Personal protective equipment (PPE) is special gear used to protect the
wearer from specific hazards of a hazardous substance. It is a last resort
protection system, to be used when substitution or engineering controls
are not feasible. It should be understood that PPE does not reduce or
eliminate the hazard. It only protects the wearer and does nothing for
anybody else in the area or for any equipment exposed to the chemical.
PPE includes gloves, respiratory protection, eye protection, and protective
clothing. The need for PPE is dependent upon the type of operations and
the nature and quantity of the materials in use, and must be assessed
on a case by case basis. Workers who rely on PPE must understand the functioning,
proper use, and limitations of the PPE used.
Glove Selection And Use
Choosing the appropriate hand protection can be a challenge in a laboratory
setting. Considering the fact that dermatitis or inflammation of the
skin accounts for 40-45% of all work-related diseases, selecting the
right glove for the job is important.
Not only can many chemicals cause skin irritation or burns, but absorption
through the skin can be a significant route of exposure to certain chemicals.
Dimethyl sulfoxide (DMSO), nitrobenzene, and many solvents are examples
of chemicals that can be readily absorbed through the skin into the
bloodstream, where the chemical may cause harmful effects.
When Should Gloves Be Worn
Protective gloves should be worn when handling hazardous materials,
chemicals of unknown toxicity, corrosive materials, rough or sharp-edged
objects, and very hot or 
very
cold materials. When handling chemicals in a laboratory, disposable
latex, vinyl or nitrile examination gloves are usually appropriate for
most circumstances. These gloves will offer protection from incidental
splashes or contact.
When working with chemicals with high acute toxicity, working with
corrosives in high concentrations, handling chemicals for extended periods
of time or immersing all or part of a hand into a chemical, the appropriate
glove material should be selected, based on chemical compatibility.
Selecting the Appropriate Glove Material
When selecting the appropriate glove, the following characteristics
should be considered:
- degradation rating
- breakthrough time
- permeation rate
Degradation is the change in one or more of the physical properties
of a glove caused by contact with a chemical. Degradation typically
appears as hardening, stiffening, swelling, shrinking or cracking of
the glove. Degradation ratings indicate how well a glove will hold up
when exposed to a chemical. When looking at a chemical compatibility
chart, degradation is usually reported as E (excellent), G (good), F
(fair), P (poor), NR (not recommended) or NT (not tested).
Breakthrough time is the elapsed time between the initial
contact of the test chemical on the surface of the glove and the analytical
detection of the chemical on the inside of the glove.
Permeation rate is the rate at which the test chemical passes
through the glove material once breakthrough has occurred and equilibrium
is reached. Permeation involves absorption of the chemical on the surface
of the glove, diffusion through the glove, and desorption of the chemical
on the inside of the glove. Permeation rate is usually reported as E
(excellent), G (good), F (fair), P (poor) or NR (not recommended). If
chemical breakthrough does not occur, then permeation rate is not measured
and is reported ND (none detected).
Manufacturers stress that permeation and degradation tests are done
under laboratory test conditions, which can vary significantly from
actual end-use conditions. Users may opt to conduct their own tests,
particularly when working with highly toxic materials.
For mixtures, it is recommended that the glove material be selected
based on the shortest breakthrough time.
The following table includes major glove types and their general
uses. This list is not exhaustive.
| Glove Material |
General Uses |
| Butyl |
Offers the highest resistance to permeation by most gases and
water vapor. Especially suitable for use with esters and ketones.
Poor for aliphatic, aromatic hydrocarbons, halogenated hydrocarbons,
and gasoline. |
| Neoprene |
Good for acids and bases, peroxides, fuels, hydrocarbons, alcohols,
phenols. Poor for halogenated and aromatic hydrocarbons |
| Nitrile |
Excellent general duty glove. Provides protection from a wide
variety of solvents, oils, petroleum products, and some corrosives.
Excellent resistance to cuts, snags, punctures, and abrasions |
PVC |
Provides excellent abrasion resistance and protection from most
fats, acids, and petroleum hydrocarbons. Poor for most organics. |
| PVA |
Highly impermeable to gases. Excellent protection from aromatic
and chlorinated solvents. Cannot be used in water or water-based
solutions. |
Viton |
Exceptional resistance to chlorinated and aromatic solvents. Good
resistance to cuts and abrasions. |
Silver Shield |
Resists a wide variety of toxic and hazardous chemicals. Provides
the highest level of overall chemical resistance. |
| 4H |
Same as Silver Shield, but offers better dexterity. |
| Natural (Latex) rubber |
Good for very dilute acids and bases. Poor for organics. |
Where to Find Compatibility Information
Most glove manufacturers have chemical compatibility charts available
for their gloves. These charts may be found in laboratory supply catalogs
such as Fisher Scientific
and Lab Safety Supply.
Best Gloves offers copies of
their glove compatibility charts upon request. To obtain a copy, call
them directly at 800-241-0323. Best Gloves also offers an excellent
on-line database for glove selection at www.bestglove.com.
Most material safety data sheets (MSDS) recommend the most protective
glove material in their Protective Equipment section. There are MSDSs
for many laboratory chemicals available on the web through the EHS
home page.
EHS also has a computer program with glove compatibility information
for hundreds of chemicals. Contact EHS at 258-5294 for more information.
Other Considerations
There are several factors besides glove material to consider when selecting
the appropriate glove. The amount of dexterity needed to perform
a particular manipulation must be weighed against the glove material
recommended for maximum chemical resistance. In some cases, particularly
when working with delicate objects where fine dexterity is crucial,
a bulky glove may actually be more of a hazard.
Where fine dexterity is needed, consider double gloving with a less
compatible material, immediately removing and replacing the outer glove
if there are any signs of contamination. In some cases, such as when
wearing Silver Shield gloves, it may be possible to wear a tight-fitting
glove over the loose glove to increase the amount of dexterity allowed.
Glove thickness, usually measured in mils or gauge, is another consideration.
A 10-gauge glove is equivalent to 10 mils or 0.01 inches. Thinner, lighter
gloves offer better touch sensitivity and flexibility, but may provide
shorter breakthrough times. Generally, doubling the thickness of the
glove quadruples the breakthrough time.
Glove length should be chosen based on the depth to which
the arm will be immersed or where chemical splash is likely. Gloves
longer than 14 inches provide extra protection against splash or immersion.
Glove size may also be important. One size does not fit all.
Gloves which are too tight tend to cause fatigue, while gloves which
are too loose will have loose finger ends which make work more difficult.
The circumference of the hand, measured in inches, is roughly equivalent
to the reported glove size. Glove color, cuff design, and lining should
also be considered for some tasks.
Glove Inspection, Use and Care
All gloves should be inspected for signs of degradation or puncture
before use. Test for pinholes by blowing or trapping air inside and
rolling them out. Do not fill them with water, as this makes the gloves
uncomfortable and may make it more difficult to detect a leak when wearing
the glove.
Disposable gloves should be changed when there is any sign of contamination.
Reusable gloves should be washed frequently if used for an extended
period of time.
While wearing gloves, be careful not to handle anything but the materials
involved in the procedure. Touching equipment, phones, wastebaskets
or other surfaces may cause contamination. Be aware of touching the
face, hair, and clothing as well.
Before removing them, wash the outside of the glove. To avoid accidental
skin exposure, remove the first glove by grasping the cuff and peeling
the glove off the hand so that the glove is inside out. Repeat this
process with the second hand, touching the inside of the glove cuff,
rather than the outside. Wash hands immediately with soap and water.
Follow the manufacturer’s instructions for washing and caring
for reusable gloves.
Latex Gloves and Related Allergies
Allergic reactions to natural rubber latex have been increasing since
1987, when the Center for Disease Control
recommended the use of universal precautions to protect against
potentially infectious materials, bloodborne pathogens and HIV. Increased
glove demand also resulted in higher levels of allergens due to changes
in the manufacturing process. In additional to skin contact with the
latex allergens, inhalation is another potential route of exposure.
Latex proteins may be released into the air along with the powders used
to lubricate the interior of the glove.
In June 1997, the National Institute of Occupational Safety and Health
(NIOSH) issued an alert Preventing
Allergic Reactions to Latex in the Workplace
NIOSH studies indicate that 8-12% of healthcare workers regularly exposed
to latex are sensitized, compared to 1-6% of the general population.
Latex exposure symptoms include skin rash and inflammation, respiratory
irritation, asthma and shock. The amount of exposure needed to sensitize
an individual to natural rubber latex is not known, but when exposures
are reduced, sensitization decreases.
NIOSH recommends the following actions to reduce exposure to latex:
- If latex gloves must be used, choose reduced-protein, powder-free
latex gloves.
- Whenever possible, substitute another glove material.
- Wash hands with mild soap and water after removing latex gloves.
Although latex gloves remain a popular glove in some laboratories,
they do not offer good protection from many chemicals, including ethidium
bromide. Consider nitrile or chloroprene gloves as an alternative.
ventilation
or a fume hood, are not feasible or do not reduce the exposure of a
chemical to acceptable levels. The use of a respirator is subject to
prior review by EHS, according to University policy, since their use
is regulated by the 
are far stronger than standard street wear glasses. Safety glasses
must have side shields and should be worn whenever there is the possibility
of flying particles, glass, powders, etc. entering the eye. Standard
street wear eyeglasses fitted with side shields are not sufficient.
Workers
who are interested in obtaining prescription safety glasses should
contact EHS at 8-5294. 
shorts),
torn clothing and unrestrained hair may pose a hazard in the laboratory.
Open-toed shoes or cloth sneakers should not be worn in laboratories
or where mechanical work is performed
