A Guideline for the
Safe Use & Handling of Mercury
And Mercury Compounds
Developed by the Office of Engineering Safety (EH&S)
The Engineering Program
Texas Engineering Experiment Station
And
The Dwight Look College of Engineering
Texas A&M University
A Guideline for the Safe Use & Handling of Mercury and Mercury Compounds
Contents
1.0 Introduction
2.0 Hazards
2.1 Toxicity and Hazards
2.2 Exposure Limits
3.0 Controls for Handling Mercury and Mercury Compounds
3.1 Project Safety Analysis (PSA)
3.2 Engineered Controls
3.3 Administrative Controls
3.3.1 Hazards Assessment
3.3.2 Training
3.3.3 Work Practices
3.3.4 Medical Surveillance
3.3.5 Label and Storage
3.3.6 Packing and Shipping
3.3.7 Mercury Spill Cleanup
3.3.8 Mercury Waste Collection and Disposal
3.3.9 First Aid
3.3.10 Exposure Monitoring
3.3.10.1 Biological Monitoring
3.3.10.2 Area Monitoring
3.3.10.3 Personal Monitoring
4.0 Responsibilities
4.1 Responsible Individual
4.2 Workers
4.3 Hazards Control
5.0 Appendices
5.1 Appendix A: Basic Terms and Definitions
5.2 Appendix B: Guidelines for Cleaning Up Elemental Mercury Spills
5.3 Appendix C: Biological Monitoring & Medical Surveillance for Mercury
5.4 Table B-1: Protective Equipment to be Used for Mercury Spill Cleanup
Safe Handling of Mercury and Mercury Compounds
1.0 Introduction
Mercury is a liquid metal that is environmentally persistent and bioaccumulates in the food chain. Mercury is
present in both organic and inorganic forms. The inorganic form can be further divided into elemental mercury
and mercuric salts. Organomercury consists of long and short alkyl and aryl compounds. Elemental mercury
evaporates at room temperature and reacts with many elements to form salts, amalgams, and organomercury
compounds (see Appendix A for basic definitions). Elemental mercury, and some mercury compounds, are
listed in state and federal regulations as hazardous wastes.
This document contains
鈥? Precautions and controls for safely handling metallic mercury and its compounds.
鈥? Specific guidance for avoiding or limiting metallic mercury spills.
鈥? Guidelines for cleaning up mercury spills.
All Engineering personnel and students who work with mercury should comply with the controls specified in
Section 3.0 of this document, to prevent adverse health effects resulting from mercury use or spills.
2.0 Hazards
2.1 Toxicity and Hazards
All forms of mercury are toxic. Mercury poisoning can result from inhalation, ingestion, and injection or
absorption through the skin. Elemental mercury poses a health hazard because it is volatile. Elemental
mercury, as a vapor, penetrates the central nervous system (CNS), where it is ionized and trapped, resulting in
its extreme toxic effects. Elemental mercury is not well absorbed by the gastrointestinal tract; therefore,
when ingested, it is only mildly toxic. Mercury metal and mercury compounds are highly hazardous if inhaled,
or if they remain on the skin for more than a short period of time. Dimethyl mercury rapidly penetrates intact
skin. Depending on the type of mercury and dose, symptoms may appear relatively quickly (acute disease) or
take a number of years to appear (chronic disease). Elemental or airborne mercury that is deposited in water
bodies becomes methylmercury, which is much more toxic. Additionally, in the ambient environment mercury
readily bioaccumulates up the food chain.
Listed below are various forms of mercury and their effects and hazards.
鈥? Mercury vapor (i.e., elemental mercury) is readily absorbed through inhalation and can
also pass through intact skin. After absorption, the blood carries elemental mercury to the central
nervous system where it is oxidized. The oxidation product produces injury. Persons heavily exposed
to elemental mercury will develop characteristic symptoms, including: worsening tremors of the
hands, shyness, insomnia, and emotional instability (e.g., the symptoms of the Mad Hatter in in
Alice
Wonderlan d鈥攁 caricature of hat makers who originally cured felt in pools of mercury.) Mercury vapors
can reach very high levels when the liquid is heated. Such levels will cause adverse effects in humans
almost immediately if workplace controls are inadequate. Research apparatus and other laboratory
equipment such as thermometers, vacuum pumps, manometers, and sphygmomanometers, may
contain mercury.
鈥? Mercury salts (e.g., mercuric nitrate) are highly toxic and corrosive. They accumulate mostly in
the kidney, causing renal damage.
鈥? Organomercury compounds attack the central nervous system causing tremors, impaired
vision and hearing, and paralysis. These compounds may also cause birth defects. The effects from
exposure to excessive levels of airborne mercury or skin contact with mercury compounds may not
be noticeable for months or years.
鈥? Mercury fulminate, Hg(ONC)2, is a detonator used in explosives.
鈥? Mercury(II) oxide is an oxidizer. It can cause organic materials to start burning in the same
manner as any strong oxidizer.
鈥? Dimethyl mercury, an extremely toxic material, is a colorless, sweet-smelling liquid. It is a
severe fire hazard, with a flash point of 鈥?4掳C. This material rapidly penetrates the skin resulting in
severe to fatal exposure from very minor quantities. Extreme caution is required when working with
this material and when selecting personal protective equipment (PPE). Contact the vendor, supplier
and/or manufacturer for a current material safety data sheet (MSDS).
2.2 Exposure Limits
A worker's exposure to mercury should be less than the Threshold Limit Values (TLV鈥檚), the exposure limits
established by the American Conference of Governmental Industrial Hygienists (ACGIH.) Following are the
maximum exposures permitted for an 8-hour, time-weighted average (TWA) concentration:
Substance Threshold Limit Value (TLV)
Mercury metal vapor 0.025 mg/m 3
Mercury salts 0.025 mg/m 3
Aromatic organic compounds 0.1 mg/m 3
Alkyl compounds 0.01 mg/m 3 ( Ceiling limit is 0.03 mg/m 3 )
3.0 Controls for Handling Mercury and Mercury Compounds
Planning and documentation are required for all Engineering operations, research and teaching, which involve
the use of mercury. This section contains controls for preventing unnecessary exposure and minimizing the
likelihood and extent of mercury spills. Guidelines for cleaning up a mercury spill can be found in Appendix B.
3.1 Project Safety Analysis
Project Safety Analysis (PSA) is a procedure to increase the knowledge of hazards in a project or operation, by
identifying the potential for loss and risk early in the project planning process. The Engineering Safety Policy
(established February 1996) requires Project Safety Analysis for all new projects, and for on going projects
where potentially harmful or dangerous conditions present an unacceptable risk. The PSA defines the
proposed project; the facilities, apparatus, equipment and chemicals to be used; the hazards and risks of each
stage of the project; the necessary controls for preventing potential harmful exposures and/or releases;
standardized safe work practices and procedures; the ultimate disposition of apparatus, equipment, materials
and chemicals; and clean up and decontamination of facilities. The faculty/PI responsible for the individual
project or operation is required to initiate a PSA to the Office of Engineering Safety for evaluation.
3.2 Engineered Controls
The following controls should be available for activities involving the use of mercury:
鈥? Adequate ventilation or vapor-containment systems.
鈥? Mercury Spill-Control Kits. These should be in all work areas where >1.0 ml of mercury is used
(except for small sealed items, such as thermometers and sphygmomanometers). Spill control kits
should be replaced or restocked following each use. Employees shall contain and control spills, and
summon the TAMU Hazardous Materials Emergency Response Team for clean up and disposal (From a
TAMU telephone, dial 9-9-1-1, for emergency response assistance).
鈥? Catch basins and pans made of smooth impervious material (e.g., plastic or smooth-finish paint)
and with edge lips. Note: Steep edge lips are more effective than gentle rises in trapping spilled
mercury.
Catch basins should be large enough to contain the greatest amount of mercury that could
spill, and be positioned to catch mercury droplets escaping from any plausible direction. (It
may be useful to place absorptive mats on seamless plastic sheets in or under catch pans to
capture mercury leaks from the equipment. Droplets of mercury can then be collected by
simply wrapping up the plastic with the mat still inside and disposing of it as mercury
waste.) Section 3.2.8 contains more information on the disposition of hazardous materials.
鈥? Removable plastic shields, mercury traps, and blowout valves.
鈥? Concrete floors should be sealed with epoxy. Impervious working surfaces with few crevices are
preferred for work involving mercury. Carpeted and tiled areas shall not be used.
3.3 Administrative Controls
The administrative controls listed in this section should be implemented when mercury and its compounds are
involved in operations.
3.3.1 Hazards Assessment
Before beginning any Engineering project or operation involving the use of metallic mercury, mercury
compounds, mercury apparatus or equipment containing mercury, the Responsible Faculty/PI should:
鈥? Prepare an Integration Work Sheet (IWS) for the operation. Become familiar with the hazards
associated with the materials for the particular operation and implement all necessary controls. The
current MSDS must be obtained for each hazardous material, including mercury and mercury
compounds, describing its hazards and controls.
鈥? Determine if the worker's current training is adequate for the activity. All affected personnel shall
complete training in Laboratory Safety, Hazard Communication, operation of specific apparatus and
equipment, and safe work practices and procedures. All training shall be documented and records
maintained as specified in the TAMU Hazard Communication Program, the TAMU Safety Manual, and
the Engineering Safety Policy.
鈥? Notify the Office of Engineering Safety and the TAMU Environmental Health & Safety Department
(EHSD) of each new use of mercury, except for sealed items such as thermometers. A Project Safety
Analysis (PSA) is required for all new projects and for on-going projects when significant changes
occur or when hazardous conditions warrant.
The Office of Engineering Safety Office should:
鈥? Provide guidance on the selection of controls and job-specific training.
鈥? Determine the required workplace monitoring for mercury, as needed.
鈥? Determine if a written safety plan is necessary for operations that involve heating or using large
quantities of mercury or its compounds. The Safety Office may waive the requirement for a written
safety plan, if the quantity is small (so that one/half of the vapor limits in Section 2.2 are not
exceeded) or for totally enclosed systems using quantities >1.0 ml. NOTE: An Operational
Safety Plan (OSP) is ALWAYS required when using dimethyl mercury.
TAMU-EHSD should:
鈥? Evaluate the operation(s) to determine if air permits are required and/or the appropriate TNRCC
and/or EPA documentation has been prepared and approved.
3.3.2 Training
Employees and students who potentially may be exposed to mercury should be trained in the hazards and
controls before initial assignment, as described in the TAMU Hazard Communication Program. The required
training should include at least the following areas:
鈥? Safe use of mercury.
鈥? Mercury hazards.
鈥? Cleanup of small spills. (Appendix B discusses mercury cleanup guidelines.)
鈥? Proper use of mercury vacuum cleaners. Workers who use breakable or open equipment containing
>1.0 ml of metallic mercury shall receive training in the proper use of mercury vacuum cleaners and
other spill cleanup procedures.
鈥? Use of PPE, including respirator training.
鈥? Procedures for summoning emergency response services, and for incident notification/reporting.
鈥? Hazard Communication, Laboratory Safety, Prudent Laboratory Practice, PPE
鈥? Site, project and/or laboratory specific safe work practices and procedures
Training in basic laboratory safety and chemical hazard communication is provided without charge by TAMU.
Registration information is available at:
Laboratory Safety Training
http://ehsd-online.tamu.edu/training/lab.htm
Hazard Communication Training
http://ehsd-online.tamu.edu/training/hazcom.htm
3.3.3 Work Practices
Mercury users should be aware of and follow work practices listed below:
Dimethyl mercury. This chemical is so toxic that its use always requires OSP. Additionally, inner (silver
an
shield, 4H, or other brand laminate-style gloves) and outer gloves (heavy-duty nitrile or neoprene, with long
cuffs) are required as a minimum when handling, using, or working with dimethyl mercury.
3.3.3.1 For all forms of mercury, the following work practices apply:
鈥? Avoid using mercury whenever possible. Use alternative equipment and/or instruments that have
no mercury to measure temperature or pressure. Where alternative materials or methods are
available, prudent laboratory practice requires choosing the less hazardous alternative.
鈥? Depending on the type and concentration of mercury involved and the work to be done, additional
PPE may be required, above the minimum. Contact the Office of Engineering Safety or the TAMU-
EHSD industrial hygienist for assistance.
鈥? Do not eat, drink, or smoke; or store food, drinks, smoking materials, or cosmetics in any area
where mercury is in use.
鈥? Avoid skin and eye contact. Use appropriate protective gloves when handling metallic mercury.
DO
NOT use lightweight disposable gloves for heavier jobs, as these can tear easily and allow mercury to
lodge under the fingernails or contact other parts of the skin. When the operation may result in
exposure to the face, wear splash-proof goggles a face shield, unless full-face respiratory
AND
protection is being used.Note: Quantitative permeation or penetration information is scarce on the
type of gloves or protective clothing that offer protection from exposure to mercury compounds.
鈥? Wash hands and face after handling mercury, before lunch or breaks, and at the end of each work
period.
鈥? Do not work with mercury on surfaces with cracks (e.g., tile seams, spaces between wood boards,
baseboards, wall coving, gaps between table legs and floors), crevices, and hard-to-reach spaces;
porous surfaces (e.g., carpets, wood, and crinkle-texture paint), and false floors.
鈥? Do not store or handle mercury near sinks or drains. Spilled mercury could run into the sink, lodge
in the trap, ruin the pipe by amalgamating with and weakening the metal, and then be released into
the environment or a retention tank system designed only for dilute solutions in rinse water. Mercury
in the plumbing and drains may result in unnecessary and potentially adverse exposure to
maintenance workers and others.
鈥? Avoid using mercury or mercury compounds in operations that could generate mercury waste
streams contaminated with radionuclides, as it is expensive and often impossible to dispose of this
type of mixed waste stream. Where the project necessitates the generation of a mercury waste
stream with radionuclides, the responsible Faculty/PI is required to document appropriate
arrangements for proper waste disposal or long-term storage of the waste, as a component of the
PSA.
鈥? Transfer of liquid mercury between containers should be carried out in a fume hood over a tray or
pan to confine any spills.
鈥? Conduct weekly self-inspections of all PPE, controls, equipment, and apparatus. Inspection findings
and corrective action(s) should be documented.
3.3.4 Medical Surveillance
An occupational medicine physician should determine the need for biological monitoring or medical surveillance
examinations of workers with potential mercury exposure. The requisite biological monitoring or medical
surveillance examinations should be determined based on an evaluation of the operation, workplace controls,
and relevant human factors as well as input received from the Faculty/PI, affected workers, and safety officers.
At a minimum, all affected persons should be monitored for mercury in blood and urine BEFORE working with
mercury to establish a baseline for evaluation, and at least every three months for project duration. (Refer to
Appendix C for additional information on biological monitoring and medical surveillance).
3.3.5 Labeling and Storage
The following controls apply to the labeling and storage of mercury and its compounds:
鈥? Label all containers of metallic mercury and its compounds.
鈥? Label all mercury containers and storage as follows:
WARNING: CONTAINS MERCURY
VAPOR HARMFUL AT ROOM TEMPERTURE
MAY BE FATAL IF HEATED IN THE OPEN
DO NOT BREATHE VAPOR
USE WITH ADEQUATE VENTILATION
AVOID SKIN CONTACT
鈥? Do not store mercury near chemicals that can create explosive mixtures with mercury (e.g.,
acetylene, ammonia, boron phosphodiiodide, chlorine dioxide, methyl azide, ground sodium carbide,
and others鈥?) or with radioactive materials. Keep mercury compounds that are oxidizers separate
from organic materials and other combustibles. Additionally, all chemical storage is required to be
segregated by Hazard Class.
鈥? Minimize the amount of mercury in use or in storage. Mercury storage should have inherent spill
containment/control.
鈥? Store mercury in a cool, separate and secure location.
鈥? Use containers made of impact-resistant material, or place them in sturdy secondary containers.
鈥? Keep all mercury containers tightly closed when not in use. Avoid cutting cartons that contain
plastic bottles filled with mercury. A plastic bottle could be cut or torn open and result in a mercury
spill.
3.3.6 Packing and Shipping
Use appropriate packing materials for mercury containers, such as Kimpak bubble pack, for all mercury
TM, or
containers and objects/devices containing mercury.
3.3.7 Mercury Spill Cleanup
Elemental mercury is typically easy to work with under normal conditions (e.g., in a fume hood). However, spills
involving elemental mercury that are ignored or improperly addressed can cause serious problems because:
鈥? Mercury is dense (specific gravity ~13.5). Large drops shatter into numerous small droplets that
can move at great speed across long distances.
鈥? Droplets and vapors tend to congregate in crevices. Porous materials can become contaminated
and may have to be disposed of as mercury waste (see Section 3.2.8) because they are too difficult
to decontaminate.
鈥? Mercury amalgamates with other metals. Metal objects are weaker after contamination with
mercury, and may be unsuitable for further use. Items soiled by spilled mercury often cannot be
decontaminated and, therefore, should be disposed of as mercury contaminated hazardous waste
(see Section 3.2.8).
鈥? Microorganisms convert metallic mercury to organomercury compounds, which are more hazardous
in some species than the metallic form. This may result in significant environmental problems,
particularly when mercury enters into the aquatic food chain.
鈥? Mercury will bioaccumulate in the environment and, thus, be passed up the food chain.
If a mercury spill occurs, immediately:
1. Block off any area where droplets of spilled mercury are visible using tape or rope, and post signs
(such as example below) made of any available material.
MERCURY SPILL 鈥? Keep Out!
2. Avoid walking on or touching any surface contaminated with mercury.
3. Promptly notify the TAMU Hazardous Materials Emergency Response Team at 845-2132, or dial 9-
9-1-1 to summon TAMU emergency services. The HazMat Team will survey the affected area to
determine the airborne concentration of mercury, adjust the boundaries of the blocked-off area as
needed, conduct cleanup and disposal of spilled mercury, and provide technical support. Costs of
emergency response, cleanup and waste disposal may be billed to the responsible Faculty/PI,
laboratory, department or TEES research center.
4. Notify the Office of Engineering Safety.
5. Personal protective equipment (PPE) and clothing specifically designed for use with mercury must
be readily available for unusual situations and for spill cleanup. If a mercury spill is too large to clean
up safely or workers are injured or contaminated, dial 9-9-1-1, to summon TAMU emergency response
and medical services.
6. Small spills of metallic mercury may be cleaned up safely by the personnel involved if they have
had the proper training and equipment.
7. Mercury Spill Kits must be available in each work area where mercury is present. Use of vacuum
cleaners/shop vacuums for mercury spills is prohibited. Use only specially designed and dedicated
mercury vacuum cleaners. Guidance for cleaning up mercury spills is in Appendix B.
3.3.8 Mercury Waste Collection and Disposal
Generators of mercury-contaminated wastes should evaluate the waste to determine if any applicable
hazardous-waste criteria have been exceeded. All generators must be in compliance with TAMU rules and
other applicable regulations.
Equipment or objects containing mercury, but no longer needed by a program, should be
evaluated in accordance with the TAMU Hazardous Waste Management Program. Equipment or objects
characterized as hazardous waste should be tagged and prepared for transport and disposal through the
TAMU-EHSD Hazardous Waste Management Program.
The responsible Faculty/PI should document a plan for the ultimate disposition of hazardous materials &
hazardous waste, and the clean up & decontamination of apparatus, equipment and facilities. The disposition
plan should be finalized before purchasing materials or initiating project activity.
3.3.9 First Aid
Personnel contaminated with dimethyl mercury should immediately:
1. Wash the affected area using either an eyewash station or safety shower, as appropriate.
2. Report to TAMU Emergency Medical Services (dial 9-9-1-1). Be sure to inform the medical
responders or physicians of the quantity of mercury involved.
Personnel contaminated with mercury metal or other mercury compounds should exercise the following
precautions:
1. Immediately wash the affected area using either an eyewash station or safety shower, as appropriate.
2. Report to TAMU Emergency Medical Services (dial 9-9-1-1). Be sure to inform the medical
responders or physicians of the type, quantity, and physical state of mercury involved.
3. Use a mercury vapor monitor to make sure there is no mercury on the skin or in the space under the
fingernails. If necessary, clean the area with soap, water, and a scrub brush; then, recheck with the
instrument to ensure that all of the mercury is removed not use the solutions that come with
. Do
mercury cleanup sponges or powders for PERSONAL decontamination 鈥? some are corrosive!
4. Remove and place all contaminated clothing in a plastic bag. Personnel who are not contaminated
should handle spill cleanup only if they are trained and equipped. Immediately notify TAMU-EHSD if
any cleaning water is discharged into a sink, drain, retention tank, or sanitary sewer system.
4.0 Responsibilities
General responsibilities for all faculty, staff and students, are described in the 鈥淓ngineering Safety Policy.鈥?
4.1 Responsible Individual
The responsible faculty/PI, department head, or designee, should ensure that all persons who might handle
mercury are trained in accordance with the provisions of this document and the TAMU Hazard Communication
Program (HazCom), prudent laboratory practice, and established project-specific procedures.
4.2 Personnel
All faculty/PI, staff, students and other affected persons should:
鈥? Follow the precautions for mercury specified in this document, in the Engineering Safety Policy, and
in procedures cited or included as part of the TAMU Safety Manual and the TAMU Hazard
Communication Program.
鈥? Additional guidance on the safe handling and disposition of mercury is available from the Office of
Engineering Safety and from TAMU-EHSD.
4.3 Hazards Control
The responsible faculty/PI, department head, or designee should:
鈥? Provide support and training to anyone who handles mercury or cleans up mercury spills.
鈥? Provide appropriate controls, personal protective equipment (PPE) and protective clothing.
鈥? Provide mercury spill kits and other equipment as necessary to safely contain and collect spilled
mercury. Ensure that mercury vacuum cleaners are maintained in good working condition.
鈥? Provide the appropriate respiratory protection and training to all affected persons.
鈥? Ensure that all mercury is properly stored and secured.
鈥? Ensure that all apparatus, equipment and facilities are cleaned and decontaminated at project
closure.
鈥? Ensure that all small, sealed mercury-containing items (such as thermometers) are securely stored.
Non-mercury alternatives are recommended as prudent practice, to reduce risk of spill and exposure.
5.0 Appendices
5.1 Appendix A: Basic Terms and Definitions
Absorption - method whereby a substance can pass through intact, unbroken skin.
Amalgam - mixture or alloy of mercury with other metals.
Catch pan/basin - a secondary container used to collect minor spills.
Central Nervous System (CNS) - Parts of the nervous system, including the brain
and spinal cord.
Manometer - An instrument used to measure gas and vapor pressure.
Mercury salts - Inorganic mercury compounds.
Mercury vacuum - specially designed type of vacuum cleaner used to safely collect spilled mercury.
Metallic mercury - Mercury in its elemental state.
Organomercury compounds - Mercury compounds that include carbon atoms, bonding directly to the
mercury atom.
Sphygmomanometer - An instrument used for monitoring blood pressure.
5.2 Appendix B: Guidelines for Cleaning Up Elemental Mercury Spills
Respond promptly to all spills and accidents involving any hazardous chemical. Contact the TAMU Hazardous
Materials Emergency Response (dial 9-9-1-1 or 845-2132) for assistance in cleaning up a chemical spill.
A small spill is a release that meets ALL of the following criteria:
鈥? Nature and potential hazard of material is known.
鈥? The incident results in no injury to people or damage to facilities.
鈥? Release presents no actual or potential threat to human health, the environment, or property.
Any spill that exceeds any of the above criteria is considered a large spill. For large spills, immediately
call 9-9-1-1 to summon emergency response services.
The following guidelines apply when cleaning up mercury spills:
鈥? Use sufficient PPE and protective clothing (see Table B-1) to keep mercury droplets off personal
clothing and skin. This includes plastic or rubber gloves, disposable foot covers (whenever mercury is
on the floor), and additional protective clothing when in doubt of the proper clothing to use. All
protective equipment and clothing shall be rated for use with mercury.
Never use thin disposable
gloves, as these can tear and allow mercury to lodge under the fingernails.
鈥? Use the buddy system when respirators are required. Watch the color of the end-of-service
indicators on the faces of the other people's cartridges, and have them replaced when the indicators
change color. Use only respirator cartridges rated for mercury use. Be careful not to drag airline
respirator hoses through mercury. Check the hoses and equipment with a mercury vapor monitor for
contamination before storing.
鈥? Spread plastic sheets over surfaces onto which mercury could drop or run during spill cleanup.
Tape the sides of the sheets to the floor. NOTE: such plastic sheets, and other clean up items, must
be disposed of as mercury contaminated hazardous waste.
鈥? Remove any dust or oil which may have become contaminated with mercury during spill and
cleanup. Use detergent or a solvent to remove oil or grime, or use a vacuum, to remove dust. Be
certain to adhere to all appropriate controls during spill cleanup.
鈥? Dip rags in cleaning solutions once. Never dip a dirty rag in a clean solution, as this will contaminate
the solution and the container. Minimize the amount of mercury-contaminated material generated
during cleanup, as it is expensive to dispose of mercury contaminated liquid wastes. Clean up
materials must be contained and disposed of as hazardous waste.
鈥? Use mercury kits with hand-powered miniature vacuums or sponges to clean up spills whenever
practical. Replace mercury kit items after use.
鈥? To avoid the spread of contamination, never sweep mercury contaminated material or blow it off of
surfaces with compressed-air nozzles. Instead, vacuum or seal it off in place.
鈥? Trapped mercury inside equipment, instruments and building components can be a health hazard to
those who work on affected surfaces in the future. A sign indicating that trapped or sealed mercury
is present may be needed. Avoid trapping or sealing any mercury in place. Clean and decontaminate
all apparatus, equipment and facilities following use, or dispose of as hazardous waste. Notify TAMU-
EHSD of any suspected trapped mercury.
鈥? Use a specially designed and dedicated vacuum for cleaning up large mercury spills. Check the
vacuum's exhaust with a mercury vapor monitor before using it and remove as much mercury as
possible from inside the vacuum after using it鈥攖oo much residual mercury can ruin the mercury
absorber. Do not use a regular or HEPA vacuum cleaner to clean up mercury spills because mercury
amalgamates with copper in the motor, and the vacuum will exhaust high concentrations of mercury
vapor into the air. The vacuum then becomes dangerous to use or decontaminate and ultimately
must be disposed of as hazardous waste.
鈥? Use 鈥淩esisorb鈥? to eliminate mercury vapors near surfaces, particularly after removing liquid mercury
from those surfaces.
鈥? Contact TAMU-EHSD for assistance in cleanup operations and/or to determine the appropriate
packaging requirements for bulky items that may be contaminated with mercury.
鈥? Place used rags, cleaning materials, protective gear, and mercury-contaminated gear into plastic
bags. Cut up mops and other large tools before placing them into the bags. Gently squeeze excess
air from the bags, then place the sealed bags into drums and affix a completely filled out TAMU
Hazardous Waste Tag to the drum. Contact TAMU-EHSD or the Office of Engineering Safety for
training and/or assistance in completing the Waste Tag form. TAMU-EHSD will transfer the drum to
the designated Waste Accumulation Area.
鈥? Have the Hazardous Materials Emergency Response Team conduct a clearance survey before
removing any access barriers. The spill area shall not be returned to normal use until this survey is
completed.
鈥? Notify TAMU-EHSD if mercury-contaminated water enters into a drain, retention tank or sanitary
sewer, so that appropriate action can be initiated.
5.3 Appendix C: Biological Monitoring & Medical Surveillance for Mercury
5.3.1. All affected personnel, faculty/PI and students, should be tested by approved biological monitoring
procedures prior to starting work on any project using significant amounts of mercury, to establish a baseline
for future comparison. All personnel should be tested periodically over the course of the project, and results
compared to the established baseline to determine if potentially harmful exposure has occurred. An
occupational medicine physician should determine frequency of the periodic tests.
5.3.2. BIOLOGICAL MONITORING FOR MERCURY
Total Inorganic Mercury in Urine
Monitor pre-shift
BIE = 35 micrograms per gram creatinine
Total Inorganic Mercury in Blood
BIE =15 micrograms per gram
NOTE: Mercury may be present in biological specimens collected from subjects who have not been
occupationally exposed, at a concentration that could affect interpretation of the result. Such background
concentrations are incorporated into the BEI value.
Biological monitoring provides one means to assess exposure had health risk to workers. It entails
measurement of the concentration of a chemical determinant in the blood, fluids and tissues of those with
potential exposure; it is an indicator of the uptake of a substance. Biological monitoring indirectly reflects the
dose to a worker from exposure to the substance of interest. In most cases, the specimen used for biological
monitoring is urine, blood, or exhaled air.
Biological Exposure Indices (BEI) are values for assessing biological monitoring results. BEI's represent the
levels of determinants which are most likely to be observed in specimens collected from healthy workers who
have been exposed to potentially harmful substances to the same extent as workers with inhalation exposure
at the Threshold Limit Value (TLV). The BEI indicates a concentration below which nearly all workers should
not experience adverse health effects. The BEI determinant can be the chemical itself, one or more
metabolites, or a characteristic, biochemical change induced by the chemical. BEI's are not intended for use as
a measure of adverse effects or for diagnosis of occupational illness.
Biological monitoring provides assistance to the occupational health professional and/or physician to:
1. detect and determine absorption via the skin or gastrointestinal system, or via inhalation
2. assess body burden
3. determine PAST exposure(s)
4. detect occupational and/or non-occupational exposures among workers
5. test the efficiency of engineering controls and PPE
6. monitor work practices
BEI鈥檚 are intended as guidelines to be used in the evaluation of potential health hazards. BEI鈥檚 apply to 8-hour
exposures, 5 days per week. Although modified work schedules are sometimes used in various occupations,
the ACGIH BEI committee does not recommend that any adjustment or correction factor be applied to the
BEI'鈥?, i.e., the BEI'鈥? should be used as listed, regardless of the work schedule.
The Threshold Limit Value (TLV) for inorganic mercury is 0.025 mg/g of air. The primary route of exposure is
cutaneous; either by contact with vapors or, more likely, by direct contact with the skin.
5.3.3. SOURCE OF BIOLOGICAL MONITORING CRITERIA
The detailed scientific criteria and justification for each BEI can be found in the
Documentation of the
Threshold Limit Values and Biological Exposure Indices , published annually by the American Association of
Governmental Industrial Hygienists (ACGIH).
Appendix 5.4. Table B-1: Protective Equipment to be Used for Mercury Spill Cleanup
Item Description
Impervious gloves Left and right hand;
Sizes: medium and large
Shoe covers, disposable Standard
Booties, heavy soled Standard
Apron, laboratory heavy-duty
Apron, laboratory light-duty
Disposable coveralls without hood (Sizes: small, medium, and large)
Disposable coveralls with hood (Sizes: small, medium, and large)
Respirator, cartridge a
Respirator, airline a, b
NOTES:
a- Use of this respirator shall be approved in advance
by an industrial hygienist. Respirators shall be issued
only to persons who are trained in its use, medically
qualified, and who have no facial hair that will
interfere the respirator's effectiveness.
b- Airline hoses and equipment shall be monitored for
mercury contamination before they are returned to
the approved storage location.
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