CHOOSING THE RIGHT GLOVE
by Sheryl Hoffmann BSc, Grad Dip Occ Health
c/o Concrodia College
45 Cheltenham St
Highgate 5062
Phone: 8272 0444
Email: shoffmann@concordiua.sa.edu.au
© Sheryl Hoffmann, 2010
1.
INTRODUCTION
Choosing the right glove for the school Science laboratory area is a complicated job
due to the variety in the task performed. No one glove will be suitable for all tasks so
a decision must be made on what glove is the most appropriate for each task. The
decision will be based on the hazards of the tasks, both physical and chemical, and
the style and characteristics of gloves available for purchase.
First all hazards that may impact on hands is listed, followed by problems with
wearing gloves, then all the factors that need to be considered when deciding on
which glove to wear. Next, terms like penetration, permeation and breakthrough time
are explained to help understand the physical characteristics of gloves materials
when in contact with chemicals. This understanding is needed to understand issues
of wearing, cleaning and disposal of gloves and when alternatives are a better option.
The paper finishes with a discussion on how gloves are characterized and labeled, to
assist in purchasing.
This paper looks focuses on the Science area but the principles can be used in any
area.
2.
WHY DO WE WEAR GLOVES?
Gloves are worn to protect the hands against a wide range of hazards.
Including:

Mechanical hazards

Cuts

Punctures including needles and broken glass

Friction / Abrasion

Thermal

Contact with extreme cold

Contact with extreme heat

Flame

Radiant heat

Molten metals

Biological

Microgiological Organisms

Enzymes

Irritatant plants

Sensitisers

Vibration

Electric Shock

Radiation

Chemicals

Corrosive eg acids

Toxic eg pesticides, laboratory chemicals

Provoke allergic reactions / sensitisers eg latex

Prolonged contact with water

Contact with dirt, oil and grease
3.
WHEN SHOULD GLOVES BE WORN?
Protective gloves should be worn when a risk assessment of the task to be
performed, has identify hazards that can be minimised by the wearing of gloves.
The wearing of gloves is the least desirable alternative when selecting a control
measure using the Hierarchy of Controls. Often they are worn if other more preferred
measures do not sufficiently minimise the risks.
4.
PROBLEMS WITH GLOVES
Gloves can cause problems which should be addressed or they may reduce the
likeihood of gloves being worn when they should be. These problems including:

Reduced dexterity

Reduced tactile sensation

Accumulation of sweat under the glove

Allergic reactions

Time to put on and take off

Poor fit or comfort

Cost

Maintenance and cleaning

Inconvienent

Interfer with the work

Workplace conditions – heat, wet work, repetitive movement
5.
WHAT NEEDS TO BE CONSIDERED WHEN SELECTING GLOVES?
5.1 Hazards to be protected against
The main issue in selecting a glove is the hazards encountered while
performing the task. The risk assessment is a vital process to help identify all
the hazards likely to be encountered.
5.2 Size
The sizing of gloves can be found in the following table:
Glove sizes
Symbol
Size
XS
7 inches
S
7 - 8 inches
M
8 - 9 inches
L
9 - 10 inches
XL
10 inches
The size of the hand is taken 20mm above the outstretched thumb, across the
knuckles, as indicated in the diagramm below. The measure in inches gives the
standard size of the glove. The length of the hand is also standardised.
5.3 Comfort and fit
Comfort and fit are important. An ill fitted or uncomfortabel glove is less likely to
be worn.
5.4 Glove construction
Gloves may be supported or unsupported. Supported gloves have a cotton
backing that gives extra thickness and stability to the glove. This reduced the
dexterity somewhat but is generally able to withstand a higher level of abrasion
and chemical attack.
Some gloves have seams but many people prefer the knitted style of gloves
that do not have seams. (pictured below) This type of glove is often a knitted
glove that has the palm and finger areas dipped in a protective coating such as
latex. This partical covering also allow the hand to breathe more easily. The
protective coating may also be textured to provide extra grip for wet or oily
situations.
Gauntlet style gloves provide protection to the forearms as well as the hands.
This may be useful when taking hot items out of an oven or to prevent liquids
slopping over the top of gloves for example when washing glassware.
5.5 Liners
Separate liners may also be worn under gloves. Cotton liners absorb sweat and
increase the thermal properties of the glove. Other liners may increase the level
of protection from cuts and abrasions.
5.5 Disposable or reusable
Disposable gloves are thin. This allows good dexterity and tactile sensation but
they have little chemical or abrasion resistants. They are designed for incidental
chemical contact such as splashes or spills, not intentional contact such as
immersion. They are designed for single use only and should never be reused.
They should be replaced regularly. They should also be replaced immediately if
they come in contact with chemicals, including incidental contact such as
splashes or spills. They are not suitable for aggressive or highly hazardous
chemicals. They are also not suitable for for tasks with significant mechanical
stresses, as they easily tear or puncture.
Disposable gloves may be powered, low powder or not powdered. Powder
assists the wear to put on and take off the glove. Powered latex gloves can
increase the liklihood of developing a latex allergy.
Reusable Gloves are generally thicker with a lower level of dexterity, but they
have greater protection against abrasion, are less likely to tear and will resist
chemical attack for longer. They require cleaning and inspection before reuse.
5.6 Level of Dexterity
For many tasks in the Science laboratory a high level of dexterity and tactile
sensation is required.
5.7 Ensure That No Additional Hazards Are Introduced
It is important to perform a risk assessment on wearing gloves while performing
the task. Additional hazards may be introduced. If this is the case an alternative
to gloves or a difference type of glove might need to be considered.
In all case it is important that the employee who is doing the task and wearing
the glove is consulted. They must be acceptable to the wearer or they are
unlikely to wear them. Cultural differences may also influence the type of glove,
for example cultural differecnce may rule out the use of pigskin.
5.8 Risks From Chemical Exposure
Chemical exposure may cause skin damage or the chemical may be absorbed
through the skin and cause internal effects.
In addition contact with liquid chemicals or solvents may dry the skin causing it
to crack, as will prolonged contact with water or excessive or improper skin
cleaning.
6.0 UNDERSTANDING THE PHYSICAL CHARACTERISTICS OF GLOVES MATERIAL
WHEN IN CONTACT WITH CHEMICALS
Gloves are not the impervious barrier that most people think they are. Any chemical
will eventually get through any glove. There are three factors that affect the physical
characteristics of glove material: degradation, permeation and breakthrough time.
Each must be understood so that the correct glove material is selected for a given
chemical and application.
6.1 A glove may be degraded by a chemical. In this case the chemical changes the
physical and/or chemical properties of the glove. This is often (but not always)
visible to the naked eye. eg latex gloves will disintegrate in acetone. Signs of
degradation include swelling, loss of flexibility and tackiness
6.2 A glove may have seams, pinholes or other imperfections in which a chemical
or microorganism may pass through. This is called penetration.
PENETRATION
Outside
(chemical)
Inside
(hand)
Pinhole, seam or other imperfection
Glove
6.3 A chemical will also diffuse through the glove material on a molecular level from
the outside to the inside. This process is called permeation. Permeation occurs
through an intact glove without damaging the glove material.
PERMEATION
Outside
(chemical)
Inside
(hand)
Glove
There are two factors to consider when looking at permeation of a chemical
through a glove.
1.
Permeation rate - the rate at which a substance permeates the glove
material.
2.
Breakthrough time - the time elapsed between initial contact of a
chemical with the outside surface of the glove material and the time
at which the chemical can be detected at the inside surface of the
material.
Once breakthrough has occurred the chemical will be in contact with the skin
and may cause damage to the skin. Depending on the chemical it may also
permeate the skin and be absorbed into the body, and the wearer may be
unaware that this is occurring.
When selecting a glove both factors must be considered together. A glove with
a short breakthrough time may be more suited to an application than another
with a longer breakthrough time, if the permeation rate is more favorable. ie less
chemical will get through the glove for the duration of the task. This is illustrated
below. Less chemical gets through with Glove 1 (5 minute breakthrough time +
low permeation rate) than with Glove 2 (15 minute breakthrough time + high
permeation), during a 30 minute task.
5
mins
30 mins
15
mins
Glove 1
Glove 2
For permeation rates and breakthrough times for glove materials contact the
glove manufacture or consult the MSDS of the chemical. Some manufacturers
will just give a rating to the glove rather than specific figures.
7.
WEARING, CLEANING AND DISPOSAL
Make sure hands are clean before putting on gloves.
Always inspect the glove prior to use for, wear, seam failure, cracking, bubbling,
swelling, cracking, tackiness and any holes or tears. Discard gloves with obvious
faults.
Great care must be taken to ensure that the inside surface of the glove is not
contaminated when gloves are put on and taken off.
Gloves used for handling chemicals (especially for intentional contact) should only be
reused with caution, and where it is within the manufacturer’s guidelines. Prior to the
removal of reusable gloves, wash any surface contamination from the glove with
warm soapy water and allow to air dry. Gloves may be periodically turned inside out
and the inner surface washed. Additional procedures for decontamination of gloves
where chemicals have permeated into the glove surface may be required, prior to
reuse. Refer to the manufacturer’s instructions.
Store gloves away from direct sunlight or extremes of temperatures.
Always wash hands after removing gloves, with warm soapy water, rinse thoroughly
and dry. Applying a hand moisturiser is also recommended.
Gloves used with chemicals may have to be disposed of as hazardous waste, if
chemicals have permeated into the glove material.
8.
PRE-EXISTING SKIN PROBLEMS
Some pre-existing skin conditions can effect the selection or use of gloves.
Cuts or abrasions on the hand are more suceptable to chemical attack. Always cover
cuts and abrasions with a waterproof plaster prior to putting gloves on and replace
after removal of gloves. Note, never use fabric plasters in the laboratory, they are too
absorbant.
Eczema sufferers may prefer to wear a cotton liner under gloves to avoid irritation
from sweat. Wash or replace liners regularly.
Anyone with a Latex allery should be provided with a non-latex alternative. Latex
allergies may cuase asthma attacks, anaphylatic reactions or a wide spread rash. If
someone is highly sensitive then other workers in the area should also avoid the use
of latex gloves. The use of powder free gloves is thought to minimise the risk of
developing a latex allergy in suseptable people.
9.
ALTERNATIVES TO USING GLOVES
As mentioned before, gloves are the least preferred control measure, and should only
be considered if other control measures are not suitable or do not minimize the risk
sufficiently.
Rather than immersing the hands into a chemical consider the use of forceps,
crucible tongs, baskets or other means or lowering and retrieving items.
A magnetic flea retriever negates the need to retrieve a magnetic flea with hands.
Dishwashers are a good alternative to washing glassware by hand.
10
EXAMPLES OF GLOVES TO HAVE ON HAND
In the school Science laboratory it is wise to have a variety of gloves on hand. I
recommend the following as a minimum requirement:
10.1
For the laboratory officer
 Nitrile disposable gloves for general chemical handling, where splashes
might occur
 Latex disposable gloves in the first aid kit and for use when cleaning up
microbiology practicals
 Ansell Super Glove – a latex and neoprene glove for general cleaning and
washing of glassware
 Leather gauntlets for removing hot items from ovens, incubators and
autoclaves
 Puncture, cut and abrasion resistant gloves for handling sharp metal,
broken glass and other sharp objects.
10.2
For Student classroom use
 Low powder Latex gloves for student use during dissections
 Cheap poly ethylene or poly vinyl gloves for messy task with nonaggressive chemicals eg paint, ink
11. GLOVE MATERIAL
The following table is taken from Glove Selection Guidance and lists glove material
and their advantages and disadvantages. Always refer to the manufacturer’s
specification.
12. GLOVE LABELLING AND PURCHASING
The Australian/New Zealand Standard 2161 describes the general requirements for
occupational protective gloves. It also defines the product and packaging labelling
requirements. Gloves must have trademark or manufacturer’s name, product code
and size. Packaging must also include where information about the product can be
obtained, a pictogram denoting performance levels and instructions for use.
Only gloves designed and tested for industrial use will have these pictograms.
Domestic gloves are generally not made and tested to the same standards and so
are not suitable for industrial use. Domestic gloves are often labeled “For minimal
risks only”.
The following Table of Pictograms is taken from A/NZ 2161.2
The following information gives details about the main pictograms for the Science
area:
12.1 Protection Against Mechanical Risks (AS/NZS 2161.3:2005)
The mechanical properties of the glove are shown by the following pictogram,
followed by performance level numbers relating to the four tests. There are 4 or
5 levels of performance for each test, Level 5 being the most resistance.
Note that gloves meeting the requirements for resistance to puncture may not
be suitable for protection against pointed objects such as hypodermic needles.
12.2 Protection Against the Cold (AS/NZS 2161.5:2005)
The cold protective properties of the glove are shown by the following pictogram
followed by performance level numbers relating to the three tests. There are
four levels of performance for each, Level 4 being the highest.
Tests
1.
Convective Cold
2.
Contact Cold
3.
Water Impermeability
12.3 Protection Against Thermal Risks (AS/NZS 2161.4:2005)
The thermal (heat and/or fire) protective properties of the glove are shown by
the following pictogram followed by performance level numbers relating to the
six tests. There are four levels of performance for each, Level 4 being the
highest.
Tests
1.
2.
3.
4.
5.
6.
Burning Behaviour
Contact Heat
Convection Heat
Radiant Heat
Small Splashes Of Molten Metal
Large Quantities Of Molten Metal
The following table gives temperature that the glove can withstand for Contact
Heat.
12.4 Protection Against Chemical and Microorganisms (AS/NZS 2161.10:2005)
The chemical protective properties of the glove are shown by the following
pictogram followed relevant code letters. Each letter in the code refers to a
particular chemical for which the glove has a breakthrough time of at least 30
minutes.
Waterproof gloves with low level chemical protection
(refer to packaging for further details)
12.5 For Minimal Risks Only
Gloves labelled “Comply with AS/NZS 2161.2”, but marked “for minimal risks
only’” have limited application in industrial situations. They should not be used
in applications with hazardous chemicals. They tend to give the wearer a false
sense of security, when in fact a chemical may quickly permeate the glove
material and expose the skin to a high concentration.
Definition of “For minimal risks only” from Annex A - AS/NZS 2161.2
“This category covers exclusively gloves intended to protect the wearer against
one more of:
- mechanical action whose effects are superficial (gardening gloves etc);
- cleaning materials of weak action and easily reversible effects (gloves
affording protection against diluted detergent solutions etc);
- risks wncountered in handling of hot components which do not expose
the user to a temperature exceeding 50oC or to dangerous impacts;
- atmospheric agents of a neither exceptional nor extreme nature
(seasonal clothing);
- minor impacts and vibrations which do not affect vital areas of the body
and whose effects cannot cause irreversible lesions.”
12.6 Purchasing
Appendix 1 shows a page from the Protector Alsafe Safety Catalogue showing
typical information provided for the purchaser. Note the pictograms and
performance level numbers. Additional information is usually available from the
manufacturer, who should be consulted prior to purchase.
GLOSSARY
Breakthrough time – the time elapsed between initial contact of a chemical with the
outside surface of the glove material and the time at which the chemical can be detected
at the inside surface of the material. Measured breakthrough times are dependent on the
sensitivity of the analytical methods used to detect the chemical.
Degradation – a deleterious change in the physical and/or chemical properties of a
protective glove material
Penetration – the movement of a substance and/or microorganisms through porous
materials, seams, pinholes, to other imperfections in a protective glove material on a
molecular level.
Permeation – the process by which a substance moves through a protective glove
material, on a molecular level. Permeation involves the following:
a) absorption of molecules of the substance into the contacted (outside) surface of a
material
b) diffusion of the absorbed molecules in the material
c) desorption of the molecules from the opposite (inside) of the material
Permeation Rate (steady state) – the relative constant rate with which a substance
permeates glove material after an initial period, expressed in mass of solvent per unit area
of glove per unit time.
MSDS – Material Safety Data Sheet
Appendix 1 – Protector Alsafe Catalogue
REFERENCES
AS/NZS 2161 - Occupational Protective Gloves
Part 1 – Selection, use and maintenance
Part 2 – General requirements
Part 3 – Protection against mechanical risks
Part 4 - Protection against thermal risks (heat and fire)
Part 5 - Protection against cold
Part 6 – Protective gloves for fire-fighters
Part 7 - Protection against cuts and stabs by hand knives
7.1 – Chainmail gloves and arm guards
7.2 – Gloves and arm guards made of other materials
7.3 – Impact cut test for fabric, leather and other materials
Part 8 - Protection against Ionizing radiation and radioactive contamination
Part 9 – Method of measurement and evaluation of the vibration transmissibility of gloves
at the palm of the hand
Part 10 – Protective gloves against chemicals and microorganisms
10.1 – Terminology and performance requirements
10.2 – Determination of resistance to penetration
10.3 - Determination of resistance to permeation by chemicals
Ansell Chemsafe Website
http://www.ansellchemsafe.com/default.aspx
Glove Selection Guidance, Imperial College London
http://www3.imperial.ac.uk/occhealth/guidanceandadvice/gloveinformationandguidance/glo
veselectionguidance
Protector Alsafe, Safety Catalogue, 2008