Mattress Study

This page examines DAC's mattress and foam research led by DAC's Materials Specialist

Problem Context

Although not technically classified as furniture, prison mattresses have been challenging and an item of particular importance for both prisoners and MoJ staff since the outset of our research. Our findings showed an overwhelming dislike for the prison mattresses in categories of comfort and durability. The current prison mattresses are made from a flexible Polyurethane (PU) foam (also known as FPF) covered with a vandal-resistant, wipe clean cover. They are reported to be extremely uncomfortable and deteriorate very quickly. The churn rate is so high that the MoJ purchases approximately 34,000 mattresses and 32,000 pillows per annum (see MoJ mattress specification document). This not only costs the MoJ a considerable amount, but uncomfortable mattresses cause prisoners to have poor sleep, which can be closely linked to health problems and an increase in volatile behaviour (Kamphis, Meerlo, Lancel, 2012).

Objective

Our aim was to find an alternative material that meets the technical and fire safety requirements of the current foam, while increasing the comfort for users and extending the lifespan of the product, making them more sustainable and cost effective by reducing replacement rates.

Research

The Problems We Want to Fix

The user experience, health problems and violent behaviour associated with bad physical support and poor sleep.
Technical aspects of the mattresses effecting lifespan and sustainability.
End of life protocol, and how we can increase recycling rates.

Our Design-Research Approach

Research of user-experiences via collaborative design workshops and interviews.
Visits to recycling and manufacturing plants of current mattress.
Review of sleep studies in custodial environments.
Investigation of new materials from other areas with heavy usage and fire safety standards such as hospitals, hotels, automotive and aerospace.
Fire testing with the University of Central Lancashire.

Research Findings

The MoJ team that we worked with was eager to improve mattress quality, and this is a view that we encountered many times over the project. It has also been mentioned formally in prison inspection reports, seen here in the report of HMP Barlinnie, 2016:

'The SPS should consider reviewing their mattress specification as the ones currently provided are thin and when compressed it was possible to feel the bed structure below. The pillows provided were very hard.' (HMIPS, 2016)

Looking to the prison population a search on Inside Times (prison news publication) reveals multiple articles and complaints referring to the mattresses, as per the example below:

'Most prisoners will be accustomed to back pain which is the inevitable result of sleeping on a wafer-thin prison mattress. Some prison mattresses are bot fit for human habitation.' (Anonymous, Inside Times, 2012)

Our initial interviews with returning citizens reiterated these points and we started hearing about particular health problems associated with the mattresses and how the inmates would try and mitigate these with the resources available:

"Lying on your side, you wake up and your shoulder and hips are aching. I'm sure many people got crippled from just sleeping on these beds. What we did was that we'd use the picture boards that we took off the wall to put under the mattress so it doesn't sink in. We'd cover the shoulder and hips area." (Returned Citizen Interview, 2018)

"Sometimes you see guys with two or three mattresses but they're all half an inch thick where they've been compressed and compressed and compressed over time." (Returned Citizen Interview, 2018)

The most common complaint we heard about the mattresses was that they start off very hard and then quickly compress with no rebound or memory, creating a very uneven, thin, and uncomfortable sleeping surface. This is particularly problematic in relation to the metal bed as the metal slats running horizontally and vertically on the bed base (i.e. a waffle pattern) cause the mattress to depress at a faster rate compared to the whitewood beds, whose bases are essentially solid sheets of MDF. As a result, the individual metal slats can be felt through the mattress.

Multiple participants at our workshop at HMP Standford Hill reported back pain from the mattress paired with the metal bed, and after the plastic chair, the combination was voted the ‘least favourite’ piece of furniture overall. The participants named comfort one of the things they would most like to improve and added comments about the bed and mattress:

"A comfortable bed and chair make life a bit better." (Prisoner Interview)

"A comfortable bed is very important as it makes you relax and chill out and can also calm people down; [for instance] forget problems, stop fighting and arguing." (Prisoner Interview)

The link between feeling calm and having a comfortable bed is important, as everyone can personally attest to how a bad night’s sleep can affect your mood and actions. Research shows that poor or disturbed sleep can be a factor in reactive aggression and violence. (Kamphis, Meerlo, Lancel, 2012). In the section below, we review research in this area and consider how it may be applied to improving the prison living environment.

Sleep and Prisons

There is strong evidence that sleep loss and sleep disorders have profound and widespread effects on human health (Colten, Altevogt, 2006), and there are many potential reasons for a poor night’s sleep in prison. Factors including loud and sustained noise, bright lights, unpleasant smells, anxiety and discomfort can all contribute to loss of sleep in a cell. In this project we are limited in how we might effect many of these disturbances with cell furniture, but we aim to improve one very important factor, the immediate sleep environment of the bed and mattress.

‘Many people have the experience that disturbed sleep is accompanied by... a greater irritability and short temperedness. In most people this will not result in physical outbursts of aggression. However, this may be different in vulnerable individuals. (Kamphis, Meerlo, Lancel, 2012).

For the general population we already know that poor quality and duration of sleep has a negative impact on physical and mental health (Matter, 2017). However the prison environment has a higher population percentage of vulnerable individuals and those suffering from mental health disorders. An Office for National Statistics study found that 7% of male prisoners have a psychotic illness compared with an overall figure of 0.5% in the general population (Nurse, Woodcock and Ormshy, 2003). With this higher level of vulnerability comes increased potential of physical outbursts as a result of disrupted sleep, which can ‘contribute to loss of control over emotions, including loss of the regulation of aggressive impulses to context appropriate behaviour’ (Kamphis, Meerlo, Lancel, 2012). In relation to young offenders, a UK study of sleep and violence in incarcerated adolescents between 16 and 18, carried out by Lousie Ireland and Vicky Culpin, found a ‘potential relationship between aggressions and sleep in incarcerated adolescent male sample, highlighting in particular a role for hostility.’ (Ireland, Culpin, 2006).

This violence can be directed at others or manifest through self-harm, Renee D. Goodwin and Andrej Marusic study a large sample of the general population and have found an ‘association between short sleep and suicidal ideation and suicidal attempts among adults in the community.’ (2008). They point out that people who report having mental disorders often also report having poor sleep, however people with pre-existing suicidal ideation have an increased risk of suicidal attempts after short sleep, because of associated risk of mood and panic attack. (Goodwin and Marusic, 2008).

A lack of sleep does not support rehabilitation, and as Kamphis et al. suggest, ‘the treatment of sleep problems may be a valuable, innovate element in aggression reducing and crime preventing treatment programs.’ The link between sleep loss and aggression and violence is proven and in prison this can affect the individual, the wing community, the officers, the prison establishment, and ultimately the carceral system. Improving mattress quality will not fix all the problems in the prison system that contribute to sleeplessness but a concerted effort to improve mattresses would provide a boon to prisoners and reflect a system that strives to rehabilitate rather than punish.

Current Prison Mattresses

The mattresses currently supplied to HMPPS are made from a foam with the tradename, Fireseal™, which is made in the UK by Carpenter, an American owned foam company. We visited Carpenter’s factory and have summarised our insights below.

Company Info

260 Carpenter staff operate out of the location in Manchester. The entire company has a turnover of $1.6 billion. They have their own chemical plant. Glossop is the number one foaming part.
Prison mattresses are about 2-3% of Carpenter's total UK income.
Carpenter has had the mattress contract with the MoJ for 20 years. For 9 years, the contract with Carpenter has been ‘zero waste’ with the potential of all the mattresses being recycled.

Production

The density of the base foam is 16 kg/m3, but the foam is 90kg/m3 post fire-seal treatment. This means the material has a high density but it is essentially a false reading as most of the density is the chemical.
There is only one Fireseal™ Machine.
The Fireseal™ mixture is aluminium trihydrate, latex, carbon black and water.
They did not have a figure for constant load pounding test, which is asked for in the contract.

Recycling

They have the ability to be able to recycle all the mattresses that they produce for HMPPS but this relies on getting the mattresses back from the prisons. They state their recycling rates through a KPI every year and they’ve reported as low as 45% and as high as 70%.
An interesting point to note is that Carpenter never receive any pillows for recycling from the prisons.
Carpenter processes 5 tonnes of foam everyday through the recycling plant, creating carpet underlay.

Insights

The recycling process at Carpenter is very effective and could achieve a 100% recycling rate. What needs to be improved is the waste management and training for the mattress end-of-life.
Making sure that pillows are also sent back to Carpenter would also stop a lot of waste from going to landfill and save money for HMPPS in their gate fees.
There is only one Fireseal™ machine producing the mattresses, meaning that if this machine were to be out of operation, the supply of mattresses would effectively stop immediately.
Carpenter are solely fixed on the fire-retardent of the mattresses and have paid less attention to the comfort, illustrated by the fact that, at the time of writing, they have not carried out the normal tests such as constant load pounding that is done on other mattresses.
The density of the mattress is made up mostly of the FR chemicals rather than base foam, explaining the speed of deterioration.

Custodial Mattress Requirements

There are several stringent requirements that the mattresses must meet in order to be used in the prison environment. When looking at the mattresses according to our design methodology, the four areas correspond with requirements for the mattress specification. Namely fire safety (feasibility), comfort of mattress over time (desirability), price over product lifetime (viability), and recyclability at end of life (sustainability).

Fire safety – Feasibility

In terms of fire safety, the inner and outer materials must be fire retardant to a Crib 7 standard. In addition, the mattresses are tested using the HMPPS FTS 15 ‘Igloo test’, which is a very difficult standard to achieve, resulting in very limited options.  

The prevailing cause of the mattress quality is the fact that the material has to be of the highest fire retardancy, so high in fact that the prison has their own classification and test that is four times more rigorous than the highest ‘British Standard’ rating. This means that the mattress foam is made up of mainly fire-retardant chemicals rather than being a supportive structure. This is a physiological approach to fighting and preventing fire, but it comes at the sacrifice of good quality sleep and potentially the physical and mental health of prisoners. However, if we also took a psychological approach to the mattress design, to increase the chances of good sleep and improve health, could this contribute to a decrease in reactive behaviour, or prevent the rate of fire-starting in the first place?

Mattress Comfort Over Time – Desirability

The mattresses in prison are multipurpose objects: they make up a bed for sleeping, a surface for sitting, eating, entertaining and everything else during your day. During our research sessions at HMP Standford Hill, the men reported 11 activities that were conducted on the bed: from sleeping and reading, to hanging clothes and cooking.  

"[The bed] is where you sleep, but the chairs (plastic chair) that they've got now, you don't really want to sit for any length of time so you sit on your bed." (Returned Citizen Interview)

Understandably, this multipurpose use means that there should be requirements for these mattresses to be extremely robust and withstand heavy use, which is stipulated in the MoJ Mattress Specification Document by the minimum product requirements. One of these requirements used to measure the robustness of a foam is the ‘constant load pounded test’ for foams used in furniture for public and private environments. To give an idea of the results below are the categories of the test results, (BS3379: 2005) with ‘extremely severe’ needing 240,000 rounds of compression to pass.

The MoJ asks for an ‘Extremely Severe’ (X) rated foam for the mattresses. However, when we asked the current mattress manufacturer Carpenter to provide these test results they said that they had not been carried out. In terms of comfort or desirability, the mattress requirements state that the product is ‘designed to provide reasonable comfort to prisoners throughout the product’s lifespan’ per the MoJ specification document: ‘The supply and recycling of mattresses and pillows’ (p.7). This is a vague requirement to meet as it does not have specific tests to adhere to. The contract also encourages innovation, stipulating that ‘within your bid you should detail the research and development you are willing to undertake to improve the product supplied.’

Research Approach for New Materials

iDax by ifoam Ltd

The first material goes by the trade name ‘iDax’ and is produced by ifoam Ltd. This foam is currently used for train seats as well as mattresses for sleeper trains, both which have extremely high fire and durability standards. The iDax material is produced in a completely different way compared to Carpenter’s foam and uses graphite-based fire retardant rather than Carpenter’s aluminium-based compound. iDax is a Flexible Polyurethane Graphite Impregnated Foam (GIF) which is cold cured in a mould with the fire retardant included. In comparison, Fireseal™ foam is impregnated after the foam is cured. The iDax production method means that the foam has more structural integrity as the fire retardant is a structural element of the foam itself.

iDax is a more expensive product due to the production method of moulding rather than block cutting, but there could be equivalent savings due to a longer lifespan. Director of ifoam Ltd, Garry McDonald, estimated that overall mattress costs would go down after 3 years once most of the old mattresses had been replaced with a longer lasting iDax mattress.

iDax Testing

iDax is specifically designed for bedding and seating and has an ‘extremely severe’ rating in the constant load pounding test, meaning it likely has a much longer lifespan than the current foam (it is very hard to compare this as there are no test results for Fireseal™).

During the project, we fire tested the foam at the fire and engineering department at the University of Central Lancashire. During these indicative tests, the foam passed the Crib 7 test but failed the FTS15 ‘igloo’ test. This was the first time the foam had been tested without a fire blanket (other BS standards do not require foam to be tested as an independent product) and it indicated ways the foam could be improved. As result, the iDax foam tested could be used for upholstery and for pillows but not for mattresses in its current state.

In terms of recycling, the foam could potentially be broken down into ‘sticks’ of foam that could then be used to create pillows, which could then be ground down and added into the foam mixture at 15%, meaning there would be no material wasted in the process.

Envirolay by Texfelt

Envirolay is sold as a carpet underlay but it is commonly used as a layer in sprung mattresses. It has a very good fire rating, although it has not been tested to bedding standards, as it is categorised as flooring.

The interesting angle of this material is that there is the possibility to use waste from the prison industries textiles workshops. A huge amount of textiles end in the prison waste stream from prison textile workshops which produce large quantities of scrap fabric from cutting as well as clothes and textiles from the prison cells. This material could be utilised to make Envirolay, which is produced by needle felting and creates a very dense material which is what gives it its fire retardancy. Enabling this system would mean that the waste textiles would be utilised rather than sent to landfill, and the prison would get a material that is fire retardant without the addition of damaging chemicals, due to the mechanical method of production.

This material is designed to lay under flooring so it can withstand heavy usage. The use of a layer such as Envirolay in a mattress or seating prolongs the life and increases comfort whereby a combination of hard and soft layers provides more support while lying down or sitting, and the harder layer supports the softer layer reducing the rate of wear and tear.

This proposal would be a long-term project, but the amount of textile waste created by HMPPS should be addressed. If this material can be utilised by the prisons themselves then all the better. This is an area to legitimately consider if HMPPS wants to move into a circular economy system.

Proposals & Actions

Immediate

At the time of writing, the MoJ has two years left on the Carpenter’s contact, so we would recommend an immediate action of talking to Carpenter to ask for steps to be taken to improve their product. There is a sole fixation on the fire retardancy of the mattresses and not the comfort, because that it what it says in the specification. A change in future contracts to put more emphasis on comfort may change the way the mattresses are produced. Priority should be placed in extending the lifespan and comfort. Actionable objectives to help achieve this would be performing a constant load pounding test and highlighting the need for innovation within the contract.

In the short term, since iDax has passed Crib 7, it is able to be used for pillows and upholstery. PSPI Sector Lead, David Bray, has visited the ifoam Ltd factory and is recommending them for the contract bid for the upcoming upholstery contract that will be accompanying the opening of a new prison industries workshop. This route may work in a more practical way, as ifoam Ltd would be able to develop a relationship with HMPPS and develop the fire resistance of iDax to the level of custodial mattresses alongside this potential contract.

We have also put into action a relationship between MoJ National health, Safety and Fire Lead, Mark Simpson, ifoam Ltd and UCLAN who plan to continue testing the iDax foam once changes are made to increase the fire-retardant standard.

Future

As a longer term and sustainable solution, we would propose a new project around mattresses, specifically working with iDax to develop their foam and create mattresses, which could then be used for a prison wide trail monitoring sleep, health, aggression and the life span of mattresses. Below is a proposed draft of what this project could look like.

Mattress Project Proposal