Laboratory Tests

Laboratory Tests

What can we test at our laboratory?

What can we test at our laboratory?

Our Technology Centre is where we return to the roots of why we do health and safety. The newly built suite brimming with cutting-edge test equipment is where we put our products through their paces.

The centre is split into three separate laboratories:

  • Chemical Laboratory: For testing permeations, EN 374:2016 chemical tests, and both infra-red and ultra-violet spectrometry for material absorption and emission (FTIR and UV-Vis), overall migrations, colour fastness.
  • Physical Laboratory: For abrasion resistance, blade-cut resistance, tear resistance, puncture resistance, tensile strength, dart impact, force at break, elongation 
  • Wet Laboratory: For water leak and washing tests.

Why have our own labs?

Our Technology Centre is (soon to be) UKAS-accredited and enables us to carry out our own testing for CE certification and compliance. This means for the vast majority of tests, we’re not dependent on a third party and we save time and money.

All PPE products require varying degrees of testing. These tests prove the products comply with their standards and allows us to add a CE mark to them. We also use the labs to test new product developments and help resolve customer complaints.

We also offer guided tours of the facility which customers really value. For example, by learning about standards tests during the Assessing Hand Protection Course and then seeing it in action, our customers can receive an enriched learning experience.

EN374-2 Determination of Resistance to Penetration

This is the reference test specified by the European Standard for the assessment of glove quality. Gloves must pass this test in order to prove that they are an effective barrier against liquids and micro-organisms. A statistical sample taken from a batch of gloves is subject to checks for pinholes and leaks by inflation with air and by filling with water. Performance levels are assessed according to the acceptance quality limit (AQL) of the gloves. Gloves must meet at least level 2 of EN374-2 to be considered micro-organism resistant.

AQL tests

EN374-2 Determination of Resistance to Penetration

EN374-3 Determination of Resistance to Permeation by Chemicals has changed to BS EN 16523-1 for Breakthrough Time

Resistance to permeation is assessed by measuring the time for a quantified amount of a chemical to permeate through the glove material as shown below:

EN374 3 permeation time

Samples taken from the palm of gloves are placed in a permeation cell which enables the outer surface of the glove to come into contact with the challenge chemical. Collection air or water is passed through the cell to collect any chemical that has broken through to the inside surface of the glove sample. Polyco Healthline laboratories are equipped with conductivity electrodes to detect acids and alkalis and a GC to detect polar solvents.

Six extra challenge chemicals have been added to the revised standard EN374-1: 2016 (added chemicals shown in bold) increasing the number from 12 to 18.

A- METHANOL

B – ACETONE

C – ACETONITRILE

D – DICHLOROMETHANE

E – CARBON DISULPHIDE

F - TOLUENE

G - DIETHYLAMINE

H - TETRAHYDROFURAN

I -  ETHYL ACETATE

J – n-HEPTANE

K – SODIUM HYDROXIDE 40%

L – SULPHURIC ACID 96%

M – NITRIC ACID 65%

N – ACETIC ACID 99%

O – AMMONIUM HYDROXIDE

P – HYDROGEN PEROXIDE 30%

S – HYDROFLUORIC ACID 40%

T – FORMALDEHYDE 37%

The pictograms will also be changing with chemical protective gloves now classified into three types dependent upon their performance:

  • Type A – tested against 6 chemicals with each meeting a minimum permeation level of 2 (chemicals code detailed below)

374 type a

  • Type B – tested against 3 chemicals with each meeting a minimum permeation level of 2 (chemicals code detailed below)

374 type b

  • Type C – tested to 1 chemical and passed minimum level 1 (chemicals code not shown)

374 type c

As part of EN374-1: 2016 a new mandatory requirement for any chemicals claimed on the product marking is EN374-4:2013. This procedure looks at the degradation resistance of the glove material to dangerous chemicals.

The glove material is tested for puncture resistance before and after continuous exposure to the challenge chemical and any observations made regarding change in the physical appearance such as swelling, hardening, disintegration are also reported.

There is no minimum requirement for degradation but the results must be reported in the user information.

EN388 Protective Gloves Against Mechanical Risks

The following equipment is used to assess the properties of gloves specified by the EN388 standard.

A Martindale wear and abrasion tester is used to measure the abrasion resistance.

The test involves rubbing samples, cut from the palms of gloves, against a standard glass paper until a hole is worn through one of the samples. The number of abrasion cycles is used to assess the performance.

A Coup cut tester is used to measure the resistance to cutting.

Samples are cut from gloves and placed in a frame which enables a circular, counter-rotating blade to slice through the glove material. The number of cycles required by the blade to cut through the glove are recorded. These are converted into a cutting index by comparison with the number of cycles required to cut through a standard reference material. The standard now allows for an alternative test method to be used for highly cut resistant products and this test is described in EN ISO 13997. It measures the force required to make a cut in the test sample 20mm long and is often referred to as the ISO Cut Test. Performance levels are established according to cutting index.

Puncture and tear resistance are measured with a tensometer. Puncture resistance is measured as the force required to break through samples from gloves with a standard puncture needle (it should be noted that the design of this needle is comparable to that of a large nail, and the puncture strength from this test cannot be used to assess resistance to puncture by hypodermic needles).

Tear resistance is measured as the force required to tear apart samples from the glove, which are in the form of a pair of trousers (this test is also known as a trouser tear test). The legs of the trouser samples are pulled apart and the maximum force used to assess tearing resistance of the material.

EN388 tests

EN388 Protective Gloves Against Mechanical Risks

EN420 General Requirements for Gloves

This standard includes tests for glove dimensions, dexterity and allergens. For example, leather gloves are required to have a chromium VI content less than the limit of detection (3 ppm). Gloves are tested for innocuousness to ensure safety for the user.

EN407 Protective Gloves Against Thermal Risks

Burning Behaviour is tested according to EN ISO 6941 with the glove mounted and tested vertically. A flame is placed directly below and in line with the glove at an angle of 30° and a distance of 20mm. The glove is tested for each ignition time i.e. 3 seconds and 15 seconds.

heat test 2

The flame time and after glow time for each performance level is as follows:

Contact Heat is tested according to EN702. Samples are taken from the palm area and placed in contact with a cylinder of the appropriate temperature. To gain the relevant performance level, the temperature of the inside of the glove cannot rise by more than 10°C within the threshold time.

heat test 3

Convective Heat is tested according to EN367 : 1992. Samples are subjected to the incident heat from a flame, and the heat passing through to the inside of the glove is measured. The time to record a temperature rise of 24°C is the Heat Transfer Index (HTI).

 heat test 6

Radiant Heat is tested according to EN ISO 6942 : 2002. The sample is exposed to radiant heat density of 20kW/m2 and the time taken for the temperature on the inside of the glove to rise 24°C gives the performance level.

heat test 7

Resistance to small splashes of molten metal is tested according to EN348 : 1992. Molten drops from a metal rod melted by exposing the rod to a flame are allowed to fall on the sample. The number of drops required to raise the temperature on the inside of the glove by 40°C gives the performance level.

heat test 8

Resistance to large splashes of molten metal is tested according to EN373 : 1993. A quantity of molten iron is poured onto the sample, which has a PVC film mounted behind the sample. This film must not show any changes to the surface (such as discrete spots or damage) when the sample is exposed to the quantity of molten iron as shown in the table opposite.

heat test 9

EN511 Protective Gloves Against Cold

Convective Cold is tested by measuring the power required to maintain a constant temperature on a heated full-scale hand model in the ambient atmosphere of a climatic room which provides uniform conditions. The hand model is typically heated to 30-35°C. The resultant thermal insulation (ITR) is calculated using the hand model temperature, climatic room temperature and the power consumption of the heated hand to maintain a constant temperature.

cold test 1

Contact Cold is tested according to ISO 5085-1 : 1989. The Thermal Resistance (R) is calculated by placing the sample on top of a heated plate with another metal plate (cold plate) placed on top of the sample. This is placed inside a cabinet which has an extractor fan to draw air past the assembly which has a cooling effect on the cold plate. The temperature gradient either side of the sample is measured and compared with the temperature gradient either side of a reference standard. The Thermal Insulation is calculated from the known thermal resistance of the standard and the measured temperature gradients.

cold test 2

Water Impermeability is tested in accordance with EN ISO 15383. Water penetration shall not appear less than 30 minutes after the start of the test and is essentially a pass or fail.

EN60903 Live Working Gloves of Insulating Material

To obtain compliance with EN60903, all gloves must be tested to the relevant voltage in the table opposite. The construction, thickness and test voltage combine to give the class compliance. To maintain compliance, gloves of classes 1, 2, 3 and 4 must be inspected every 6 months.

insulation test 1