Tuesday 22 June 2010

Safety Gloves for Mechanical and other Hazards

In a previous article we gave details of Safety Gloves for protecting against the risk of handling chemical and biological hazards, now we will give information on other types of safety gloves to protect against other hazards.

Safety Gloves should be issued and worn after undertaking a Risk Assessment for people who have to handle or come into contact with:
  • Materials with sharp or rough edges
  • Very hot or very cold materials
  • Fire
  • Electrical current
There are certain standards that have to be conformed to:
  • EN 388 is for gloves designed to provide protection against mechanical risks. It specifies requirements for resistance to damage from abrasion, perforation, tearing and cutting.
  • EN 407 is for gloves designed to provide protection against thermal hazards e.g. heat and or fire.
  • EN 511 is for gloves designed to protect from cold conditions.
  • EN 12477 is for gloves designed to give protection when using welding equipment.
Gloves for protection against mechanical hazards usually have a fabric base to provide resistance to damage. For years the outer fabric was leather but now the outer is made from a polymer that gives protection from water and chemicals. For resistance to cuts the outer is often made of synthetic high performance yarns e.g. Kevlar™. Generally these gloves are re-usable rather than disposable. However if the outer surface has been damaged they must be disposed of immediately, regular checks must therefore be made.

The types of materials most commonly in use are:
  • Latex natural rubber is a very elastic and flexible material depending on the formulation of a particular glove, natural rubber can offer abrasion, tear and cut resistance. However some people suffer allergic reactions to latex, so individual user requirements must be taken into account.
  • Nitrile gives excellent abrasion and puncture resistance whilst retaining flexibility and comfort. It is also less likely to cause allergic reactions.
  • Polyvinyl Chloride PVC can offer abrasion and puncture resistance, if thick enough it can afford some cut protection. Generally tear resistance is poor.
  • Leather a natural material can be modified during the tanning process to give different properties. Leather gloves come in a large range of thickness and styles and vary widely in protection given, from specialised to very basic general purpose gloves.
  • Kevlar™ brand fibre (Par Aramid fibre) a specialist artificial yarn from which gloves and sleeves can be knitted. These have excellent tear, abrasion and cut resistance.
For gloves tested against EN388 there should be a pictogram with numbers underneath to show the level of protection against from left to right; abrasion, cut, tear and puncture. The levels go between 0 and 4 for abrasion, tear and puncture and 0 and 5 for blade cut resistance. 0 means it has either not been tested or has failed.

4 2 3 1

There is also a pictogram for gloves that have a particular resistance to impact cuts

At no time should protective gloves be used as an alternative to the fitting and proper use of guards on machinery or tools.

Thermal Hazards

Gloves that are resistant to thermal hazards either heat or cold can be manufactured using a variety of materials.
  • Aluminised gloves help with the reflection of heat and are normally used where the main source of heat is radiant e.g. in a blast furnace. Materials often aluminised are Para Amid and leather.
  • Leather is a good protective material against cold as long as it does not get wet and often they are treated with waterproofing agents. Leather is also a good material for welding gloves as it does not melt or burn unlike many synthetic fibres.
  • Poly Viloft is a synthetic fibre that gives good thermal insulation properties against cold.
  • Para Aramid e.g. Kevlar™ developed for aerospace to give heat resistance for the extreme temperatures during re-entry into the Earth’s atmosphere, is extremely good against flame, and convection heat.
  • Cotton has only moderate resistance to heat and cold, the main problem is that to be effective the material has to be thick which limits dexterity.
In the standards for resistance to cold the following categories are used:
a. Resistance to convective cold 0 to 4
b. Resistance to contact cold 0 to 4
c. Permeability to water 0 to 1

The Pictogram used to show that gloves are resistant to cold is

3 2 1

In the standards for resistance to heat the following categories are used:
a. Resistance to flammability 0 to 4
b. Resistance to contact heat 0 to 4
c. Resistance to convection heat 0 to 3
d. Resistance to radiant heat 0 to 4
e. Resistance to small pieces of molten metal 0 to 4
f. Resistance to large splashes of molten metal

The pictogram used to show the gloves resistance to heat is

4 3 2 3 2 1

There also standards applicable particularly to chainsaw protective gloves that have been covered in previous articles on the Granite Workwear web site see A Guide to Chainsaw Protective Clothing and Equipment published 11th June 2010.

In our range of gloves we have products that cover all aspects of protection.

Thursday 17 June 2010

Safety Gloves for Chemical and Biological Hazards

Safety Gloves should be issued and worn after undertaking a Risk Assessment for people who have to handle:
  • Hazardous materials
  • Toxic chemicals
  • Corrosive materials
No single glove will meet the needs of everyone. Gloves must be selected on the basis of the materials being handled and the type of work undertaken.

The use of protective gloves should be seen as a control measure of last resort and should always be used in conjunction with other measures. This is because:
  • Gloves only protect the wearer – they do not remove the contaminant from the workplace environment.
  • If protective gloves are used incorrectly, or badly maintained, the wearer may not be protected - when gloves fail they fail completely which then exposes the user to the hazard.
  • Gloves themselves can cause skin problems.
  • Wearing gloves interferes with the wearer’s sense of touch.
  • The extent of protection depends on good fit.
  • Some types of glove are inconvenient and interfere with the way people work.
However, by selecting the right glove for the task at hand, understanding the limits of the selected glove and by knowing how to correctly use them, gloves can help to remove dangerous exposures.

There are various standards that have to be achieved for different risks.

EN 374 is for gloves designed to protect from chemicals and micro-organisms. This standard specifies the requirements of gloves for protection against chemicals and/or micro-organisms. Specific Requirements are that gloves need to be:
  • Sealed against penetration of liquids according to method in EN 374-2. This test is a pass/fail test.
  • Permeation resistance to chemicals tested according to method EN 374-3. Each combination of glove/chemical is classified according to the time the glove resists to permeation of the chemical.
EN 455 is used to assess gloves intended for use in health care. A glove that conforms to this standard will provide adequate protection against infection risks, but chemical resistance will not have been assessed.

There are four factors to consider when deciding which glove is suitable for your work

(a) The type of hazard (chemical type, Bio-hazard)
(b) The task
(c) The user (size and fit, state of health, etc.)
(d) The workplace conditions (ergonomics, temperature, wet or dry, etc.),

They need to be considered together and not in isolation as it is the interaction of all these points that will determine the suitability of the glove.

In the Risk Assessment it is not enough to simply state that gloves are required, the type of glove must be specified along with any other control methods used to avoid or limit contact and also any special measures that must be taken to ensure that the protection of the glove is maintained, for example specifying when gloves should be changed.

Chemical Hazard

It is impossible for one glove material to offer complete protection from all substances/chemicals. All of them are liable to damage or failure by degradation or permeation by some chemicals. In most instances where there is need for protection against accidental contact, a nitrile glove will be the best choice.

Degradation is damage caused by changes in one or more of the physical properties after contact with the chemical, signs of degradation are normally visible with indications being swelling, loss of flexibility or areas of stickiness.

Permeation is where a chemical passes through the glove material by diffusion without damaging the actual glove, this is normally expressed as the ‘breakthrough time’, this is the measure of how quickly a chemical can permeate the glove and will be specific for the particular model of the glove.

Generally the thicker the glove, the longer the breakthrough time is. The breakthrough time is the maximum time that it can be used in contact with the hazard and must be changed at that time even if the task has not been completed. Breakthrough time can also be impacted adversely if the chemicals are warmer then the ambient temperature and also are of higher concentration.

If the task involves working with chemicals classed as toxic, harmful on skin contact or capable of absorption through the skin you should always consult the material safety data sheets for the chemicals used, or a chemical resistance chart to select the most suitable type of glove.

Examples of Chemical Hazards










AreaExample of Hazard
EngineeringMetalworking fluids, oils, solvents, degreasers, adhesives, cement, etc.
LaboratoryAcids, alkalis, oils, solvents, etc.
MaintenanceSolvents, oils, paint, epoxy resins, degreasers, cements, tar, etc.
PrintingProcessing chemicals, inks, plate cleaning solvents, adhesives, etc.
CateringDishwasher liquids, oven cleaners, surface cleaning agents, water, etc.
AgriculturePesticides, weed-killers, oils, solvents, etc.
CleaningBleaches, cleaning agents, detergents, water, etc.
JanitorialCleaning agents, solvents (i.e. bleach), etc.
OfficeSolvents, glues, cleaning agents, water, etc.


Whereas the thicker the material generally the more resistance the need for dexterity has to be taken into account in the selection of the glove. Also the cuff length must be taken into account; generally disposable gloves cover only a small area of the wrist, often leaving a gap between the glove and the sleeve of the protective clothing. There are longer gloves available to eliminate this.

Grip requirements also need to be taken into account, if working in wet and oily conditions gloves with a textured surface should be used.

Abrasion, puncture, tearing and snagging risks also have to be taken into account, generally disposable gloves do not offer good resistance to these hazards and therefore thicker re-usable gloves should be considered.

User requirements

Using the correct size of gloves is essential; gloves that are too small will restrict the hand and cause fatigue and rashes. Gloves that are too large are also uncomfortable, interfere with grip and can easily get snagged, a full range of sizes should be available.

Many people are allergic to latex and exposure can cause rashes, breathing problems and in very rare cases anaphylactic shock. In this case then nitrile gloves should be used.

Any cuts and abrasions on the hands should be covered with a waterproof dressing before donning the gloves.

If somebody has eczema they may need to use a cotton liner inside the gloves. Also they should use a moisturising cream after washing their hands after using the gloves.

Granite Workwear have a comprehensive range of safety gloves suitable for all uses on our website.

In a later article we will be looking at Safety Gloves for Mechanical and Other hazards.

Friday 11 June 2010

A Guide to Chainsaw Protective Clothing and Equipment

Chainsaws are potentially one of the most dangerous tools in general use, the saw is made to cut easily through large branches and tree trunks so any part of the human body will have no resistance at all to the cutting power in use.

Therefore there are recognised standards for the PPE required to minimise the risks in the case of clothing these are the standards EN 381. These standards specify levels of protection related to the speed of the chain and also the amount of coverage of the protected areas.

Class 0 resists chains up to the speed of 16 metres per second
Class 1 resists chains up to the speed of 20 metres per second
Class 2 resists chains up to the speed of 24 metres per second
Class 3 resists chains up to the speed of 28 metres per second
Class 4 resists chains up to the speed of 34 metres per second

There are also different parts to the standards each of which covers a specific part of the body:

EN 381-5 Leg protection
This is split into 3 different levels A, B and C and the minimum requirement is Class 1
A protects the front and ride side rear to both legs
B gives additional protection to rear left side of the right leg
C gives all round protection to both legs

EN 381-7 Chainsaw Gloves
This is split into 2 Different Levels A and B
A gives protection to the left hand
B gives protection to both hands

EN 381-9 Chainsaw protective Gaiters
These are recommended for occasional chainsaw users when working on even ground with little risk of tripping or snagging, worn in combination with steel toecap safety boots

EN381-11 Upper part of Body
These garments are normally Class 0 as to achieve higher levels would involve so many layers of material that the garment will be too heavy and unwieldy, leading to lack of mobility and the increased risk of heat exhaustion, both of these will have a negative impact on Safety.

There is a separate standard for Footwear EN 17249:2004
These items cannot be Class 0, they can be Class 1, Class 2 or Class 3 and are the only items that can achieve Class 4 status.
They must be marked with the Year and Quarter of manufacture.

How does chainsaw protection work?

There is no flexible material that can be worn as clothing, gloves or boots that can be totally impervious to cuts from chainsaw blades. Therefore a number of layers of protection are the only way forward.

The outer layer normally comprises of a material that is tough and slippery, this is mainly to ensure that outer surface is resistant to minor damage from thorns and other snagging mediums, which could expose the under protective layers. Beneath this, long, loose fibres of ballistic nylon or Kevlar are layered. When a saw contacts the trousers, the outer layer is immediately cut and the nylon or Kevlar is drawn out and wraps around the saw's drive sprocket, locking it solid and halting the chain, thereby limiting damage to the operator's limb.

Once the item has been cut it must be scrapped as the protection has been totally compromised. The saw must be stripped down and the fibres fully removed before using it again.

Marking

All Chainsaw protective clothing, boots and gloves sold in the EU must carry a pictogram depicting a chainsaw and information of the Class and Design it is rated to, this pictogram must be a minimum of 30mm x 30mm. For example:

Other items that must be used when using a chainsaw are:
Safety Helmet to the minimum standard EN 397 but recommended to EN 12492 if involved in tree climbing operations.
Hearing Protection to EN 352-1 (noise levels are typically 115 dB)
Eye Protection Mesh Visor to EN 1731
Safety Glasses to EN 166
As these are used for protection in other activities not just for chainsaw work they do not have to be marked with the pictogram.

Granite Workwear has always kept up to date with the latest developments in Chainsaw Protective Clothing and Equipment and indeed have a specialist Forestry section on the web site which is subdivided into Clothing, Footwear and Tools and Accessories. New items are added on a regular basis as they become available, we are very happy to answer any questions you may have on what is the best solution for your particular needs.