Chapter 3: Controls for Mitigating Laboratory Hazards

3.1 Hierarchy of controls

The hierarchy of controls prioritizes hazard mitigation strategies on the premise that the best way to control a hazard is to systematically eliminate it from the workplace or substitute a less hazardous technique, process, or material. If elimination or substitution are not feasible options, engineering controls, administrative controls, and PPE must be used to provide the necessary protection. 

3.2 Engineering controls and safety equipment

The implementation of engineering controls to reduce risk should be the first consideration if a hazard cannot be eliminated or substituted. For example: 

3.2.1 Chemical fume hood

Although laboratory spaces are designed with consideration for air circulation and ventilation, the general air handling system does not provide adequate worker protection when working with most hazardous chemicals. When used correctly, a chemical fume hood can prevent harmful exposures when working with hazardous chemicals in the laboratory. The need for a chemical fume hood can be determined by consulting the safety data sheet (SDS) for the chemicals you are working with. Some SDS terminology, as listed below, indicates a need for using a chemical fume hood or other ventilation control:

• use with adequate ventilation
• avoid vapor inhalation
• provide local exhaust ventilation
• use in a chemical fume hood

Proper use of a chemical fume hood requires:

• working with the sash at the correct height as determined by the most recent inspection;
• keeping all apparatus at least 6 inches back from the face of the hood and keeping the slots in the hood baffle free of obstruction;
• elevating large equipment at least two inches off the base of the fume hood, to allow for the passage of air underneath the apparatus;
• minimizing movement and other forms of potential air disturbances past the face of the hood while you are working;
• eliminating sources of ignition inside the hood when flammable liquids or gasses are present;
• limiting the storage of chemicals and apparatus in the hood to those that are required for current work;
• Keeping the hood sash closed at all times except when the hood is in use.

Contact Facilities Management if the hood does not appear to be operating correctly. Chemical fume hoods are inspected annually by Michigan Tech Facilities Management staff members. During the inspection, the maximum correct working height of the sash is marked to indicate the maximum sash height allowed while still maintaining the recommended safe air flow. Do not work in a chemical fume that has not been inspected within the past year or does not have the safe sash height marked.

Other types of chemical fume hoods
There are many other types of chemical fume hoods designed for specific functions and uses:

Perchloric acid fume hood: designed with a water wash-down system in the ductwork to prevent the build-up of corrosive and explosive perchlorates.

Radioisotope fume hood: designed with HEPA and charcoal filters to prevent radioactive particles from entering the ductwork.

Walk-in fume hood: extend to the floor to allow for large equipment to be easily moved into the hood. Despite their name they are not designed to allow you to "walk in" and do work inside the hood.

California or distillation hood: A free standing hood with access to equipment from two sides and designed to operate with the sashes in the closed position.

3.2.2 Glove box

A glove box is a sealed container that is designed to allow one to handle material in a defined atmosphere (typically inert). Gloveboxes can be used to protect sensitive items inside or the user on the outside, or both. The following recommendations should be followed by all personnel using a glove box:

• Before any work in a glove box occurs, all personnel must receive training and must understand the design features and limitations of a glove box before use. Training must include detailed instruction on elements such as the ventilation and vacuum controls that maintain a pressure differential between the glove box and outside atmosphere and atmospheric controls (e.g., controlling oxygen concentrations and moisture). Training records should be kept in the laboratory or department.
• Prior to use, a visual glove inspection must be performed. Gloves should not be used until they fail: they should be changed according to the glove box manufacturer’s recommendations or whenever necessary. Changing of a glovebox gloves should be documented (date, manufacturer, model of glove, and person performing change). Records of glove changes and other maintenance should be kept in the laboratory or the department.
• Plugging ports that are never or infrequently used is recommended. A properly plugged port should have a stub glove and a glove port cap installed.
• Chemical resistant gloves (e.g., disposable nitrile gloves) should be worn inside the glove box gloves to protect from possible contamination.
• If the glove box is equipped for pressure measurement, the pressure must be checked every day, before use and immediately after gloves are changed. The pressure check must be documented and kept with other records supporting the glove box.
• Keep sharps in an approved container while in the glove box.
• Do not work in the glove box unless the lighting is working.
• Follow all safe work practices for using and handling compressed gas that may be associated with working in the glove box.
• All equipment and chemicals in the glove box must be organized and all chemicals must be labeled. Do not allow items, particularly chemicals, to accumulate in the glove box.

3.2.3 Biological Safety Cabinet (BSC)

A biological safety (or biosafety) cabinet (Figure 3.2.3) is an enclosed, ventilated laboratory workspace for safely working with infectious and potentially infectious biological materials. All biological safety cabinets on campus must be certified by a trained technician on an annual basis. There are several different types of biological cabinets each designed for specific uses. All biological safety cabinets are designed to protect researchers from exposure to infectious materials. Some are also designed to prevent contamination of samples inside the cabinet. Most are not designed for use with chemical applications. If you are unsure about the type of biological safety cabinet you are using and its proper use, contact EHS. 

3.2.4 Laminar flow clean bench

A laminar flow clean bench (Figure 3.2.4) DOES NOT provide worker protection and SHOULD NOT be considered as a method for controlling exposure to chemical or biological or other hazardous materials. These workspaces are specifically designed to prevent contamination of semiconductor wafers, samples, and other materials that are sensitive to contamination.

3.2.5 Other engineering controls

Other examples of engineering controls include splash guards and other barriers to prevent contact with the hazardous chemicals; tongs and other devices for manipulating hazards, self- closing containers; self-sheathing needles and scalpels; guards on moving parts and interlocks to automatically disconnect power when safety covers are removed.

3.3 Administrative controls

3.3.1 General rules for laboratory work with chemicals

Safe work practices are essential to laboratory safety. They must be understood and followed by all persons working with potentially hazardous chemicals and equipment in the laboratory. In addition to written SOPs, laboratories are required to develop or adopt general laboratory safety rules and policies and, like SOPs must also be written and enforced. General rules for laboratory safety taken from the OSHA/MIOSHA laboratory standard include:

• Regular work schedules should be followed unless a deviation is authorized by the laboratory supervisor; 
• Unauthorized experiments should not be performed;
• Plan safety procedures before beginning any operation;
• Follow Standard Operating Procedures at all times;
• Always read the Safety Data Sheet and label before using a chemical;
• Wear appropriate lab attire: long pants, closed-toe shoes, no loose or baggy clothing, no scarves, neckties, jewelry, etc., long hair should be tied back and/or styled to prevent accidental contact with hazardous chemicals, materials, and equipment;
• Always wear appropriate PPE when working in the laboratory;
• Use appropriate ventilation when working with hazardous chemicals;
• Pipetting should never be done by mouth;
• Hands should be washed with soap and water immediately after working with any laboratory chemicals, even if gloves have been worn;
• Eating, drinking, gum chewing, applying cosmetics, and taking medicine in laboratories where hazardous chemicals are used or stored is strictly prohibited;
• Do not store food, beverages, cups, and other drinking and eating utensils in areas where hazardous chemicals and materials are handled or stored (if these items are used as part of an experiment, they must be clearly labeled with “NOT FOR HUMAN CONSUMPTION” or a similar warning);
• Laboratory refrigerators, ice chests, ice flakers, cold rooms, and ovens should not be used for food storage or preparation;
• Contact the laboratory supervisor/PI, departmental CHO/safety officer/liaison or EHS office with safety questions or concerns;
• Know the location and proper use of safety equipment;
• Maintain awareness of your surroundings (no listening to music using headphones, earbuds);
• Inform others working in the laboratory of the hazards associated with your work;
• Notify supervisors of chemical sensitivities or allergies;
• Report all injuries, accidents, incidents, near misses and unsafe conditions to the Laboratory Supervisor, the departmental CHO/safety officer/liaison or EHS;
• Unauthorized persons are not allowed in the laboratory;
• Properly dispose of chemical wastes.

These simple, somewhat "common sense" rules are important. If basic rules are followed, it is more likely that other, more complex and perhaps less intuitive, safety procedures will also be followed.

Examples of additional general safety rules and policies may be found in various sources including "Prudent Practices in the Laboratory" written by the National Research Council.

3.3.2 Laboratory security

All laboratory personnel have a responsibility to protect university property from misuse and theft of hazardous materials, particularly those that could threaten human health. The following minimum security measures pertain to all campus laboratories:

• The laboratory door must remain closed at all times and closed and locked when not occupied;
• Only individuals authorized by University policy and by the laboratory supervisor are permitted in laboratories (contact the Lab PI, Department Chair, or Public Safety and Police Services if unauthorized individuals refuse to leave the laboratory when asked);
• If you see anything suspicious or someone displays suspicious behavior, immediately report it to the Michigan Tech Public Safety and Police Services;
• Particularly hazardous chemicals must be secured at all times.

3.3.3 Labeling chemical containers in the laboratory

Every chemical container in the laboratory, whether hazardous or not, must be properly labeled.

3.3.3.1 Chemicals in original containers

The OSHA hazard communication standard (29CFR1910.1200.f) requires chemical manufacturers and distributors to label chemical containers with the following information:

• Product Identifier (name of the chemical);
• Signal Word (either “Danger” or “Warning” to indicate the relative severity of the hazards associated with the chemical);
• Hazard Statement(s) (a specific description of the nature and degree of the hazard);
• Precautionary Statement(s) (recommendations for minimizing/preventing exposure; responding to emergencies; proper storage and disposal of the chemical);
• Pictogram(s) (graphic symbols communicating information about the chemical’s hazards);
• Name, Address and Telephone Number of the manufacturer/distributor; 

In the laboratory the following information shall be added to the label:

• The date the chemical is received in the laboratory;
• The name of the person receiving the chemical or other laboratory identifiers such as the PI's name or room location;
• The date the chemical is opened (this is extremely important for ethers and other potentially reactive chemicals);

Do not remove or deface the manufacturer’s original container label while the container is being used hold its original contents. If any information on the label becomes illegible, a new label with the same information must be created and affixed to the container.

3.3.3.2 Chemicals in secondary containers

All secondary chemical containers (e.g., bottles, beakers, flasks, sample vials, wash bottles, or any other container holding a chemical that is not for immediate use or is left unattended for any length of time) shall be labeled with: 

• The full name of the chemical (abbreviations, chemical formulae, or structures are NOT acceptable unless there is a complete and up-to-date legend (e.g., MeOH = Methanol) prominently posted in the laboratory);
• The concentration of the chemical (e.g. 70% ethanol, 2M sodium chloride, 10% bleach in water, etc.,); 
• A description of any hazards associated with the chemical (e.g. “flammable,” “corrosive,” “toxic,” etc.) using words or GHS pictograms; 
• The date the chemical was placed into the container;
• The name of the person responsible for the chemical;

Secondary container labels must be legible and durable so that the information cannot be easily washed off or stained. If any information on the label becomes illegible, a new label with the same information must be created and affixed to the container.

NOTE: Hazardous Waste collection containers have their own set of labeling rules.

3.3.3.3 Research samples and chemicals developed in the lab

• Research samples, reagents, and chemicals created or used in the lab must be labeled as described above for secondary containers (chemical name, concentration, associated hazards, date created/collected/received, and responsible person).
• The labeling requirements for individual samples in a set or group of samples may be modified if the samples are stored together in larger containers that are labeled with all the information listed above. For example, samples in small tubes or vials may be consolidated and stored together in an appropriately labeled secondary container. 
• Store samples in appropriate containers and according to compatibility and primary hazard class. At a minimum, determine the hazardous characteristics of the sample (flammable, corrosive, oxidant, reactive, etc.) and store accordingly. An example of a system for segregating chemicals according to compatibility can be found on the Grainger website.
• Properly dispose of samples as soon as they are no longer needed. The accumulation of unnecessary samples in the laboratory creates housekeeping issues, reduces laboratory efficiency and storage capacity, and may incur higher costs for disposal.
• If a chemical substance or sample is created or produced for another user outside of the lab, the laboratory supervisor must comply with the Hazard Communication Standard including the requirements for preparation of SDSs and container labeling.

3.3.4 Laboratory safety culture

The goal of any experimental design is to deliver useful data in an efficient and timely manner, without delays or incident. Some of the first considerations for an experiment design or modification are the use of potentially hazardous chemicals; the use of potentially dangerous equipment; and the potential injury they may cause. One rule-of-thumb is to assume that incidents, e.g., chemical spills, fires, etc., will happen and plan accordingly. This will drive decisions to:

• Eliminate a particularly hazardous chemical or process;
• Substitute a hazardous material for one that is less hazardous;
• Minimize quantities of experimental chemicals;
• Enclose processes in fume hoods or provide other local ventilation;
• Place guards, screens, or barriers between the hazard and the researcher and other prudent practices;
• Mandate personal protective equipment; 

Be fully aware of the risks in the laboratory. A good working knowledge about the hazards of chemicals used in the research and the potential dangers of any equipment is critical. Read and understand the product safety warnings on research equipment and hazardous chemical labels.

Principal Investigators / Laboratory supervisors must:

• Thoroughly review Safety Data Sheets for chemicals that staff, students, and postdocs are using, so that they can discuss specific hazards and safeguards; 
• Consider how to train the staff, students, and postdocs to assure they retain the knowledge;
• Think about the response and performance expected from the staff, students, and postdocs if an incident occurs; 
• Correct those who do not follow standard safety precautions, or disregard good laboratory practices. 

The following tips reproduced verbatim from the National Academy of Sciences “Prudent Practices in the Laboratory” will help to create a culture of safety within an academic laboratory: 

• Make [the] topic of laboratory safety an item on every group meeting agenda. 
• Periodically review the results of laboratory inspections with the entire group. 
• Encourage students and laboratory employees to contact the EHS office if they have a question about the safe methods of handling hazardous chemicals. 
• Require that all accidents and incidents, even those that seem minor, are reported so that the cause can be identified.
• Review new experimental procedures with students and discuss all safety concerns. Where particularly hazardous chemicals or procedures are called for, consider whether a substitution with a less hazardous material or technique can be made.
• Make sure the safety rules within the laboratory (e.g., putting on eye protection at the door) are followed by everyone in the laboratory, from advisor to undergraduate researcher, including custodial and facility staff. 
• Recognize and reward students and staff for attention to safety in the laboratory. 

3.3.5 Hazard Communication

3.3.5.1 Signs and information

Labels and warning signs should be placed in the laboratory to alert lab workers and emergency response personnel to potentially hazardous materials and allow those unfamiliar with the laboratory surroundings to identify hazardous chemical use and storage areas, safety facilities, emergency equipment, and exits.

3.3.5.2 Safety Data Sheets (SDSs)

Chemical manufacturers and distributors are required to provide Safety Data Sheet (SDS) that describes the hazards associated with the chemical and provides information for the safe handling, storage, and disposal of the chemical. An SDS has 16 standardized sections. Those concerned with chemical safety in the laboratory should give special consideration to the following sections of the SDS: Hazard identification (2); Composition (3); First aid measures (4); Accidental release measures (6); Handling and storage (7); Exposure controls/personal protection (8); and Stability and reactivity (10). Additional SDS information is provided through the University’s Hazard Communication training.

The University’s online system, MSDSonline provides access to digital copies of safety data sheets and is the recommended method for the management of SDSs. A computer must be readily available to laboratory researchers for viewing SDSs. A link for accessing MSDSonline can be found at the bottom of most Michigan Tech webpages, listed under the “Need to Know”column. The MSDSonline web address can be found on the Emergency Response Poster posted at the entrance of each laboratory that uses MSDSonline for SDS management.

The Michigan Right-to-Know law requires that SDSs are kept in a systematic and consistent manner. The location of all SDSs for hazardous chemicals used in the laboratory must be indicated by the Michigan Right-to-Know Law poster or similar.

3.4 Personal Protective Equipment (PPE)

Appropriate Personal Protective Equipment (PPE) must be provided to all employees. Employees have the responsibility of properly using such equipment. Figure 3.4 illustrates the minimum PPE required when using hazardous chemicals in a laboratory. PPE should never be used in place of engineering and administrative controls when handling hazardous chemicals. Proper PPE selection can be determined by a combination of the following: 

• Ask the laboratory supervisor about proper PPE selection. 
• Review the SOP and associated hazard assessment for the task to be performed. 
• Review Section 8 of the SDS, “Exposure Controls/Personal Protection” for each chemical(s) being used.
• Contact EHS for additional information.

3.4.1 Eye and face protection

Eye protection shall be required for everyone entering a laboratory where hazardous chemicals are used and stored. The minimum acceptable requirements are for ANSI-compliant safety spectacles with side shielding. All eye protective devices must be stamped with "Z87" by the manufacturer if they meet ANSI standards. Standard prescription eye glasses do not meet the eye protection requirements. See “Current Intelligence Bulletin 59: Contact Lens Use in a Chemical Environment” for guidance on wearing contacts in the laboratory.

Safety glasses with side shields offer protection against flying fragments, chips, particles (sand/dirt), and minor splashes. When a significant splash hazard exists, or if the chemical can cause significant eye damage, other protective eye equipment must be worn.

Safety goggles (impact goggles) offer adequate protection against flying particles. These should be worn when working with glassware under reduced or elevated pressure or with drill presses or other similar situations.

Chemical splash goggles have indirect venting for splash proof sides, which provide adequate protection against splashes.

Specialized eyewear is available for LASER, UV light, infrared light hazards.

Face shields protect the face and neck from flying particles and splashes. Always wear additional eye protection under face shields. Ultra-violet light face shields should be worn when working with UV light sources.

3.4.2 Hand protection

Appropriate hand protection must be worn when there is a potential for exposure of hands to hazardous chemicals, cuts, abrasions, punctures, or harmful temperature extremes.

Some gloves are more suitable for certain hazardous chemicals than others. When selecting appropriate gloves, it is important to evaluate the effectiveness of the glove in protecting against the specific hazardous chemical(s) that will be used in the laboratory. The SDS for the chemical and the glove manufacturer’s glove chart must be consulted to select the most appropriate glove.

The “all-purpose” disposable nitrile gloves used in many laboratories will generally provide adequate protection for incidental exposures to most hazardous chemicals but may or may not be suitable for prolonged contact with a chemical. For example, the 4 mils thick, nitrile glove (Solo Ultra 999) will provide protection for up to eight hours when working with concentrated sulfuric acid but will fail within one minute when working with acetone or toluene. Discard disposable gloves after they come into contact with a chemical and put on a new pair before continuing your work.

When handling materials or equipment with harmful temperature extremes such as liquid nitrogen or autoclaves, appropriate protection such as cryogenic gloves or heat-resistant gloves must be worn.

The sites listed below may be useful in selecting appropriate gloves for use in the laboratory. Note that the compatibility rating systems used by manufacturers vary. Make sure you understand the rating system before making a decision on the glove you will use.

Hand protection must not be worn outside of the laboratory (e.g., hallways, elevators, offices) to avoid contamination of public areas. Gloves should also be removed prior to handling anything that could likely result in cross-contamination (e.g., light switches, door knobs, elevator controls, water fountains, telephones, including cell phones, computer workstations). Disposable gloves must never be reused. Always wash hands after removing gloves. The practice of wearing gloves all day while in the laboratory should be discouraged.

3.4.3 Body protection

Protective clothing must be worn to protect the body from recognized hazards. All unprotected skin surfaces that are at risk of injury should be covered. The upper torso must be fully covered, with no bare midriffs. Full-length pants or full-length skirt must be worn at all times by all individuals that are occupying the laboratory area; shorts are not permitted.

Lab coats, coveralls, aprons, or protective suits must be worn while working on, or adjacent to, all procedures using hazardous chemicals. Laboratory coats must be appropriately sized for the individual and be fastened (snap buttons are recommended) to their full length. Laboratory coat sleeves must be of a sufficient length to prevent skin exposure while wearing gloves. Flame resistant laboratory coats, sometimes referred to as “FR lab coats,” must be worn when working with pyrophoric materials, open flames, or flammable liquids greater than 1 liter in volume. It is recommended that 100% cotton (or other non-synthetic material) clothing be worn under the lab coat during these procedures to minimize injury in the case of a fire emergency.

Laboratory coats should not be worn outside of a laboratory unless the individual is traveling directly to an adjacent laboratory work area. Laboratory coats should not be worn in common areas such as break rooms, offices, or restrooms. Each department is responsible for providing laundry services as needed to maintain the hygiene of laboratory coats. In most cases a bucket and laundry detergent should suffice for a lab coat to be cleaned within a lab. They may not be cleaned by staff members at private residences or public laundry facilities. Alternatives to laundering lab coats include routinely purchasing new lab coats to replace contaminated lab coats, or using disposable lab coats.

3.4.4 Respiratory protection

Respirators may not be used unless they are approved through the Michigan Tech EHS “Respiratory Protection Program.” This program includes a review of the process to ensure that proper equipment is selected for the job; training of all users concerning the methods for proper use and care of equipment; fitting of respirator users and medical surveillance of respirator users. Contact EHS with questions about the Respiratory Protection Program.

3.4.5 Other PPE

In addition to eye, hand and body protection some laboratories may require additional PPE. See the University Safety Manual for additional requirements for head (hard hat), foot (steel toed shoes), and hearing protection. In some special cases such as spill cleanup, working with potentially infectious materials, or clean rooms disposable over-the-shoe booties may be required.

3.4.6 Minimum PPE requirements for support staff and visitors

Support staff (e.g., custodians, maintenance workers) and visitors often enter laboratories to perform routine maintenance tasks or tour the lab. To enter the laboratory, the minimum PPE requirements include safety glasses, fully covered torsos, long pants, and closed-toe shoe. If additional PPE is required or if other unique safety requirements must be followed, it is the lab personnel’s responsibility to notify support staff and/or visitors of the additional requirements.

3.5 Safety equipment

3.5.1 Safety showers and eyewash stations

All laboratories using hazardous chemicals must have access to safety showers and eye wash stations. All lab personnel must be aware of the location and know how to properly use the safety shower and eyewash stations. Eyewash and safety showers must be located:

• 100 feet or less from the hazardous operation – for chemicals that are injurious or corrosive (pH > 2 and ≤ 4 or pH ≥ 9 and < 11.5).
• 25 feet or less from the hazardous operation – For chemicals that are considered highly corrosive (pH ≤ 2.0 or ≥ 11.5.) and for certain organic materials capable of causing severe tissue damage.
• Within 100 feet of the work area for HIV and HBV research laboratories.
• The location of the shower and/or eyewash shall be easily accessible (i.e., no obstacles, closeable doorways, or turns) and should be clearly marked and well lighted. The shower and/or eyewash shall not have a protective covering that requires removal prior to use.

If lab personnel are exposed to a hazardous chemical, they should call for assistance and proceed immediately to use the safety shower or eyewash unit (ideally, someone else in the lab that is not exposed should dial 911 and assist with the decontamination of the affected individual). The affected area should be flushed with water for at least 15 minutes or until emergency response personnel arrive and begin treatment. An exposed eye(s) should be held open to ensure an effective wash behind the lids. Contaminated clothing should be removed immediately after exposure or while under the shower. It is highly recommended that laboratories have blankets or lab coats available for modesty.

Lab personnel are responsible for the recommended weekly flushing of eyewash (NOT safety showers) stations. Michigan Tech Facilities Maintenance staff performs annual inspections of all campus safety shower and eyewash stations. This inspection evaluates the basic mechanical functionality of each station. Any deficiencies are repaired by facilities staff.

3.5.2 Fire extinguishers

All fire extinguishers should be mounted on a wall in an area free of clutter. Each fire extinguisher on campus is inspected on a monthly basis. All laboratory personnel should be familiar with the location, use, and classification of the extinguishers in their laboratory. Ensure that the fire extinguisher available in the laboratory is appropriate for the anticipated type(s) of fire that may occur.

In the event of a fire, DO NOT put yourself in danger to extinguish the fire. DO NOT attempt to extinguish a fire:

• if you have not been trained to use a fire extinguisher
• if it is larger than a small garbage bin in size
• if you cannot extinguish within 5 seconds using a fire extinguisher
• Pull the fire alarm (usually located near exits)
• Exit the building
• Call 911. The 911 phone call is answered by a dispatch service located in Negaunee, MI which dispatches emergency response services for the entire UP. You will need to provide them with specific information about your location: Houghton, MI; Michigan Tech campus; Building and room number.

If you are successful at extinguishing the fire, you must still call 911 to report the incident. It is possible, depending on the nature of the incident that flare-ups may occur.

Chapter 4