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.

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