and surface water sources). Effective sanitation and FSM services can help to increase people’s productivity, maintain their dignity and safe lives. People in need of humanitarian assistance are often more vulnerable and, therefore, humanitarian sanitation services are even more important. 


There are several definitions of sanitation. Here, sanitation is defined as a multi-step process in which human urine and faeces are managed from the point of generation to the point of use or ultimate disposal. The term environmental sanitation refers to a wider sanitation definition including greywater management, solid waste management, drainage and vector control. 

A safe sanitation system is a system designed and used to separate human excreta from human contact at all steps of the sanitation service chain from the toilet (capture and containment) through emptying, transport, treatment (in-situ or off-site) and final disposal or end use (WHO 2018). The further management of sludge generated in on-site sanitation systems (and that is not transported through a sewer) is referred to as FSM. Faecal sludge is the mixture of human urine and faeces, water and solid waste (such as toilet paper) that is collected by on-site sanitation systems. 

During a crisis, sanitation services are often disrupted and humanitarian actors must rapidly re-establish or replace them. Moreover, crises often happen where sanitation services are already insufficient. According to WHO, in 2020, 54% of the global population (4.2 billion people) used safely managed sanitation services; 34% (2.6 billion people) used private sanitation facilities connected to sewers from which wastewater was treated; 20% (1.6 billion people) used toilets or latrines where excreta was safely disposed of in situ and 78% of the world’s population (6.1 billion people) used at least a basic sanitation service. Some 829,000 people in low- and middle-income countries die as a result of inadequate water, sanitation and hygiene each year, representing 60% of total diarrhoeal deaths. Poor sanitation is believed to be the main cause in some 432,000 of these deaths and is a major factor in several neglected tropical diseases, including intestinal worms, schistosomiasis, and trachoma. Diarrhoea remains a major killer but is largely preventable and providing improved water, sanitation, and hygiene could prevent the deaths of 297,000 children aged under 5 years each year. Poor sanitation also contributes to malnutrition (WHO 2018).  

WHO further describes how safely managed sanitation services bring many benefits in addition to reducing the occurrence of diarrhoea, including:   

  • reducing the spread of intestinal worms, schistosomiasis and trachoma, which are neglected tropical diseases that cause suffering for millions 
  • reducing the severity and impact of malnutrition 
  • promoting dignity and boosting safety, particularly among women and girls 
  • promoting school attendance: girls’ school attendance is particularly boosted by the provision of separate sanitary facilities 
  • reducing the spread of antimicrobial resistance;  
  • potential recovery of water, renewable energy and nutrients from faecal waste; and 
  • protecting the environment and natural resources. 

It was also found in a 2012 WHO study that for every US$ 1.00 invested in sanitation, there was a return of US$ 5.50 in lower health costs, more productivity and fewer premature deaths. 

In the humanitarian context, off-site FSM is not always required. The WASH cluster FSM TWiG considers that if households have access to a private latrine and fulfil the following three key conditions, the sanitation system is considered safe: (1) the groundwater table is 1.5m or deeper (vertical) than the bottom of the pit/tank; (2) the latrine/pit/tank is 30m or more (horizontal) from a water source and (3) there is sufficient space to dig a new pit/tank and safely decommission when the pit/tank is full. Whilst this is often the case in rural contexts, in other contexts such as crowded refugee camps, urban contexts and where the ground water table is high and the above-mentioned conditions cannot be achieved, a sanitation service chain is required to provide a safe sanitation system.  

When toilets are connected to a sewer, the sanitation service chain consists of toilets and the sewer network transporting wastewater to the wastewater treatment plant. This requires higher investment and skills as well as increased operation and maintenance costs compared to FSM. There are many different technologies for each step of the FSM service chain (see e.g. the Compendium of Sanitation Technologies in Emergencies) and, if all steps are adequately managed, FSM can be an economical, sustainable and long-term solution.  

FSM must be distinguished from wastewater management. The term wastewater is generally used to refer to the mixture collected in and transported through a sewer system, using flushing water to transport faeces and urine and it may also contain greywater (the water from e.g. showers and sinks). Faecal sludge is the mixture of human urine and faeces, water and solid waste (such as toilet paper) that gets collected in onsite sanitation systems and is not transported through a sewer. Faecal sludge is very different to wastewater and their management implies different technologies, resources and constraints. In some situations, the differences are not so clear (e.g. very liquid sludge or very dense wastewater) and the characterisation of the sludge to be treated becomes fundamental. It is worthwhile to understand that wastewater can be a by-product of sludge treatment and sewage sludge can be a by-product of wastewater treatment. 

Process & Good Practice

  • Consider the entire sanitation service chain when planning and implementing humanitarian sanitation/FSM interventions 
  • Consult and engage the users of sanitation facilities through the entire sanitation service chain 
  • Ensure that the sanitation services are rapidly functional and sustainable in the long term 
  • Plan and implement a phased approach, starting with public health protection as a priority, and moving towards a focus on user satisfaction and environmental protection later on 
  • Ensure national regulations and relevant standards are complied with along the sanitation service chain  
Shirish Singh
IHE Delft Institute for Water Education
Reviewer(s) / Contributor(s)
Alberto Acquistapace
Solidarité International (SI)
Marij Zwart
Netherlands Red Cross (NLRC)
Rob Gensch
German Toilet Organization (GTO)

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