PPE: The Last Line of Defense
Personal Protective Equipment (PPE) is considered the last line of defense against safety hazards, such as a chemical or biological exposure or a physical safety hazard. Since PPE can fail, those who wear PPE must be trained to understand its limitations. In order for PPE to protect the user, it must be stored, maintained and worn properly. When working with hazardous materials, always consider substituting a non-hazardous or less hazardous material before reaching for PPE.
Personal protective equipment does not eliminate the hazard. The need for PPE is dependent upon the type of operations and the nature and quantity of the materials in use. The choice of PPE if often procedure-specific. There is not one type of glove that can protect against all hazards. Be sure to complete a hazard assessment before choosing or recommending PPE.
Examples of PPE include:
A hazard assessment (often called a Risk Assessment) should be conducted:
- before any new procedure is started,
- when a procedure changes in any way, and
- when personal protective equipment needs to be chosen.
A hazard assessment helps to determine the best means of eliminating or reducing potential risks in order to prevent injury or illness. The Hierarchy of Controls (below) shows the recommended method for controlling safety hazards. Contact email@example.com to help you assess the hazards of a particular procedure or situation in your lab or work area.
The hierarchy of hazard controls emphasizes the controlling of any hazard at its source. After elimination and substitution, the hierarchy of controls includes:
- Engineering Controls
- Administrative Controls
- Personal Protective Equipment
Engineering controls may include using a chemical fume hood, task-oriented ventilation such as a snorkle, a biosafety cabinet or increasing the ventilation in a particular area to minimize an exposure to a hazardous substance. A hazardous substance may include a vapor, fume, gas, dust. It may also include a biological or nano material that may aerosolize particles.
Administrative controls includes altering the way in which a procedure is done, monitored and/or restricted. Examples include restricting the time that a student or worker is exposed, creating written standards operating procedures, enforcing rules about daily housekeeping, performing regular equipment maintenance or instituting strict personal hygiene practices.
Personal protective equipment should only be considered as a supplemental control when engineering controls are not adequate. PPE should also be on hand for use during an emergency response and cleanup procedures and can be used to increase the level of safety protection from chemical, biological and physical hazards in case an unexpected event occurs.
Supervisors are responsible for determining what type of personal protective equipment should be used for specific procedures and operations. PPE should be chosen based on the hazard(s) being encountered. Examples of the types of hazards from which one may need protection may include:
- a chemical (flammable, corrosive, toxic , reactive)
- a biological material
- an impact, compression or penetration,
- heat or cryogenic material
- a harmful dust
- light (optical radiation)
- sharp objects
Personal protective equipment comes in varying sizes. Supervisors must be sure to order an assortment to fit students or staff so that different size individuals may be accommodated. Material Safety Data Sheets can help to determine what PPE is recommended. However, MSDSs do not always offer the most up to date information nor do they provide specific recommendations. Risk Management and Safety (ES) staff is available to help determine which kind of PPE is appropriate for specific procedure and activities. Be sure to document specific PPE choices on the Chemical Use Planning Forms for your lab.
The use of any type of personal protection equipment requires adequate training. The overall goal of PPE training is to protect the wearer from physical hazards (biological, chemical, radioactive) and to prevent injury from improper use or equipment malfunction. Supervisors are responsible for providing training to those who wear PPE under their guidance. Users must, at a minimum, be trained about the following:
– When and what PPE is necessary;
– How to properly don, doff, adjust, and wear PPE;
– The limitations of the PPE chosen; and,
– The proper care, maintenance, useful life and disposal procedure for the chosen PPE.
PPE training should be documented and kept in the laboratory safety notebook.
All personal protective equipment has limitations. This is why PPE is the referred to as the last line of defense.
- Takes time to put it on
- Can limit certain movements
- Can limit field of vision
- Can cause difficult communication (e.g respirator, a face shield)
- Can be used improperly causing false sense of security
- Must be maintained properly to be effective
- Can be penetrated by hazardous agents
- Can become contaminated and must be changed out
- Wearers may become contaminated as they remove PPE unless decontamination and removal protocols are followed carefully
- Can cause hands or face to sweat
First: Determine the Hazard
What is the main hazard that you are trying to protect your hands from? Are you concerned with protection from hazardous chemicals, biological materials, radioactive materials, sharp objects, cryogenic liquids, heat or a combination of these? Also, consider the length of time that your skin may potentially be exposed to the hazard.
Gloves are made of different polymers including latex, nitrile rubber, vinyl and neoprene. Nitrile gloves are by far the most common gloves used in research laboratories on campus.
Never use latex gloves if your main concern is chemical protection. Latex can cause serious allergies in some people. In general, Safety staff discourages its use. The protein in latex rubber can cause an allergic reaction to individuals who may be sensitive to it. Symptoms can range from sneezing to anaphylactic shock, a serious condition that requires immediate medical attention. A latex allergy can also develop over time after wearing latex gloves.
The Center for Disease Control (CDC) has more information for those interested in latex allergies.
Thin (4-5 mil) latex ‘exam’ gloves have been tested for use with chemicals and should NOT be worn for use with hazardous chemicals. Be sure that you know the thickness of the glove you are using.
Powdered Gloves vs Non-Powdered: Gloves come powdered or un-powdered. The powder is usually cornstarch and is used to to lubricate the gloves, making them easier to put on ones hands.
Steps To Choosing The Right Glove
Look at glove selection guides in catalogues or web sites of various scientific and safety suppliers. Gloves are rated for degradation, breakthrough, and permeation rates. Choose a glove that provides the best resistance to the chemical being used. For some hazards, double-gloving may be needed. (e.g. the new recommended glove for handling dimethyl mercury is a highly resistant laminate glove (Silver-Shield or 4H), which has no abrasion/cut resistance, worn underneath a pair of long cuffed unsupported neoprene, nitrile, or similar heavy-duty glove.) See more on nitrile gloves below.
Protection from biological hazards may be simple or complex dependent on whether the biological material is immersed in something other than water.
Gloves provide a necessary personal protection barrier and help prevent scatter contamination. Glove selection is based on the carrier material (i.e. water, toluene, etc.). (Radioiodination procedures require double gloving.)
Chemical compatibility guides may not indicate susceptibility to abrasion or cuts. You will need to check Mfg. or supplier for this information.
Animal Bites/Scratches Hazard
Mice, rodents and other animals can scratch and bite. Wear appropriate gloves when handling animals. Look at
websites such as http://www.hexarmor.com/industries/animal-handling-vets/ and
Wear proper glove when handling welding torches or grabbing sterilized materials from a hot autoclave. Muffle furnaces on high temps or removing fired pottery from a raku kiln all need specialized gloves to prevent burns.
7. Cryogenic hazards
8. Combination Hazard
Selection guides normally list gloves by the protection they provide from one "pure" chemical, not a combination.
In this case selection should be based on the component with the shortest breakthrough time.
For using small amounts of chemicals, consider using an all-purpose glove, such as a Best® N-Dex® Original Powder-Free Nitrile Glove. Glove manufacturer's should be able to provide you with a glove degradation chart that shows how fast a chemical can permeate the glove material. "Best" is one company that can provide a glove degradation chart that recommends a specific type of glove for specific chemicals.
Keep these guidelines in mind as you consider your glove selection:
- Consult manufacturers’ glove selection charts to determine which gloves will best protect you. However, be aware that our experience has been that some glove manufacturers’ selection guides are incomplete and misleading.
- Safety staff recommend that the minimum protective glove for general chemical work is a 4 or 5 mil nitrile glove for several reasons. These gloves are reasonably priced, and having one glove for general use takes the guesswork out of glove choice when multiple types are available in the laboratory and the use of nitrile prevents the development of latex allergies from occupational exposure.
- Glove thickness is an important consideration in protection from skin exposure. For example, we have not been able to find a 4 mil latex glove that has been tested for use with hazardous chemicals. An 8 mil latex glove may protect better than a standard 4-5 mil nitrile glove, but is much more expensive.
- Do not buy a glove that does not specify the thickness of the glove material.
- Gloves come in several sizes (S, M, L, XL). Buy a variety so they will comfortably fit all lab personnel.
- Pay attention to whether glove selection guides are based on incidental contact with the chemical or immersion. For laboratory work most guides recommend incidental contact which requires removal of the glove upon contamination, washing your hands, and putting new gloves put on.
Rules for glove use in the labs:
- Wear the correct gloves as needed.
- Wear gloves no longer than 2 hours.
- Wash hands once gloves have been removed.
- Disposable gloves must be discarded once removed. Never save for future use.
- Dispose of gloves into the proper container (biologically contaminated gloves will need to go into a red bag); while other chemically contaminated gloves must be collected as hazardous waste.
- Non-disposable/reusable gloves must be washed and dried, as needed, and then inspected for tears and holes prior to reuse.
- Remove gloves before touching personal items, such as phones, computers, pens and one’s skin.
- NEVER wear gloves out of the lab. If gloves are needed to transport anything through hallways, use a secondary container and carry clean gloves in your hand to put on when you arrive at your new location.
- If for any reason a glove fails, and chemicals come into contact with your skin, consider it an exposure and seek medical attention.
To minimize exposure to chemicals or biological agents, proper clothing and/or protective laboratory equipment, such as laboratory coats or protective aprons, should provide reasonably complete coverage of the skin and clothing. Best practice is to wear a knee length, long sleeved laboratory coat when working with hazardous chemicals. It provides a protective layer for bare skin and can be easily removed upon contamination or in the event of an accident. Such equipment should be regularly laundered to prevent buildup of contamination.
The presence of certain physical hazards or other specific elements of the procedure may dictate caution in the choice of style so as to not create additional hazards, for example, short sleeves may be preferable if there is a possibility that long sleeves could get caught in a mechanical operation.
Disposable Lab Coats are now available at the Biology stockroom in Marsh Life Science.
Cleaning Lab Coats
Never take lab coats home or to a local laundromat to launder them. Lab groups can contract with a local uniform or laundering service that has the capability of laundering laboratory coats. Contact firstname.lastname@example.org if you need information on what companies provide this service locally.
Eye and face protection is required whenever there is reasonable probability that an injury to the eye or face can be prevented or reduced. Eye and face protection can prevent accidental splashes of hazardous chemicals or a biological material. It can also prevent an unexpected flying particles (chips or shards) from someone nearby using a machine or hand tool. Eye and face protection must meet the ANSI Standard Z87.1.
Types of Eye Protection include:
- Safety Glasses with side shields that conform to ANSI standard Z87.1-1989 (approved glasses will have the standard number imprinted on the frames). Safety glasses come in many different styles. They should fit well around the eye area. If large gaps are present around the eyes or slippage occurs, try another style.
- Safety Goggles and/ Face Shields should be worn if there is a risk of splash from a hazardous material. They should also be worn when working with high risk chemicals or processes such as highly reactive chemicals, concentrated corrosives, or with vacuum or pressurized glassware systems.
- Tinted or shaded lenses can be worn for protection from radiant energy (lasers, welding).
Prescription glasses are not acceptable eye protection. Safety glasses or goggles should be worn over prescription glasses to offer proper protection.
Wearing Contact Lenses In The Lab
Injury data are lacking to clearly indicate that contact lens wear should be restricted during work with hazardous chemicals; however eye protection is always necessary. Wearing contact lenses under some circumstances can provide the worker with a greater choice in eye and face protection as well as more visual acuity. NIOSH has published a bulletin called Contact Use In A Chemical Environment that may provide more guidance for those who wear contact lenses in the laboratory.
Bare feet, sandals and open toed shoes are not permitted while working in UVM laboratories. There is often the potential for an exposure to chemical and physical hazards. Wear substantial shoes that can provide protection from heavy objects falling or rolling on to your toes or from an object piercing your feet from below. Shoes with open backs are allowed at the discretion of the Supervisor.
Respirators are used to eliminate hazards such as dusts, fogs, fumes, mists, gases, smoke, sprays and vapors. A hazard assessment must be completed for those working in environments with these types of hazards.
Supervisors or instructors requiring students to wear respirators must contact UVM Training & Compliance Office (TCO) to make sure students can be medically cleared, trained and fit tested before using respirators. Please contact UVM Training & Compliance to submit a Respirator Request Form.
Fit testing takes place at TCO's facility in Fort Ethan Allen in Colchester. There is a CCTA bus that goes to the TCO facility. Take CCTA Bus #2 from the Fletcher Allen Health Care oval; it drops you off near their front door.
Hearing loss is a common workplace injury. It is often ignored because it happens gradually over a period of time. Ear plugs or ear muffs offer the most protection. Ear protection receives a Noise Reduction Rating (NRR). This is the measurment, in decibels, of how well a hearing protector reduces noise as specified by the EPA.
The higher the NRR number the greater the noise reduction. While wearing hearing protection your exposure to noise is equal to the total noise level minus the NRR of the hearing protectors in use. For example, if you were exposed to 80db of noise but were wearing earplugs with an NRR of 29, your actual noise exposure would only be 51dB.
Protective helmets are required when working in areas where there is a potential for injury to the head from falling objects.
Hard hats are tested for impact and penetration resistance from blows to the top of the head, flammability resistance, and water absorption.