CPL 2-2.6 OSHA Instruction October 30, 1978
OSHA PROGRAM DIRECTIVE #300-2
TO: Field and National Offices/OSH
SUBJECT: Inorganic Mercury and Its Compounds
1. PURPOSE
This directive provides guidelines to be followed in inspection, and
where necessary, the issuance of citations, regarding exposure to mercury in
the workplace.
2. DOCUMENTATION AFFECTED
None
3. DOCUMENTATION REFERENCED
a. Field Operations Manual, Chapter XIII. b. OSHA Standard
Methods for Sampling Total Dust, Metal Fumes, and Liquid Aerosols.
c. Guidelines for Controlling Occupational Exposure to Mercury or
its Inorganic Compounds.
4. BACKGROUND
a. Chemical Data. On the following page is a table of properties
of some commonly encountered mercury compounds. A vapor pressure curve for
mercury follows the table.
b. Fire, Explosion Potential, and Reactivity. Although elemental
mercury presents little danger of fire or explosion, several mercurial
compounds do pose such a threat. Some organic mercurial compounds (e.g.
mercury fulminate) pose a serious threat, however, they are not the concern
of this directive. Among the inorganic mercurial compounds, several are
reported as being physical hazards. Mercury nitride poses an explosion hazard
when exposed to heat. Upon contact with acids or moisture, mercuric selenide
readily liberates flammable gas. Mercurous chromate, mercurous chloride,
mercurous oxide, and mercury ore (cinnabar) are also reported to be flammable
under certain conditions and potential physical hazards.
c. Other relevant Information. This section is for information
purposes only, not for compliance action.
(1) Common Processes. A brief description of the common
processes involved in the production, use, and handling or mercury and its
inorganic compounds is impossible due to its numerous industrial
applications. There are over 600 major industrial plants currently using
mercury in its elemental form. Listed below are several broad industrial
areas in which mercury is used.
PROPERTIES OF SOME MERCURY COMPOUNDS
Vapor Melting Pt. Boiling Pt. Compound Appearance Pressure
C C
--------------------------------------------------------------------- Mercury
Silver-White 1mm Hg -38.87 deg 356.58 deg (elemental) heavy,
mobile, at 126.2 C Hg liquid metal
--------------------------------------------------------------------- Mercury
Ore Bright scarlet- Sublimes (Cinnabar, red powder or
at 583.5 deg Mercuric lumps; blackens Sulfide) on exposure to Hgs
light
---------------------------------------------------------------------
Mercuric White powder 1 mm Hg 277 deg. 302 Chloride or
crystals at 136.2C HgCl2
---------------------------------------------------------------------
Mercurous White crystals, Sublimes Chloride or crystalline
at 400 deg. HgCl2 powder; taste-
less, odorless
_____________________________________________________________________
Mercurous Black to Decomposes Oxide
grayish-black at 100 deg C Hg20 powder
--------------------------------------------------------------------- Mercury
Brown powder Explodes Nitride Hg2N2
---------------------------------------------------------------------
Mercurous Red needles Decomposes Chromate or powder
Hg2Cr04 ---------------------------------------------------------------------
Mercuric Gray plates Sublimes Selenide HgSe
--------------------------------------------------------------------- - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Continued From Above
--------------------
Mol. Solubility Flammability
Compound Weight In H20
--------------------------------------------------------------------- Mercury
200.59 Insoluble (elemental) Hg
--------------------------------------------------------------------- Mercury
Ore 232.68 10 mg/1 When ignited in (Cinnabar, at
18 C air, decomposes Mercuric to
metal and sulfur Sulfide) which burns to
S02. HgS
---------------------------------------------------------------------
Mercuric 271.52 1 gm/13.5 ml Chloride HgCl2
---------------------------------------------------------------------
Mercurous 472.14 Practically Chloride Insoluble
Hg2Cl2 ---------------------------------------------------------------------
Mercurous 417.22 Insoluble Moderate Oxide Hg20
--------------------------------------------------------------------- Mercury
629.85 Severe explosion Nitride
hazard when Hg2N2 exposed
to heat.
---------------------------------------------------------------------
Mercurous 517.23 Moderate, by Chromate
chemical reaction; Hg2Cr04
an oxidizer
---------------------------------------------------------------------
Mercuric 279.57 Readily liberates Selenide
flammable gas upon HgSe
contact with acids or moisture
---------------------------------------------------------------------
For Graph entitled "Elemental Mercury Vapor Pressures at Various
Temperatures", see printed copy.
(a) Mechanical. Because mercury is a liquid at low
temperatures with no tendency to wet glass, it is widely used in scientific
instruments such as thermometers and barometers. Mercury is also used in the
pressure gauges of vacuum pumps. Potential mercury exposure is a problem not
only in the production of such instruments, but also in research institutions
where such instruments are used extensively.
(b) Electrical. Mercury's very high level of electrical
conductivity lends itself to use in electrical appliances. The principal use
of mercury in this category is for batteries. Mercury is also used in
rectifiers, oscillators, power control switches, and vapor
lamps.
Mercuric oxide is used extensively in dry cells. In
such a battery, the depolarizer is composed of mercuric oxide, the
electrolyte is a strongly alkaline solution of potassium hydroxide saturated
with potassium zincate, and the anode is of zinc. In the manufacture of
these cells, processes such as mixing, blending, and tableting of the mercury
present potential exposure problems. The exposure may be to mercury dust or
vapor.
(c) Chlorine. The chlor alkali process uses saturated and
heated salt brine (25% NaCl in water) to produce Cl2 (chlorine gas), H2
(hydrogen); and NaOH (sodium hydroxide) by electrolysis. The two basic cell
types are diaphragm cells and the mercury cells. Several different designs
in each cell type can be found. Low-voltage, high-amperage power is used in
both types. The cells are usually hooked up in series. Diaphragm cell
construction materials include asbestos, lead, concrete, stoneware, and
possibly fiberglass. Diaphragm cells do not contain mercury. The mercury
cell uses mercury in a two-chamber system; in the first (electrolyzing)
chamber, chlorine gas is produced and the sodium ion is amalgamated in the
mercury. In the second (denuding) chamber, hydrogen is formed when the
amalgam contacts water and the sodium ions combine with the remaining
hydroxyl ion (OH-) to form NaOH. The basic process reaction for the
electrolytic cells is
Na+ + Cl- + H+ + OH- -----
Na+ + 1/2Cl2 + 1/2H2 + OH-
In this process the NaOH is extremely corrosive and
mercury leaks, spillage, and recovery are always a problem. As the cells age
and become inefficient, they have to be rebuilt. Rebuilding is a routine
operation in chlor alkali plants, where cells are operated in batteries of
tens and even hundreds. During the rebuilding process, the cells are leveled
off, exposing the mercury surface, creating a potential exposure
problem.
(d) Paint. In the paint industry, mercury is commonly used
in its organic form. In the primary paint industry, however, mercury may
initially be in its elemental form, even though the final product may be
organic. In such primary manufacture, there may be some potential mercury
exposure.
OSHA Instruction CPL 2-2.6 CH-1 June 3, 1985 Office of Health Compliance
Assistance
(e) Medicinals. Mercury is used primarily in dental supply
and equipment. Dentists have a variety of uses for mercury, the primary one
being a filler for cavities. Due to mercury's use in medical equipment and
supplies, dental schools and offices and hospitals are sites of potential
exposure.
(2) Signs and Symptoms of Intoxication. Intoxication may occur
in workers excessively exposed to mercury or to its compounds. The exposure
may be due to mercury vapor, mist, dust, or fume, by inhalation, ingestion,
or through skin.
Two general types of mercury intoxication exist,
chronic and acute. Chronic mercury intoxication is caused
by exposure to a low concentration of mercury over an extended period of
time. Acute mercury intoxication is due to a greater exposure and is
unrelated to time factors. Definite symptoms of chronic mercurialism may not
appear until after six months of exposure, or longer. The symptoms are
primarily of the nervous and digestive systems.
The symptoms of overexposure to mercury may
include such personality manifestations as:
irritability, excitability, or excessive timidness. Other
symptoms include: headaches, drowsiness or insomnia, and weakness. Many
cases also include reports of sore mouths, excessive salivation, and
perspiration. In mercury intoxication, a common symptom is a tremor which is
aggravated by emotion or excitement. Also included in the literature as
symptoms of mercury intoxication are: loss of appetite, weakness, digestive
disorders, kidney damage, and bleeding gums.
If an inspector is unfamiliar with biological
monitoring methods used for mercury, he or she should check
with his Senior Industrial Hygienist. When evaluating biological symptoms,
trends within groups of employees should be noted. Elevation in mercury
levels within a group is often a more significant finding than elevations in
an individual because it indicates a common source.
PARAGRAPH DELETED
This page replaces deleted pages 6-14.
CPL 2-2.6 OSHA Instruction October 30, 1978
Dear Sir:
The nature of work at your establishment indicates to the Occupational
Safety and Health Administration (OSHA) that mercury in various forms may be
used in your manufacturing process. As you know, the present permissible
exposure limit to mercury is 1 mg/10 M3 (.1 mg/M3) expressed as a
time-weighted average concentration for an 8-hour period. In order to
achieve compliance with this mandatory airborne mercury level, you must
implement feasible engineering or administrative controls or maintain an
effective respiratory protection program should such controls be found
infeasible. The National Institute of Occupational Safety and Health has
recommended that the permissible exposure limit for mercury be lowered to .05
mg/M3. This recommendation is currently being considered by OSHA.
As an interim measure until such time as a complete standard is promulgated
we are forwarding herewith recommended guidelines for protection of your
employees against the risk of illness resulting from exposure to inorganic
mercury and its compounds. These recommendations involve preventive steps of
good housekeeping, personal hygiene, medical surveillance, monitoring and
measuring of exposure levels, employee training, and respirator information
which should ensure a healthful workplace for those of your employees who are
involved in such manufacturing processes. The issuance of these guidelines
does not alter our intention to continue our compliance activities.
The threat of mercury poisoning is ever present if mercury and its compounds
are not treated with utmost care in the manufacturing process. Therefore,
voluntary compliance with the enclosed nonmandatory guidelines would further
the overall objective of the Occupational Safety and Health Act - to assure
so far as possible, safe and healthful working conditions.
Your cooperation in this matter is greatly appreciated. Protection of your
employees from overexposure to mercury is, I am confident, our common goal.
Bert M. Concklin Deputy Assistant Secretary
Guidelines for Controlling Occupational Exposure to Mercury
or Its Inorganic Compounds
In accordance with the Occupational Safety and Health Administration's
(OSHA) standard for air contaminants (29 CFR 1910.1000), employee exposure to
airborne mercury or its inorganic compounds shall not exceed an 8-hour
time-weighted average limit of 1 mg/10 M3 (0.1 mg/M3) or a limit set by a
state agency whenever a state-administered Occupational Safety and Health
Plan is in effect. It should be emphasized that the permissible exposure
limit is a time-weighted average. The first mandatory requirement is that
employee exposure be eliminated through the implementation of feasible
engineering controls. After all such controls are
implemented and do not fully control to permissible exposure limits, each
employer must rotate its employees to the extent possible in order to reduce
exposure. Only when all engineering or administrative controls have been
implemented, and the level of mercury still exceeds permissible exposure
limits, may an employer rely on a respirator program pursuant to the
mandatory requirements of 1910.134. In addition it is mandatory that no
employee be allowed to consume food or beverages in an area exposed to
mercury (29 CFR 1910.141(g)(2)). Generally, where working conditions or
other practices constitute recognized hazards likely to cause death or
serious physical harm, they must be corrected pursuant to Section 5(a)(1) of
the Occupational Safety and Health Act.
In addition to these mandatory requirements, the National Institute of
Occupational Safety and Health has recommended that the limit be lowered to
0.05 mg/M3; this recommendation is currently being considered by OSHA.
Pending such consideration, the following recommendations are made to ensure
that employee exposure to mercury and its inorganic compounds is controlled
to the permissible exposure limit.
1. MONITORING
a. Initial Evaluation Each employer who has a place of employment
in which mercury or its inorganic compounds are occupationally produced,
reacted, released, packaged, repackaged, transported, stored, handled, or
used should inspect each workplace and work operation to determine if any
employee may be exposed to mercury or its inorganic compounds. Indicators
that an evaluation of employee exposure should be undertaken would
include:
(i) Any information or observations which would indicate
employee exposure to mercury or its inorganic compounds;
(ii) Any measurement of airborne mercury vapor or the dust of
its inorganic compounds;
(iii) Any employee complaints of symptoms which may be
attributable to exposure to mercury or its inorganic
compounds;
(iv) Whenever there has been a production, process, or control
change which may result in an increase in the airborne concentration of
mercury vapor or the dust of its inorganic compounds, or whenever the
employer has any other reason to suspect an increase in the airborne
concentrations of mercury vapor or the dust of its inorganic
compounds.
b. Air Monitoring
(i) Employee exposure measurements should represent the actual
breathing zone exposure conditions for each employee. Any appropriate
combination of long-term or short-term samples would be acceptable, but all
exposures should be calculated on an 8-hour time-weighted average, assuming a
40-hour work week, to arrive at the permissible exposure
limit.
(ii) Accuracy of Measurement. The method of monitoring and
analysis should have an accuracy of not less than plus or minus 20% for
concentrations of airborne mercury vapor or the dust of its inorganic
compounds equal to or greater than the permissible exposure limit. (One
method meeting this accuracy requirement is available in the "NIOSH Manual of
Analytical Methods," Government Printing Office Stock No. 1733-00041.) (iii)
Frequency of Monitoring. Where the employer has determined that employees
are exposed to mercury or its inorganic compounds in excess of the
permissible exposure limit, monitoring should be repeated
quarterly.
2. MEDICAL SURVEILLANCE
Each employer should institute a medical surveillance program for
all employees who are or will be exposed to airborne concentrations of
mercury vapor or the dust of its inorganic compounds above the permissible
exposure limit. The program should provide each employee with an opportunity
for biological monitoring and medical examination performed by or under the
supervision of a licensed physician and provided during the employee's normal
working hours without cost to the employee.
a. Medical Examination
(i) Each employer should provide a medical examination which
includes a complete medical history and physical examination, complete blood
count, routine urinalysis (specific gravity, sugar, protein determinations,
and microscopic examination), and voluntary pregnancy test, where
appropriate, to each employee exposed to mercury or its inorganic compounds
in excess of the permissible exposure limit.
(ii) Medical examinations should also be made available:
(a) To employees prior to their assignment to areas in
which airborne concentrations of mercury or its inorganic compounds are above
the permissible exposure limit;
(b) At least annually for each employee exposed to airborne
concentrations of mercury or its inorganic compounds above the permissible
exposure exposure limit at any time during the preceding six
months;
(c) For each employee whose urine analysis sampling series
indicates elemental mercury level at or above 0.02 mg per liter of urine or
total mercury level in excess of .200 mg per liter of urine, which is not
receding;
(d) Immediately upon notification by the employee that the
employee has developed signs or symptoms commonly associated with toxic
exposure to inorganic mercury or its compounds.
(iii) Where medical examinations are performed, the employer
should provide the examining physician with the following
information:
(a) The reason for the medical examination
requested;
(b) A description of the affected employee's duties as they
relate to the employee's exposure;
(c) A description of any personal protective equipment used
or to be used;
(d) The results of the employee's exposure measurements, if
available;
(e) The employee's anticipated or estimated exposure
level;
(f) The results of the employee's biological monitoring;
and
(g) Upon request of the physician, information concerning
previous medical examination of the affected employee.
b. Biological Monitoring
(i) Urine sampling and analysis should be the biological
monitoring method used. The method of analysis for total, ionic and
elemental mercury in urine is described in the American Industrial Hygiene
Association Journal, September 1974, pp. 576-580. For the analysis at least
100 ml of urine should be collected during a work day when sampling is
scheduled.
(ii) Accuracy of Measurement. Sample analysis should have an
accuracy to a confidence level of 95% as it pertains to the repeatability of
several analyses from any given urine sample.
(iii) Frequency of Monitoring
(a) If possible, a urine sample should be obtained of all
employees who will be assigned to work with mercury or its inorganic
compounds prior to exposure to the work area.
(b) For employees exposed to less than permissible levels
of airborne mercury, urine sampling and analysis should be done every six
months.
(c) For employees exposed to airborne mercury vapor or
inorganic mercury compounds above the permissible exposure limit, urine
sampling and analysis should be performed every three months for each
employee. It should continue at least six months after the last known
exposure above the permissible exposure limit if the employee is available
for sampling.
(d) Where the total mercury level exceeds .200 mg of
mercury per liter of urine, or 0.02 mg of elemental mercury per liter of
urine, sampling should be accelerated to a weekly basis. The activities of
the employees should be observed to detect the potential source of mercury
intake.
(e) If the total mercury level in urine does not decrease
during the one month sampling period, or if the elemental mercury level in
urine does not decrease in two weeks, a physician should be
consulted.
(iv) (a) The results of employee urine sampling should
also be considered as a group exposure by area
of assignment and/or by job description.
Elevated group urine mercury levels should be a
cause for review of operational practices,
process controls, and a change in either or both
to reduce employee exposures.
(b) If several employee urine samples from the same area of
assignment indicate excessive elemental mercury urine levels, corrective
action in the area should be started by the employer
immediately.
c. Physician's Written Opinion
(i) The employer should obtain and furnish the employee with a
written opinion from the examining physician containing the
following:
(a) The signs or symptoms of mercury exposure manifested by
the employee, if any;
(b) A laboratory report of the mercury content in blood or
urine if such analysis is performed by or under the supervision of the
physician, or reported to the physician by a laboratory to which such samples
have been submitted for analysis;
(c) The physician's opinion as to whether the employee has
any detected risk of material impairment to the employee's health from
exposure to mercury or its inorganic compounds or would directly or
indirectly aggravate any detected medical condition;
(d) Any recommended limitation upon the employee's exposure
to mercury or its inorganic compounds or upon the use of personal protective
equipment and respirators; and
(e) A statement that the employee has been informed by the
physician of any medical condition which requires further examination or
treatment.
(ii) The written opinion obtained by the employer should not
reveal specific findings or diagnoses unrelated to occupational exposure to
mercury or its inorganic compounds.
(iii) If the employer determines, on the basis of the
physician's written opinion, that any employee's health would be materially
impaired by maintaining the existing exposure to mercury or its inorganic
compounds, the employer should place specific limitations, based on the
physician's written opinion, on the employee's continued exposure to mercury
or its inorganic compounds.
3. TRAINING
a. Each employer who has a workplace in which elemental mercury or
its inorganic compounds are stored and used occasionally in small quantities,
and where airborne mists, fumes, vapors, or dusts may be accidentally or
intentionally produced and released in the work environment due to handling,
storage, or use should:
(i) Inform employees who work or will be working with mercury or
its inorganic compounds occasionally of potential health
hazards;
(ii) Inform employees of the correct work and storage practices,
written emergency procedures to be followed in case of spills or leaks, and
personal protective equipment necessary in emergencies;
(iii) Provide equipment and/or materials necessary to control
mercury-containing spills or leaks in quantity sufficient to control the
entire amount of mercury or compound used;
(iv) Provide written procedures and means for removal of mercury
or its compounds from body surfaces and working surfaces, machinery, or tools
to be used later for other work activities;
(v) Establish limited areas within the workplace where mercury
or its compounds can be used;
(vi) Inform and local fire department of the exact location of
storage and the hazards in case of fire;
(vii) Assure that the permissible exposure limit is not exceeded
in the work environment during the occasional uses.
b. A training program for all new employees prior to work
assignment and for all affected employees at least annually should be
provided by employers:
(i) Who have a workplace in which mercury metal, its vapors,
fumes, solutions, or inorganic mercury compound dusts, mists, solutions or
vapors are routinely produced, reacted, used, stored, handled in the open
work environment, and where the possibility of exceeding the permissible
exposure limit exists; or (ii) Whose employees may have the opportunity for
routine significant contacts with mercury metal or its inorganic compounds as
solutions, dusts, or mists because such materials are the ingredients or
byproducts of a handling, use, or production process.
c. The training program should:
(i) Advise affected employees of the signs and symptoms of
over-exposure to mercury;
(ii) Instruct affected employees to advise the employer of the
development of the signs and symptoms of overexposure to
mercury;
(iii) Inform employees of the specific nature of operations
which could result in exposure to mercury above the permissible exposure
limit, as well as safe work practices for the handling, use, release,
storage, or disposal of the mercury or its compounds in normal
operations;
(iv) Instruct employees in proper housekeeping practices,
decontamination procedures in the event of a mercury or mercury compound
spill, and fire emergency procedures;
(v) Emphasize the possibility of ingesting mercury by
hand-to-mouth contact when good personal hygiene is not
practiced;
(vi) Inform employees of measures necessary to protect them from
exposures in excess of the permissible exposure limit. The wearing and
turning-in of protective clothing should be stressed;
(vii) Instruct employees as to the purpose, proper use, and
limitations of respirators;
(viii) Provide employees with a description of, and explain the
purposes for, the medical surveillance program;
(ix) Inform employees where written procedures and hazard
information are available on the premises.
4. PERSONAL PROTECTIVE EQUIPMENT
a. Where respirators are required under 1910.1000(e) and 1910.134,
the employer should select and provide an appropriate respirator from the
table below.
b. Recommendations for Respirator Usage at Mercury Concentrations
Above Permissible Exposure Limit
-----------------------------------------------------------
| Airborne Concentration | | |
of Mercury | Recommended Respirator |
----------------------------------------------------------- | 1. Fume, dust,
vapor | (A) A type C supplied-air | | or mist in excess |
respirator with a full | | of 5 mg/M3 | facepiece
operated in | | | pressure-demand or other |
| | positive pressure mode, | |
| or | | | (B) A
self-contained breathing| | | apparatus with a
full | | | facepiece operated in | |
| pressure-demand or other | |
| positive pressure mode. | | |
| | 2. Fume, dust, vapor | (A) A type C supplied-air |
| or mist less than | respirator with a full | | 5 mg/M3
| facepiece operated in | | |
pressure-demand or other | | | positive pressure
mode, | | | or | |
| (B) A self-contained breathing| |
| apparatus with a full | | | facepiece
operated in | | | pressure-demand or other |
| | positive pressure mode, | |
| or | | | (C)
Cartridge type respirator,| | | when approved
(TC) and | | | available. |
-----------------------------------------------------------
c. Only those respiratory protection devices which have been
approved by the National Institute of Occupational Safety and Health under
the provisions of 30 CFR Part 11 should be used.
d. There should be an established in-plant procedure and means and
facilities provided to issue respiratory protective equipment, to return used
contaminated equipment, to decontaminate and disinfect the equipment, and to
repair or exchange damaged equipment. Record keeping of these activities
should be considered, especially on recharge of self-contained breathing
apparatus air cylinders.
5. PROTECTIVE CLOTHING
a. Where protective clothing is required under 1910.132, the
employer should provide and ensure that employees wear appropriate, clean,
protective clothing, such as, but not limited to, coveralls, smocks, aprons,
gloves, shoes, hair covers or hats, in the following situations:
(i) Where employees may be exposed to concentrations of mercury
above the permissible exposure limit; or
(ii) Where the skin, hair, or clothing of employees may have
repeated contact with accumulations of mercury fume, dust, mist, or
solutions.
b. The employer should launder, maintain, and/or dispose of all
contaminated personal clothing discarded by employees.
c. The removal of mercury fume or dust from protective clothing by
blowing or shaking should be prohibited.
d. The employer should ensure that all protective clothing is
removed in change rooms and deposited in marked laundry bags.
e. The employer should inform any person who launders or cleans
mercury-contaminated protective clothing of the potentially harmful effects
of exposure to mercury and of precautions to take, such as not airing or
shaking the clothing to remove mercury fume or dust.
f. Street clothing and street footwear should not be permitted in
the workplace whenever airborne mercury concentrations exceed the permissible
exposure limit or potential contacts with mercury or its inorganic compounds
exist. Contaminated clothing or footwear should not leave the plant except in
packages for laundering, decontamination, or disposal.
g. Employees who work with elemental mercury should turn in all
protective clothing used after each shift of use.
h. If protective clothing and plant footwear is provided for a
longer period of use, they should be stored separately from personal street
clothing, street footwear, food, tobacco products, and other personal
effects.
6. HOUSEKEEPING
a. All exposed surfaces should be maintained free of accumulation
of mercury which, if dispersed, would result in airborne concentrations in
excess of the permissible exposure limit or in a visible dust
cloud.
b. Dry sweeping and the use of compressed air for the cleaning of
floors and other surfaces should be prohibited. If vacuuming is used, the
exhaust air should be properly filtered to prevent generation of airborne
mercury concentrations.
c. Persons not wearing respiratory protective equipment should be
excluded from areas where spills or leaks of mercury or inorganic mercury
compounds have occurred until cleanup has been completed.
d. All hand contact points (such as tools, door knobs, table tops,
etc.) should be maintained free of mercury contamination. If this is
impossible, gloves should be provided.
e. Carpeting should not be used anywhere within the workplace.
Doormats should be treated as mercury-contaminated objects.
f. Used industrial wipe rags, floor cleaning mops, or paper towels
used on mercury contaminated surfaces should be treated as potentially
contaminated. They should not be rehandled, reused, compressed and stuffed,
or dried on in-plant uncontrolled heaters.
7. PERSONAL HYGIENE FACILITIES AND PRACTICES
a. All food, beverages, tobacco products, nonfood chewing
products, and unapplied cosmetics should be prohibited in areas where there
is a likelihood that skin or clothing may come in contact with fume, dust,
mist, or solutions of mercury or where the airborne concentrations of mercury
are above the permissible exposure limit. See the mandatory portion (page 1)
of this Guideline.
b. The employer should ensure that employees or visitors who work
in or need access to areas specified in paragraph 5.a. wash their hands,
forearms, face, and neck before each occasion of eating, drinking, smoking,
or applying cosmetics and at the end of each work shift. All other employees
should be encouraged in this practice.
c. Employers should provide an adequate number of lavatories,
maintained and provided with soap, hand brushes, and towels. Employees
should be instructed in using the handbrushes on fingernails submerged in
washwater. Used paper or fabric towels should be considered and treated as
contaminated.
d. Where employees wear protective clothing or equipment, or both,
change rooms shall be provided in accordance with 1910.141(e).
e. Rings, watches, wallets, combs, and other personal items
usually carried on a person should not be brought in contact with mercury or
its compounds if at all possible. The frames of safety glasses or personal
glasses should be carefully cleaned after each shift of work.
f. Contact lenses should not be used in areas where eyes may be
exposed to vapors, dusts, or mists containing mercury.
|