Personal protective equipment (PPE) is necessary to work with most hazardous materials and/or to perform certain experiments. It is a last resort protection system, to be used when substitution or engineering controls are not feasible. It may also be necessary to supplement the safety equipment in laboratories such as the fume hoods. PPE does not reduce or eliminate the hazard, protects only the wearer, and does not protect anyone else.
PPE includes gloves, eye protection, respiratory protection and protective clothing. The type of PPE required is highly dependent upon the nature of the experiment and the hazards associated with the material being used. However, the minimum requirements for any laboratory work done at Concordia University are the following:
- safety glasses
- lab coat
- long-sleeved and long-legged clothing worn underneath the lab coat
- closed shoes
Eye Protection
Safety Glasses
Wearing eye and face protection is necessary to protect against splashing chemicals, biological materials and flying particles. Eye protection in the form of glasses, goggles or face shields is available and the choice will depend on the risk involved with the experiment or the type of material being used. The worker should consult the experiment SOP or the MSDS to choose the right type of protection in accordance with the CSA standard for Industrial Eye and Face Protectors Z94.3. The information in the Z94.3.1 “Protective Eyewear: A User's Guide” by Canadian Standards Association is also a good source of information or contact your supervisor or EHS.
Safety glasses must have side shields and must be worn whenever there is the possibility of objects striking the eye, such as particles, glass, or metal shards. Many potential eye injuries have been avoided by wearing safety glasses. If prescription safety glasses are to be worn in the laboratory, they must be equipped with side-shields in order to provide appropriate protection. Regular prescription glasses are not considered safety glasses. If regular prescription glasses are used, special safety glasses designed to fit over them must be worn.
However, safety glasses do not provide adequate protection against chemical splashes, aerosols or dusts/powders. They do not seal to the face, resulting in gaps at the top, bottom and sides, where chemicals may seep through. If such hazards are present in the laboratory work, goggles are best suited for this type of potential exposure.
Chemical Splash Goggles
Chemical splash goggles should be worn when there is potential for splash from a hazardous material, such as working with solvent and highly corrosive materials. Chemical splash goggles should be impact resistant and have indirect ventilation so hazardous substances cannot drain into the eye area. Some can even be worn over prescription glasses.
Face Shields
Face shields are to be used when working with large volumes of hazardous materials, such as highly corrosive substances, either for protection from splash to the face or flying particles. Face shields along do not provide sufficient eye protection; they must be used in conjunction with safety glasses or goggles.
Contact Lenses
- Contact lenses may be worn in the laboratory, but do not offer any protection from chemical contact. Therefore, lab workers wearing contact lenses must comply with the same rules in terms of eye protection.
- Lab workers should be aware of the following :
- You should advise their supervisors.
- You may have to remove lenses to perform certain experiments.
- Plastic used for contact lenses is permeable to some vapours found in a laboratory. Such vapours can be trapped behind the lens and may cause extensive irritation to the eye.
- If a contact lens becomes contaminated with a hazardous chemical, rinse the eye(s) using an eyewash station and remove the lens immediately.
- Contact lenses that have been contaminated with a chemical must be discarded.
Protective Clothing
Lab coats are required in all laboratories. These are available in various designs and materials and the choice should depend on the type of work being done and the risks involved. The typical lab coat is a knee length cotton-blend with long sleeves and front closure. Lab coats are appropriate for minor chemical splashes and solids contamination.
If highly toxic or corrosive liquids are to be used, rubber aprons and chemical smocks offer improved protection over regular lab coats. Disposable outer garments (i.e., Tyvek suits) may be useful when cleaning and decontamination of reusable clothing is difficult. Long-sleeved and long-legged clothing should be worn beneath the lab coat to protect the skin in case of a spill. For best protection a lab coats should be knee length, have long sleeves to the wrist and be buttoned up. Shorts and skirts should not be worn when working in a laboratory. Contaminated lab coats should not be washed at home with other laundry. A cleaning service is provided by certain departments.
Footwear
Closed-toed shoes should be worn at all times in laboratories where chemicals are stored or used. Sandals, high heel shoes, canvas toed shoes, as well as open-toed and open-backed shoes should be avoided due to the danger of spillage of corrosive or irritating chemicals and broken glass. Chemical resistant overshoes or boots may be used to avoid possible exposure to corrosive chemical or large quantities of solvents or water that might penetrate normal footwear (e.g., during spill cleanup).
Gloves
Skin contact is a potential source of chemical exposure. Protective gloves should be used to prevent the potential exposure to chemicals or biological hazards. The proper type of glove will depend on the materials being used. The MSDS is an important source of information for proper glove selection. Different glove types have different chemical permeability, therefore you can check with the manufacturer’s compatibility chart before choosing a specific glove type. Understanding the terms used in glove compatibility charts is primordial.
- Breakthrough time: Time it takes for the chemical to travel through the glove material. This is only recorded at the detectable level on the inside surface of the glove.
- Permeation Rate: Time it takes for the chemical to pass through the glove once breakthrough has occurred. This involves the absorption of the chemical into the glove material, migration of the chemical through the material, and then de-absorption once it is inside the glove.
- Degradation rating: This is the physical change that will happen to the glove material as it is affected by the chemical. This includes, but is not limited to, swelling, shrinking, hardening, cracking, etc. of the glove material.
Compatibility charts rating systems will vary by the manufacturer’s design of their chart. Many use a color code, where red = bad, yellow = not recommended, green = good, or some variation of this scheme. A letter code may be used, such as E + excellent, G = Good, P = poor, NR = Not Recommended. Any combination of these schemes may be used, so please understand the chart before making a decision on the glove to be used.
The following document includes major glove types and their general uses. This list is not exhaustive.
Gloves Types and Uses
Other Considerations
- Level of dexterity: Where fine dexterity is crucial, a bulky glove may actually be more of a hazard. 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: 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 care: All gloves should be inspected for signs of degradation or puncture before use. 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.
Latex gloves
The use of latex gloves has been associated with an increased sensitization and the development of allergy symptoms over the last decades. Such 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. Disposable latex gloves offer poor protection against chemicals and are not recommended to be used in the laboratory environment. However, if latex gloves must be used, choose reduced-protein, powder-free latex gloves and wash hands with mild soap and water after removing latex gloves.
Allergies
As research facilities have increasingly moved away from latex exam gloves because of their well-known allergy-related symptoms, other types of skin irritation and allergy to non-latex gloves have also increased. Some people can potentially develop an allergic contact dermatitis with the use of nitrile gloves, mainly caused by chemical accelerators used in the production of nitrile and other latex-free gloves. While vinyl gloves may be an option in some circumstances, they lack the elastic quality of nitrile and latex gloves, and do not provide the same level of protection. Alternative glove options are available from different suppliers against nitrile and latex allergies such as:
- accelerator-free nitrile gloves
- nitrile with aloe gloves, which are easier on the skin
- cotton liners (for sweaty hands too): they put a barrier between the glove and the skin and also absorb some of the moisture, which can also give a rash
- Neo-Pro gloves (Neoprene chloroprene)
