This work demonstrates that when a polyurethane coating is swollen by the presence of cleaning agents it is more prone to damage. This suggests increased exposure to cleaning agents may lead to an increase in the risk of mattress failure.

Jo Milnes MA(Hons), MSc(Dist): Technical Manager, Dartex Coatings Limited, Acton Close, Long Eaton, Nottingham, NG10 1FZEmail: jo.milnes@dartexcoatings.com

BACKGROUND

The Impact of Cleaning Chemicals on Polyurethane Mattress Cover Materials and their Propensity for Physical Damage

MDA/2010/002“Mattress covers can become damaged at any time during use or storage for example from: needle stick, strikethrough, damage from sharp object; abrasion during handling, transport or movement, inappropriate cleaning and decontamination procedures”.

Previously, many studies have examined these issues in isolation. This preliminary study investigates the relationship between the cleaning and decontamination methods and the increased vulnerability to physical damage of polyurethane coatings.

SUMMARY OF RESULTS

CONCLUSION

The recent MHRA Device Alert (MDA/2010/002) highlights concerns in the medical care industry over possible infection risks to patients caused by damaged mattress covers that are no longer an e�ective barrier to �uid ingress. The alert lists possible causes of damage as:

REFERENCES1. MHRA Poster - © Crown copyright Jan 2010 - http://www.mhra.gov.uk/home/groups/dts-pcc/documents/publication/con065724.pdf - Accessed on 26 March 20122. Discovering Polyurethanes, Konrad Uhlig, Hanser Publishers, Munich ISBN: 1-56990-272-03. ECVV - http://upload.ecvv.com/upload/Product/20117/China_Crock_Meter_Manual 20117221613216.jpg4. NaDCC was kindly supplied by Ecolab - http://www.ecolab.com5. Protect, Rinse Dry. BHTA Guidance on care, cleaning and inspection of healthcare mattresses. http://bhta.net/resources/site1/general/Reports/51464%20Protect,rinse,dry.pdf

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Dartex Coatings Limited - Acton Close - Long Eaton - Nottingham - NG10 1FZwww.dartexcoatings.com +44 (0)115 9837676

Dartex Coatings provides solutions for the healthcare market. Our products are key to the mattress performance, enhancing anti-decubitus, durability, chemical resistance, anti-microbial and moisture vapour permeability properties. Dartex Coatings works to aid healthcare professionals in their everyday working environment.

In order to maximise the life of your mattress cover we strongly recommend that you follow the ‘Protect, Rinse, Dry’ Procedure outlined by the BHTA Guidance on care, cleaning and inspection of healthcare mattresses .

The chemical resistance of polymer coatings used today for mattress covers varies considerably. It is therefore critical to consider this attribute in line with other key performance requirements such as breathability, stretch, �ame retardance, anti-microbial etc., when specifying your mattress cover requirements.

The test fabric was wiped 10 times on the polyurethane face and then whilst it was still visibly wet and swollen a reproducible abrasion force was applied 10 times across the surface using a crockmeter as outlined in ISO 105-X16:2001 and shown below in Figure 1 below:

Following abrasion testing, waterproof performance of the fabric was then assessed using BS3424:1990 Part 26; method 29C (resistance to water penetration).

Test Method 1

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[5]

This investigation was to study the cause of the high mattress failure rates, it is not aimed to validate any particular cleaning or decontamination routine, but to look at its impact.

All of the chemicals assessed are currently used in hospitals for cleaning and disinfection purposes. A range of di�erent mattress cover materials were selected for assessment as the polymer type would be expected to have an impact upon cover performance. All of the cover materials examined have a transfer coated polyurethane coating on a synthetic textile substrate. Polyurethanes (PUs) comprise a vast group of polymers with literally thousands of di�erent types commercially available, o�ering a wide range of performance including various levels of moisture vapour permeability, chemical resistance and hardness (higher modulus).

[2]

Rationale

This study includes four di�erent coating systems manufactured by Dartex in addition to another readily available alternative, each has a di�erent level of moisture vapour permeability (MVP), chemical resistance and hardness. One of the products tested is the “standard” Dartex material that has been used by the NHS for the past 30 years.

Note: Whilst manufacturers of the cleaning and disinfection agents do not recommend that their products are used in this way, this test seeks to illustrate the impact of such use and the relative performance of each coated product group.

All product types were then exposed to continuous wet surface contact with 10,000ppm NaDCC and assessed at regular intervals by using BS3424:1990 Part 26; method 29C (resistance to water penetration).

Where loss of waterproof performance occurred, results were recorded to the nearest 24 hour period.

Test Method 2

[4]

Dartex Standard Coating

Dartex Higher Modulus Coating

Dartex Chemically Resistant Coating

Dartex High MVP Coating(Moisture Vapour Permeability)

*

**

***70% IPA

1,000ppm Hypocholrite

10,000ppm Hypocholrite

1,000ppm NaDCC + Detergent

Key

No Stars

Wat

er P

enet

rati

on R

esis

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e

******

H/H- No Change

- Some Loss but Greater than Speci�cation

- Less than Speci�cation

Reduction in Waterproof Properties with Wet Abrasion

Other

3 Days

7 Days

16+ Days

Extreme Testing of 10,000 PPM NaDCC Continuous Wet Contact

Other

Other Alternative Coating

The Dartex Higher Modulus and Chemically Resistant Polymers signi�cantly outperformed the Dartex Standard Coating

The Alternative Coating and Dartex Higher MVP Coating both lost hydrostatic head in less than 4 days resulting in loss of water penetration resistance which potentially could lead to a cross infection risk.

Comments to Figure 2

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All the above coating systems were inspected for damage after testing:

Swelling in the coating was observed and a change in the coating surface appearance was noted on the standard polymer after IPA testing. This did not lead to a loss in hydrostatic head.

The higher MVP coating swelled considerably, contributing to the failure during abrasion.

Comments to Figure 1

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Figure 1: Figure 2:

3. ECVV - http://upload.ecvv.com/upload/Product/20117/China_Crock_Meter_Manual20117221613216.jpg

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The investigation into the cause of failure for damaged covers tends to be performed once covers are dry and often after decontamination, this does not necessarily represent the state of the cover at the point of failure. Over 85% of such covers examined by Dartex Coatings have been found to have some form of physical damage, but to date there has been little research into the performance of polyurethane coatings during and immediately after cleaning.

Further research is planned to identify a clearer distinction in performance between the available polymer systems, cleaning reagents and appropriate test methods.