The Handling, Hazards, and 

Maintenance of Heavy Liquids ir"' 

The Geologic Laboratory 

By Phoebe L. Hauff and Joseph Airey 

GEOLOGICAL SURVEY CIRCULAR 827 

1980 
United States Department of the Interior 

CECIL D. ANDRUS, Secretary 

Geological Survey 

H. William Menard, Director 

Free on application to the Branch of Distribution, U.S. Geological Survey, 604 South Pickett Street, Alexandria, VA 22304 
CONTENTS 

Page 

Abstract • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • . • • • • • • • • • • • • • • • • • • • • • • 1 

Introduction • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 

Acknowledgments • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 

Section I: Properties, hazards, exposure symptoms, and treatment • • • • • • • • • • • • 2 

Bromoform • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 2 

Methylene iodide.................................................. 5 

Acetone • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 6 

Tetrabromoethane. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 8 

Clerici solution • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 9 

Section n: Storage, handling, and spills • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 10 

Bromoform....................................................... 10 

Methylene iodide • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 12 

Acetone • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 12 

Tetrabromoethane. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 12 

Clerici solution • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 13 

Section m: Reclamation of solvents and heavy liquids....................... 15 

Reclamation of diluted solutions • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 15 

Water cascade method........................................ 15 

Refluxing-distillation-condensation method • • • • • • • • • • • • • • • • • • • • • • 15 

Flash-evaporation method..................................... 16 

Modifications to the standard unit • • • • • • • • • • • • • • • • • • • • • • • • • 16 

Recovery and stabilization of heavy liquids • • • • • • • • • • • • • • • • • • • • • • • • . • • 17 

Bromoform • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • . • • 17 

Methylene iodide • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 19 

Tetrabromoethane. • • • • • • • • • • • • • • • • •. • • • • • • • • • • • • • • • • • • • • • • • . • • 19 

Clerici compounds. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • . • • 19 

Fuller's earth reclamation method • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 19 

Selected references • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 19 

Appendix A. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 22 

Properties of some less common dilutants • • • • • • • • • • • • • • • • • • • • • • • • • • • • 22 

Benzene • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 22 

Carbon tetrachloride • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 22 

Dimethyl sulfoxide • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 22 

Isoamylacetate • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 22 

N, N-dimethylformamide •••••••••••••••••••••••••• '• • • • • • • • • • • • 23 

Orthodichlorobenzene. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 23 

Triethylorthophosphate • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 23 

Appendix B............................................................ 24 

Procedure for use of the flash evaporator system • • • • • • • • • • • • • • • • • • • • • • 24 

m 
n.LUSTRA110NS 

Page 

Figures 1-6. Photographs showing: 

1. How an acetone fire can occur in the 

laboratory. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 6 

Z. Protective clothing recommended for heavy 

liquid work • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 10 

3. A type of wire mesh basket used to collect 

saturated heavy liquid papers • • • • • • • • • • • • • • • • • • • • 10 

4. Recommended storage bottles for pure heavy 

liquids and wash • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 0 

5. Spill station • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 11 

6. Acetone storage safety can...................... 13 

7. Diagram of water cascade method for heavy-liquid 

recovery • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 15 

8-10. Photographs showing: 

8. Water cascade apparatus.......................... 16 

9. Refluxing-distillation-condensation apparatus • • • • • • . • 17 

10. Flash evaporator apparatus • • • • • • • • • • • • . . . • • • • • • • • • 18 

TABLE 

Page 

Table 1. Solubilities of acetone and heavy liquids in water ••.•••••••••••••• 15 

IV 
The Handling, Hazards, and 

Maintenance of Heavy Liquids in the 

Geologic Laboratory 

By Phoebe L. Hauff and Joseph Airey 

ABSTRACT 

In geologic laboratories the organic heavy liquids 

bromoform, methylene iodide, tetrabromoethane, and 

clerici compounds have been used for years in mineral 

separation processes. Because the volume of use of 

these compounds is low, insufficient data is available 

on their toxic properties. This report is an attempt to 

summarize the known data from published and industry 

sources. The physical properties, hazards of handling, 

proper storage facilities, and adequate protective 

Clothing are discussed for each compound as well as 

for their common and less-common solvents. Toxicity 

data for these materials is listed along with exposure 

symptoms and suggested first aid treatments. Safety 

for the worker is emphasized. Three reclamation 

methods which recover the solvent used as a dilutant 

and purify the heavy liquid are discussed and 

illustrated. These include: the water cascade, 

refluxing-distillation-condensation, and flash 

evaporation methods. Various techniques for 

restoration and stabilization of these heavy liquids are 

also included. 

INTRODUCTION 

The heavy liquids bromoform (CHBr3), methylene 

iodide (CH2I2), tetrabromoethane (CHBr2)

2,- and 

clerici compounds are organic chemicals of primary 

importance in the mineral separation processes 

followed in many geologic laboratories. For years 

geologists and their technicians have used and abused 

these highly toxic substances. Perhaps this misuse can 

be attributed to a lack of organized and properly 

distributed information relative to the exact hazards 

of these materials. It is the intention of this report to 

consolidate data on heavy liquids from literature 

sources and from personal communications with 

1 

scientists and medical personnel working in the 

geologic and chemical disciplines. Any trade names 

and trademarks in this paper are used for descriptive 

purposes only and do not constitute endo~sement by 

the U.S. Geological Survey. 

The physical properties of each chemical will be 

listed as well as toxicity data. The irdirect and 

obvious hazards of exposure to heavy liquids will also 

be discussed along with first aid treatments. 

Procedures for handling and storage, with emphasis on 

safety of the worker, are itemized. A section on the 

various methods used to reclaim and stab;lize heavy 

liquids and their solvents has also been included with 

an appendix containing data on some of the more 

exotic solvents potentially used as heavy liquid 

dilutants. 

The authors have extensively resear~hed these 

substances. However, any additional data or 

references from readers of this report wodd be most 

appreciated. 

ACKNOWLEDGMENTS 

The authors wish to thank the following people 

from the heavy liquids industry for their information 

and suggestions which contributed significa'ltly to this 

paper: 

Dr. M. W. Anders, Department of Pharmacology, University of Minnesota, Minneapolis, 

Minnesota 55455. 

Richard Doll, E. B. Knight Co., Toms River, 

New Jersey 08753. 

James Svoboda, Columbia Organic Chemicals, 

P.O. Box 9096, Columbia, South Carolina 

29290. 

Jerry Swimmer, National Biochemical Co., Geeliquids Division, 3127 West Lake Street, 

Chicago, lllinois 60612. 
SECTION 1: PROPERTIES, HAZARDS, EXPOSURE SYMPTOMS, AND TREATMENT 

BROMOFORM (tribromomethane)-Properties, hazards, exposure symptoms, and treatment 

Chemistry: CHBr3 

Physical properties: 

Description: Colorless liquid or hexagonal crystals. Odor similar to chloroform (when 

Molecular weight: 

chloroform is used as preservative). 

252.77 

Melting point: 6°-7°C 

Boiling point: 149.5°C 

Density: 2.89 at 20°C 

Density varies due to preservative added. Pure bromoform is w1stable and 

would decompose in several weeks. Preservatives are added to inhibit this 

decomposition. Ethanol and chloroform are commonly used. They are added 

in quantities of 1-2 percent which lowers the density to 2.85-2.88 (J. 

Swimmer, oral commun., 1978). Propylene oxide may also be usE"d (R. Doll, 

oral commun., 1978). It requires only 0.5 percent by volum"! giving a 

somewhat higher specific gravity than does bromoform stabilized by ethanol. 

Flash point: None (nonflammable). 

Weight per liter: 

Vapor pressure: 

Common dilutants: 

(6.36 lbs) = 2.88 kg/liter (Sax, 1978). 

15 mm at 41°C (Weast, 1970). 

Acetone, alcohols, benzene. 

Less-common dilutants: Carbon tetrachloride, triethylorthophosphate N,N-dimethylformamide, isoamylacetate dimethylsulfoxide (Zussman, 1977). 

Toxicity 

The permissible exposure level for bromoform, 

based on its toxicity is established by Federal 

standards. One method of measuring this tolerance 

level is the TLV (Threshold Limit Value). The TLV of 

bromoform is 0.5 ppm, which is 5 milligrams per cubic 

meter of air. The American Conference of Government and Industrial Hygienists (ACGIH) cautions the 

use of TLV as a hazard or toxicity index as TLV is 

intended for use as a positive indicator of exposure 

levels. 

Bromoform is listed as a suspected carcinogen 

(cancer-causing agent) by the National Institute of 

Occupational Safety and Health (NIOSH) (1976). The 

chlorination of drinking water can lead to the 

formation, if appropriate precursors are present, of 

compounds known as trihalomethanes, of which 

bromoform is one (Bunn and others, 197 5; Horvath, 

1976). Because of this association, bromoform and 

other trihalomethanes were tested and bromoform was 

found to be mutagenic (Simmer, 1977; Simmon and 

others, 1977) which is apparently one criteria to 

suspect carcinogenic tendencies. Bromoform, when 

tested by Theiss and colleagues (1977, p. 2717) was 

found to produce "a pulmonary adenoma response" or 

tumors in mice. It is currently being investigated in a 

2-year test program by the National Cancer Institute 

(NCI representative, oral communication, December, 

1979). 

The LD50 for bromoform (that amount which will 

kill 50 percent of a test animal population within 14 

days) is 1,820 mg/kg of body weight. This 

determination was done on mice. The lowest published 

2 

Lethal Dose data (LDL0 ), obtained on rab'1Jits is given 

as 410 mg/kg of body weight (NIOSH, 1977). 

Bromoform is a metabolic poison that may be 

absorbed through the skin and is potentially cumulative 

in the body. It is considered a Class B poison (Sax, 

1968). 

Byproducts of bromoform decomp"Jsition also 

have toxic properties. If overheated to the point of 

decomposition (indicated by a color chang"!), carbonyl 

bromide (COBr2) is produced which is highly toxic 

(Sax, 1968). A second byproduct of decomposition, 

hydrobromic acid (HBr) is a pale yellow liquid which is 

highly corrosive and releases toxic vapors that attack 

metal (O'Connell, 1963). Both compounds pose a 

hazard if inhaled. 

Hazards 

Perhaps the greatest hazard of bromoform and 

similar "heavy liquids" is that the exact nature of the 

hazards involved with their use is only vaguely 

known. Sufficient toxicological research las not been 

done on these compounds to adequately determine 

their long-range effects on the human body. Therefore 

every precaution must be taken in their use. 

Due to the slow evaporation rate of bromoform, 

which is a function of its low boiling point~ the risk of 

atmospheric contamination can be reduced but not 

removed. Because of its fairly high vapor pressure (15 

mm at 41°C), bromoform is transformed into vapor 

with relative ease as compared to methylene iodide 

(1.01 mm at 25.3°C), and even acetylene tetrabromide 

(10 rom at 114°C). Therefore, additional respiratory 

precautions combined with adequate ventilation are 
essential because of the toxic fumes released during 

the use of bromoform. A major consideration is the 

fact that once bromoform is smelled in the air, it is an 

indication that the threshold limit for a person for an 

8-hour day (0.5 ppm or 5 mg/m3) may have been 

reached or is being reached (Sax, 1968). A person 

subjected to the odor of bromoform may become 

accustomed to it and not notice the subsequent 

saturation of the air until more unpleasant side effects 

occur. However, please note that the sense of smell is 

not a reliable medium for the determination of 

exposures. 

An insidious hazard of bromoform is that it 

metabolizes to carbon monoxide and can substantially 

raise the level of CO in the bloodstream (Anders and 

others, 1978; Ahmed, Kubic, and Anders, 1977; Stevens 

and Anders, 1978). Carbon monoxide has 200 times 

more affinity for the iron in hemoglobin than oxygen 

and therefore diminishes the ability of the blood to 

carry oxygen. An additional problem is that in the 

presence of CO hemoglobin is more reluctant to give 

up the oxygen it already carries. As CO saturation of 

the red blood cells occurs a person becomes lightheaded, dizzy, and eventually loses consciousness. 

Fifty-percent saturation is extremely serious; close to 

60 percent can cause death. Carbon monoxide 

produced biosynthetically, as from the bromoform 

interaction, tends to remain in the body longer than 

does CO from more primary sources. Smoking can 

accelerate the effects of carbon monoxide 

overexposure as smokers have approximately a 7-

percent CO saturation initially before any exposure to 

bromoform can add to this. The preceding information 

comes from a discussion with Dr. Anders of the 

University of Minnesota. His research to date has 

been done with rats. 

Bromoform is a contact poison and can be 

introduced into the body by external exposure. 

Hydrocarbons such as bromoform have an affinity for 

body oils and tend to also move into fatty tissues 

(Bowman, Borzelleca, and Munson, 1978). 

The decomposition byproducts, carbonyl bromide 

and hydrobromic acid, produce dangerous vapors and 

require immediate ventilation. 

When bromoform is dissolved with acetone, the 

mixture becomes highly flammable. Fires from this 

solution are extremely hazardous because as the 

bromoform is heated, and therefore decomposes, toxic 

fumes are liberated. 

Geologists using or recovering bromoform in 

fieldwork must use extra care that proper ventilation 

is provided-especially when working in air-conditioned 

trailers or with quantities in open funnels. 

Exposure Symptoms 

A chemical may have an acute effect on the 

body which is an immediate or almost immediate 

manifestation of exposure symptoms and it may also 

3 

cause chronic or long term effects from exr0sure. As 

can be seen from the cited references~, research 

programs to determine precisely what deleterious 

effects bromoform has on the human systetr have only 

recently been undertaken. Some data has been 

extrapolated from similar compounds. Unfortunately, 

when internal organs such as the liver and l'~dneys are 

involved, definitive data on humans is many times only 

available after an autopsy. With a chemical as exotic 

as bromoform the appropriate tests are rarely 

performed. It is not always possible to determine if 

the damage is caused by the passage of a compound 

through the system or its retention therein. It is the 

experimentally unsubstantiated opinion of several 

researchers in this area that, although bromoform is 

retained within the system for a longer period of time 

than the 11 average 11 alien substance, it is eventually 

flushed from the body; but that the amount acquired 

from overexposure is such that the bromoform appears 

to be perhaps indefinitely retained. 

Careless use of bromoform, failure of ventilation 

systems, or spills can cause exposure over the limits 

considered acceptable. Some of the synptoms of 

overexposure are: tearing, headaches, excersive saliva 

flow, nausea, reddening of the face, dizziness, 

drowsiness or a state of apparent inebriatio"l, or, with 

prolonged exposure, deep narcosis and death (Sax, 

1968). Skin contact may be followed by burns that 

appear as second-degree inflammations. 

It is important to note that the cons11mption of 

alcoholic beverages before, during, or afte~ exposure 

to bromoform may enhance the exposure symptoms 

and increase the effects of the combined exposures 

(National Biochemical Co., 1975; Sax, 1968). As noted 

in the previous section, smoking may also escalate the 

effects of bromoform on the system causin~ dizziness, 

headaches, and even loss of consciousness (Dr. Anders, 

oral commun., December 1979). 

Bromoform can cause systemic damage. 

Repeated exposure can lead to excessive damage to 

the liver, kidneys, heart, and lungs. Experiments with 

rats by Bowman, Borzelleca, and Munson (1978) of the 

Virginia Commonwealth University, showed that 

bromoform infiltrates the fatty tissue of th~ liver and 

also can cause hemorrhaging in the kidneysi adrenals, 

lung, and brain of the test animals. 

Bromoform is potentially cumulative in the body 

organs and, therefore, repeated overdoses of it are 

highly dangerous. An internal lethal dose is 2-4 ounces 

for a 150-pound man (Carver, 1971). 

An additional problem relative to d<:!termining 

the 11 safe11 limits of exposure to bromoform is the fact 

that each person can react differently to the same 

volutpe of vapors. Workers whose prior working 

history shows that they are overly se"lsitive to 

bromoform vapors should not be allowed to vrork where 

exposure is assured or likely. 
Treatment 

Countermeasures for overexposure victims are: 

remove the victim to fresh air, administer artificial 

respiration and oxygen if needed, and get medical 

assistance immediately. 

For skin contact, flush thoroughly with water and 

wash with soap. Skin oils will absorb the bromoform 

and therefore they must be dissolved with a strong 

soap and washed away. Remove contaminated clothing 

and wash it before reuse. 

If the victim exhibits advanced inhalation 

exposure symptoms, tests for carbon monoxide 

poisoning should be considered. This is perhaps easier 

to determine than the presence of bromoform, 

bromides, or bromine in the blood. Bromine blood 

content can apparently be tested for by electron 

4 

capture gas chromatography (Dr. Anders, oral 

commun'., December 1979). 

First aid measures given by th~ American 

National Red Cross (1973, p. 101-102) for inhaled 

poisons are: 

1. Remove the victim from the poison source. 

Be sure you do not become a victim 

yourself. 

2. Have oxygen brought to the seen~. 

3. 

4. 

Loosen the victim's clothing, give artificial 

respiration if needed. 

Be sure to remove any saturated clothing 

from the area. 

Cases of overexposure should be referred to a 

physician as soon as possible. The rescuers should be 

sure to protect themselves and to wear protective gear 

when helping others. 
METHYLENE IODIDE (diiod.omethane)-Properties, hazards, exposure symptoms, and treatment 

Chemistry: CH2I2 

Physical properties: 

Description: 

Molecular weight: 

Straw-colored, clear liquid. 

267.9 

Melting point: 5°-6°C 

Boiling point: 181°C 

Density: 3.325 at 20°C 

Vapor pressure: 

Flash point: 

1.01 rom at 25.3°C {J. Swimmer, oral commun., 1979). 

None. {Vapor will burn if exposed to open flame.) 

Weight per liter: 3.32 kg/liter {Sax, 1968; Weast, 1970). 

Common dilutants: Acetone, alcohols, benzene. 

Less-common dilutants: Carbon tetrachloride, triethylorthophosphate, N,N-dimethylformamide, orthodichlorobenzene {Zussman, 1977). 

Toxicity 

A literature search reveals that there is minimal 

documented data on methylene iodide {MEI). This lack 

of data may be a function of limited use of MEI in 

industry and the sciences. {See National Biochemical 

Co. Bull. No. 31, 1975, for list of physical properties 

and arbitrary precautions used by that company in 

their manufacturing processes.) 

The TLV is estimated to be 50 ppm per 8-hour 

working day. This value is experimentally unsupported 

and its use as a standard is therefore suspect. This is 

much higher than 0.5 ppm TLV for bromoform determined by the ACGIH {American Conference Governmental Industrial Hygienists). Until further tests are 

conducted on MEI and a specific standardized TL V is 

established, precaution is advised. Due to the high 

vapor density and low vapor pressure, MEI can perhaps 

be used relatively safely with adequate ventilation as 

compared with other halogenated hydrocarbons. A 

TLV of 25 ppm is suggested by Jerry Swimmer {written 

commun., 1979) based on personal experience within 

his company. An LD 50 for methylene iodide is given in 

NIOSH {1977) as 830 mg/kg. The determination was 

done on a mouse. 

Hazards 

The hazards of MEI are mostly unknown. It is, 

however, a probable irritant and a possible narcotic in 

high doses. It has been known to cause local 

anesthesia of nasal mucous areas from moderate and 

high vapor concentrations. Mr. Swimmer indicates 

that in his facility and within his experience in the 

industry no one to his knowledge has lost consciousness 

due to methylene iodide vapors {J. Swimmer, written 

commun., 1979). 

Like bromoform, methylene iodide has been 

shown to metabolize carbon monoxide and raise the 

level of CO in the blood with all the attendant 

5 

symptoms and problems described in the bromoform 

section {Kubic and others, 1974; Kubic and Anders, 

1975). 

Methylene iodide will decompose upon exposure 

to light and heat and will emit toxic iodine fumes. 

MEI itself is not flammable, but the vapor will burn if 

exposed to open flames, releasing large amounts of 

free iodine {Sax, 1968). Iodine possesses toxic 

properties similar to those of methylene iodide. 

MEI is often diluted with acetone-as a washing 

agent or to lower the density of MEI. It must be 

remembered that, although MEI is not itself 

flammable, it becomes so when mixed with acetone. A 

fire will pose added danger as MEI iodine vapors will 

be released into the air during combustion. 

Exposure Symptoms 

When using MEI, the proper precautions for 

working with a toxic liquid should be followed. These 

preca'!ltions include adequate ventilation and 

protective laboratory clothing. MEI should be 

considered to be an anesthetic in high vapor 

concentrations-adequate ventilation is necessary. 

Overexposure can result in respiratory complications. 

Excessive overexposure may bring about 

unconsciousness. MEI is rated as a narcotic by Sax 

(197 5). This classification is refuted by Jerry 

Swimmer (written commun., 1979) who cites loss of 

consciousness as a criteria of a narcotic substance. 

Because the vapor pressure of MEI is so low, the 

chances are slight of MEI vapors saturating the 

atmosphere sufficiently to cause overexposure to the 

point of unconsciousness in the worker. 

Treatment 

The general procedures listed in the bromoform 

section under "Treatmene' can be considered to apply 

to MEI exposures also. 
ACETONE (dimethyl ketone, ketone propane, propanone)-Properties, hazards, exposure symptoms, 

and treatment 

Chemistry: 

Physical properties: 

Description: 

Molecular weight: 

Melting point: 

Boiling point: 

Soluble in: 

Density: 

Flash point: 

Autoignition: 

Vapor pressure: 

Weight per liter: 

Explosive limits: 

Clear, colorless liquid having a mintlike odor and a sweet taste; in the context 

of the present report, acetone is referred to in its use as a dilutant for 

bromoform and methylene iodide. 

58.08 

-94.6°C 

56.48°C 

Water, alcohol, ethyl ether, benzene. 

0.797 

-17.8°C 

538°C (1,000°F). 

400 mm at 39.5°C 

0. 79 kg/liter (6.59 lbs/gallon). 

Lower, 2.6 percent; upper, 12.8 percent (Sax, 1968; Weast, 1970). 

6 

Figure 1.--How an acetone fire can occur in the 

laboratory. ~ Acetone bottle left near a heat lamp; 

expansion causes drips onto the laboratory bench. ~ 

Acetone bottle on fire. Note how stream of acetone 

from spout feeds on fire. £, Ruptured acetone 

bottle. Photographs by Louise Hedricks. 

Toxicity 

The TLV of acetone is 1,000 ppm in air or 2.4 X 

103 milligrams per cubic meter of air. Acetone is a 

narcotic in concentrations greater than the threshold 

limit. 

Hazards 

Acetone is classified as an inflammable liquid 

and is extremely dangerous when exposed to heat or 
flame. Even mixed with water, a solution of greater 

than 10 percent acetone is flammable, having a flash 

point of 2.7°C. The fact that acetone is extremely 

volatile adds to its hazard potential. Explosive vapors 

can soon saturate the air in the event of a spill. Keep 

acetone away from any heat or possible ignition 

source. Heat lamps used to dry samples in the 

laboratory are a very real danger. Acetone placed 

close to a heat lamp will volatilize and spill all over 

the laboratory counter. Figure 1 shows how an 

acetone fire can occur. 

Acetone may also react vigorously with oxidizing 

materials (Sax, 1968). · 

Exposure Symptoms 

The volatile nature of acetone poses a problem if 

acetone is used in a poorly ventilated area. The 

symptoms of overexposure are dizziness, headache, 

7 

coughing, irritation of the respiratory tra-::t and, in 

more extreme cases, unconsciousness (Sax, 1968). The 

symptoms of slight exposure (dizziness, heaiache) are 

quickly relieved by removing the victim to fresh air. 

The effects will disappear in about 2. hours. Prolonged 

exposure will cause more acute headache ani dizziness 

and may result in the loss of consciousness. 

Treatment 

Remove the victim to fresh air and administer 

artificial respiration if necessary; immediate medical 

help is imperative. 

For external exposure: acetone will di~solve skin 

fat upon contact and cause dryness. Use of hand lotion 

will help avoid cracking and relieve irritation. 

If acetone is splashed in the eye, irr1gate with 

large amounts of water and call a physician. 
TETRABROMOETHANE (acetylene tetrabromide)-Properties, hazards, exposure symptoms, and treatment 

Chemistry: (CHBr2)

2 

Physical properties: 

Description: 

Molecular weight: 

Colorless to yellow liquid. 

345.7 

Melting point: -1°C 

Boiling point: 

Density: 

151°C at 54 mm (Sax, 1975). 239.42°C at 760 mm (Weast, 1970). 

2. 96 at 25°C. 

Flash point: None. 

Weight per liter: 

Vapor pressure: 

2.96 kg/liter (Sax, 1968; O'Connell, 1963). 

10 mm at 114°C (Weast, 1970). 

Common dilutants: Acetone, alcohols, benzene. 

Less-common dilutants: Carbon tetrachloride, triethylorthophosphate (Zussman, 1977). 

Toxicity 

The TLV of tetrabromoethane is set by the 

ACGIH at 1.0 ppm (14 mg/m3 air). This substance, 

like bromoform, is a metabolic poison and a narcotic in 

high concentrations (Sax, 1968). 

One of the byproducts of tetrabromoethane when 

heated to decomposition is carbonyl bromide (carbon 

oxybromide), COBr2• It is listed (Sax, 1975) as 

extremely poisonous, and is present as a vapor. Also 

formed in the presence of water is hydrobromic acid, 

HBr, an extreme corrosive. 

Hazards 

The hazards are similar to those of bromoform, 

with adequate ventilation imperative for workers' 

safety. Both internal and external exposure pose 

hazards because the substance is both an irritant and a 

metabolic poison. The odor may not readily be noticed 

by workers as they will become accustomed to it. 

Hooded ventilation systems are necessary when 

working with tetrabromoethane. 

8 

Exposure Symptoms 

Exposure over the accepted limits to the fumes 

can cause systemic problems of varying degrees. 

Slight exposure causes tearing and drowsiness. Single 

exposures of this type pose little danger of permanent 

injury. Repeated exposure, however, becomes a severe 

hazard and can result in long-term inju"t"y or death. 

Major damage can be done to the kidne;•s and liver, 

where toxins accumulate during blood filtration. If the 

toxic material is introduced faster tha""t it can be 

expelled, poisoning will occur. This explains the 

danger of cumulative poisoning by rep~ated slight 

exposure. 

Exposure to the skin is not serious if the 

tetrobromoethane is washed off immediately. If not, 

it can cause severe burns, and absorption through the 

skin may cause systemic poisoning. 

Treatment 

Treatments for overexposure are the same as 

those for bromoform. Tetrabromoethane effects are 

also enhanced by the use of alcoholic beverages. 
CLERIC! SOLUTION (thaltium-malonate-formate)-Properties, hazards, exposure symptoms, and treatment 

Chemistry: CH2(COOT1) 2·HCOOTl"H20 

Physical properties: 

Description: Clerici solution is made up of equal weights of thallus formate (CH2(COOT1) 2) 

and thallus malonate (HCOOTl) in distilled water. A solution of 

approximately 135 ml is made up from 300 g of each thallium compound 

dissolved in 40 g of distilled water. Several other methods of preparation 

for clerici solution are described by Vassar (1925). Thallus monalate and 

formate are available either as salts or in solution (Jahns, 1939). Odorless 

liquid, clear to amber in color. Highly mobile liquid (pours as water). 

Density: 4.28 at 20°C. Density increases with temperature and thallium salt 

concentration to approximately 5.0 at 90°C in a saturated solution. 

Boiling point: 125°C at 1 atmosphere (Sax, 1968; Rosenblum, 1974). 

Common dilutant: Distilled water. 

Toxicity 

The threshold limit value for thallium compounds 

has been set by the ACGIH at 0.1 mg/m3 air. 

Hazards 

Thallium compounds carry a hazard reputation 

that is indeed sobering. Thallium compounds are used 

in rat poisoning. The risks of atmospheric 

contamination can be limited with proper ventilation 

during use and storage. Because the compounds are 

odorless and usually colorless, they give no warning of 

their presence. 

Heating clerici solution to vary its density gives 

off highly toxic, heavy-metal fumes. The danger of 

exposure cannot be overstressed. Clerici solution 

should never be exposed to an open flame. It should be 

heated only over a steam bath. The high mobility of 

clerici solution may create additional hazards; if 

spilled, the solution can move rapidly into small areas 

and cracks and remain there undetected. 

Clerici compounds should be used only as a last 

resort when all other methods of separation are 

ineffectual. If the compounds are used, extra 

precaution should be instituted in the working area. 

These precautions are discussed in detail in the later 

section on handling. 

Exposure Symptoms 

The greatest dangers to the laboratory user are 

inhalation and exposure to the skin. Repeated 

exposure to thallium compounds is cumulative in the 

body and can cause serious physical impairment or 

9 

death. Thallium and its salts are absorbed through the 

skin. 

External exposure to thallium salts is 

immediately irritating to areas of contact. Because 

clerici is odorless, atmospheric contamination may go 

unnoticed until acute internal exposure has taken 

place. The symptoms of thallium poisoning resemble 

those of lead and other heavy-metal poisoning. Some 

symptoms are: swelling of the lower extremities, joint 

pain, abnormal sensitivity in feet or hands (burning and 

(or) tingling), mental confusion, paralysis, inflammation of the kidneys, abnormal white blood count, 

and loss of hair of the head and body. Fatal poisoning 

has been known but is not common. (Sax, 1968). 

A white deposit may appear on the skin after a 

slight contact with thallium salts. If the skin is 

properly and promptly washed with soap and water, 

this deposit will usually disappear within several days 

without any apparent injurious effects (Engineered 

Materials, 1969). 

Treatment 

Remove the victim from the area of 

contamination and obtain immediate medical 

assistance. If any of the before-mentioned symptoms 

appear, medical care is imperative. 

Wash the skin exposed to the chemical 

immediately with soap and water. If the chemical is 

ingested, force the victim to drink large volumes of 

fluids until medical help is available. Give first aid 

treatments only after medical help has been called for 

(McElwee, 1979). 
SECTION II: STORAGE, HANDLING, AND SPILLS 

BROMOFORM-Storage, handling, and spills 

Storage 

Bromoform, like methylene iodide, is a 

halogenated hydrocarbon and will break down and 

darken due to free halogens emitted by exposure to 

heat and light (J. Swimmer, written commun., 1978). 

It should, therefore, be stored in amber glass bottles in 

a cool, dry place; preferably in an area of good 

ventilation. 

Handling 

Any time heavy liquids are handled, it is 

imperative. to wear gloves, a rubber apron, and goggles 

or safety glasses (fig. Z). The gloves should be checked 

for cuts or tears. Rubber gloves are advised; most 

plastics will deteriorate with prolonged exposure to a 

heavy liquid. Work with bromoform should be 

performed under a fume hood that should draw 160 

feet per .minute (fpm) face velocity. Less draw 

violates the OSHA regulation that if the TL V is 

exceeded, the hood is not venting properly. The 

Figure Z.-Protective clothing recommended for 

heavy-liquid work. !:., Rubber apron; ~ rubber 

gloves; .f., safety goggles; Q, respirator with 

replaceable filters. Photograph by Louise Hedricks. 

10 

Figure 3.-A type of wire mesh basket used to collect 

saturated heavy-liquid papers. Photograph by Louise 

Hedricks. 

Figure 4.-Recommended storage bottles for pure 

heavy liquids and wash, appropriately labeled. 

Photograph by Louise Hedricks. 

additional precaution of wearing a filtered respirator 

is also advised. Filter paper and absorbent towels or 

tissues contaminated with bromoform should be 
removed from the laboratory and not left in open 

waste containers outside the hood. A wire mesh 

basket (fig. 3), suspended or set in the hood, can be 

used during the day, while the hood is operating, to 

evaporate heavy liquid and solvent from saturated 

filter paper and tissues. It should be emptied into a 

large and, if possible, ventilated or outside disposal 

container at the end of the job or the day. 

In the transfer of bromoform, care should be 

taken with any plastics exposed to the liquid. Most 

laboratory plastics will deteriorate and eventually fail 

with prolonged exposure to bromoform. Glass and 

teflon should be used whenever possible (Cole-Farmer, 

1977). Figure 4 shows recommended storage bottles. 

Any area where heavy liquids or their products are 

used must be adequately ventilated and care must be 

taken that fumes are not recirculated into adjacent 

ventilation systems. 

Remember to prominently label any storage area 

or bottles containing a heavy liquid. 

IRST AID 

Spills 

In the event of a large. spill, several precautions 

should be taken. Make certain all potential ignition 

sources are neutralized. Toxic vapors from the spill 

create the greatest problem, especially if the spill 

occurs outside the hood area. If possible, tum off 

central air-conditioning to keep fumes from 

nonlaboratory areas. Proper equipment must be worn 

to . avoid vapor inhalation. A self-contained breathing 

unit (preferable) or a respirator with detachable, 

renewable filters should be worn by each member of 

the cleanup party. Protective clothing is essential. 

Rubber aprons are recommended as are rubber gloves 

and goggles because cloth laboratory coats may absorb 

the heavy liquid. A cleanup kit of absorbent material 

(fuller's earth or. kaolin powder) should be kept close to 

the area where heavy liquids are used. A typical spill 

station containing the appropriate items for spill 

cleanup is shown in figure 5. The fuller's earth is 

Figure 5.-Spill station in the laboratory showing basic equipment and neutralizing materials. Photograph by 

Louise Hedricks. 

11 
sprinkled over the spill and allowed to absorb the 

heavy liquid. Then, using a broom and dustpan, sweep 

up the now-saturated absorbent. Transfer it to filter 

paper in a funnel set into a filter flask attached to a 

vacuum. By filtering under a high vacuum there is a 

chance of recovery of some of the heavy liquid. 

Because fuller's earth is highly absorbent, recovery is 

not complete, but worth the effort. After the mess is 

removed from the floor or countertop, pour acetone on 

the area and wipe clean to remove final traces of 

heavy liquid. 

A small spill can be cleaned by squirting the spill 

with acetone and wiping it up with absorbent paper. 

The papers are disposed of as described in the section 

on handling. 

Great care should be taken to avoid skin contact 

with chemicals and cleanup material and inhalation of 

toxic vapors. 

METHYLENE IODIDE-Storage, handling, and spills 

Storage 

A main consideration in the storage of methylene 

iodide is that it is highly sensitive to light and 

decomposes quickly upon exposure. 

When ME! decomposes, it darkens to an opaque, 

blood-red liquid due to the free iodine that is liberated 

with oxidation. To retard decomposition, store ME! in 

a dark, cool place, tightly sealed in amber glass 

bottles. Good ventilation in the storage area is also 

recommended. A small piece of copper or silver wire 

mesh in the bottle will theoretically maintain the 

'stability of the liquid and thus the lighter color for 

extended periods of time when stored in tightly closed 

containers away from heat, light, air, and moisture 

(National Biochemical Co., 197 5). 

Handling 

Transfer of ME! should take place only in areas 

of adequate ventilation and should use nonreactant 

tubing. In the various references available, no data 

was found on the resistance of various plastics to 

ME!. Any plastic to be used in prolonged contact with 

methylene iodide should be tested before use. A wise 

assumption, for safety reasons, is that ME! reacts to 

plastics in a fashion similar to bromoform. 

The same precautions listed in the bromoform 

section relative to protective clothing, handling, and 

air contamination also apply to methylene iodide. 

Spills 

Methylene iodide spills are handled in the same 

manner as those involving bromoform. 

lZ 

ACETONE-Storage, handling, and fires 

Storage 

Acetone will dissolve some types of plastic and, 

therefore, care must be taken in its storage. Acetone 

is safely kept in containers of teflon, polypropylene, 

polymethylpentene, and glass (Cole-Parmer, 1977}. It 

cannot be stored or transferred in polycarbonate or 

polyvinyl chloride containers. The plastic laboratory 

gloves and aprons used when handling acetone must be 

constantly checked for signs of deterioration. Acetone 

must also be stored in a well-ventilated area. 

Handling 

When transferring acetone from a larger drum, 

use a self-closing faucet and be certain that the drum 

is effectively grounded; static electricity could 

generate a spark that may lead to a fire or explosion. 

Remember that the flash point of acetone is -17.8°C. 

Never transfer acetone by means of compressed air as 

acetone is too volatile a substance. For storage in an 

active laboratory for daily access, use an approved 

safety-storage can with appropriate dispenser. Avoid 

storing large volumes in the laboratory. Figure 6 

shows a grounded storage can with an automatic 

closing dispenser and a safety can. 

Any time there is a chance of external exposure, 

protective clothing should be worn, including apron, 

goggles, and gloves. 

Fires 

Because acetone is so highly inflammable, the 

chance of a fire is great in any laboratory using 

acetone. In the event of a fire, a co2, foam or dry 

chemical extinguisher will smother the blaze. Water 

will only be effective when there is less than 10 

percent acetone remaining (National Safety Council, 

1963). 

Also remember that any heavy liquid diluted with 

greater than 10 percent acetone will burn just like 

acetone itself. 

TETRABROMOETHANE--Storage, handling, and spills 

Storage 

This liquid, like bromoform, is a halogenated 

hydrocarbon, and is similarly unstable. Tetrabromoethane should be stored in a cool, dark, ventilated area 

in glass or nonreactive plastic. 
Figure 6.-Acetone storage safety can. Acetone 

should be stored in an approved safety can that is 

grounded for sparkless transfer. Photograph by 

Louise Hedricks. 

Handling 

When transferring tetrabromoethane, bromoform, or methylene iodide, keep in mind that plastics 

and rubbers swell and soften with exposure. 

Fluorinated polymers (teflon, Kel-F) show the greatest 

resistance. A recommended procedure is to test a 

proposed plastic or rubber before using it in a transfer 

system. Prior testing will eliminate the problems of 

cleaning up after a messy spill caused by a 

deteriorated bottle. Transfer should be carried out 

only in a well-ventilated area, and protective clothing, 

such as that described for bromoform, should be worn 

(O'Connell, 1963; Sax, 1968). 

13 

Spills 

Tetrabromoethane spills are handled in the same 

fashion as bromoform spills. 

CLERIC! SOLUTION-Storage, handling, and spills 

Storage 

As a safety precaution, thallium formate and 

thallium malonate should be stored in a solid form, 

especially if storage is for any appreciable length of 

time. These are highly poisonous compounds and the 

liquid phase is more mobile than the solid crystals. 

There is a greater chance of a spill and subsequent 

spread of this highly toxic substance through the 

laboratory. 

Whether clerici is stored as a solid or in the lessdesirable liquid phase it must be placed in a secluded 

area, segregated from high-use chemicals and 

prominently labeled as to extreme toxicity and hazard 

and tightly sealed. Clerici compounds are not lightsensitive. They should be stored in glass containers as 

they will corrode metal and become discolored. 

(Engineered Materials, 1965). 

The lethal aspects of clerici cannot be 

overemphasized. 

Clerici compounds are dissolved in distilled 

water for use in mineral separations, but after use the 

water is evaporated off until dry. Care must be taken 

not to evaporate the water at a temperature higher 

than 130°C, as the thallium compounds decompose at 

this temperature (Browning, 1961). 

Handling 

The greatest consideration in handling these 

compounds is the extreme toxicity of thallium. 

Thallium compounds are readily absorbed through the 

skin (the damage caused was previously discussed 

under toxicity). Extreme caution must be used in 

handling these compounds and includes wearing a 

respirator, protective clothing, gloves, and safety 

goggles (O'Connell, 1963). Gloves should be rubber, 

neoprene, or latex (0.014 in. thick) and aprons should 

also be rubber (Engineered Materials, 1965). Any 

protective gear must be thoroughly cleaned inside and 

out after exposure to clerici compounds. Use of these 

solutions should be restricted to a posted area of the 

laboratory so that an unaware worker will not be 

exposed to them. As an added precaution, all 

operations involving thallium should be performed 

under a ventilated hood with a face velocity of 170-

200 fpm. 

Smoking, drinking, and eating are to be 
prohibited in any area where thallium or its compounds 

are handled. 

Instructions for handling should be reviewed in 

detail before using clerici solutions in mineral 

separation procedures (see Rosenblum, 1974; Vassar, 

1925; Jahns, 1939). 

14 

Spills 

Use water-saturated paper towels to clean up 

spills. Dispose of waste material with all 

precautions. Wash down spill area thoroughly with 

soap and water. (Engineered Materials, 1965). 
SECTION m: RECLAMATION OF SOLVENTS AND HEAVY UQUIDS 

Due to the high cost of heavy liquids, the 

increasing costs of solvents, and the large volumes of 

these materials used in mineral-separation processes, 

it has become economically expedient to recover as 

much as possible for reuse. Because these compounds 

are relatively unstable, chemical deterioration may 

occur, thus decreasing their usefulness. In this 

section, several methods are described for the 

recovery of solvents and the rejuvenation of diluted or 

decomposed heavy liquids. 

Reclamation of Diluted Solutions 

Water Cascade Method of Heavy Liquid Recovery 

The principle of the water-washing method is 

based on the relative insolubility of the heavy liquid in 

water as compared to the high solubility of the 

dilutant. Table 1 compares these solubilities at 20°C. 

Table !.-Solubilities of acetone and heavy 

liquids in water 

Data from Muller, 1977; and Benjamin, 1971 

Substance Solubility 

Acetone Infinite 

Bromoform 0.319 g/100 ml H2o 

Tetrabromoethane 0.065 g/100 ml H2o 

Methylene iodide 1.42.0 g/100 ml HzO 

A typical water-washing system is described in 

Hutchinson (1974, p. 12.2.). The heavy liquid-solvent 

mixture is placed in an apparatus such as that shown in 

figures 7 and 8 and washed with a constant flow of 

water which carries away the dilutants or solvents. 

This washing process is fairly time-consuming as it 

takes about 2. hours per 1,000 milliliters of mixture. 

The diluted heavy liquid is poured into a large 

separatory funnel (funnel 1 in fig. 8). Water is 

introduced through a glass tube that runs to the 

bottom of the funnel. Water is bubbled through the 

heavy liquid, dissolving the solvent and floating it 

above the heavy liquid, due to the lesser specific 

gravity of the solvent. The solvent then mixes with 

the water. The water-solvent mixture then flows into 

funnels 2. and 3 (fig. 8) where any heavy liquid that 

may have been carried along is trapped. The water 

leaves the system by a drainage tube and is disposed 

of, usually down a waste drain. 

15 

WASHING 

VESSEL 

TRAP I TRAP 2 

-18-!lclll fUNNEl 

- WATEI\ 1Nl£T TUBE 

1

1

tam111 80P.E CAPILLAI\Y 

-wASH INC INLET TUN: ( 111 UNG~ Of 

WASHING VESSEL } 

-TO WITHIN 2 c• Of IOTTOH 

OF WASHING VESSEL 

DETAIL DIAGRAM Of HEAD Uli!T fOR 

WASHING VESSEL 

TO 

WASTE 

VIA FILTER PUMP 

IF NECESSAP.Y 

Figure 7.-Water cascade method for heavy-liquid 

recovery. Design from Benjamin (1971, p. 616). 

Published with permission. 

The advantage of this method is the relatively 

low cost of the apparatus used. However, all of the 

solvent is lost, as is the heavy liquid at the waterheavy liquid interface, and a percentage of the heavy 

liquid that is water-soluble. 

A variation on this system would be to bubble air 

through the solvent-heavy liquid mixture following the 

general principles just described. (Donald Lee, oral 

commun., 1979). 

Refluxing-Distillation-Condensation Method 

for Heavy-Liquid Recovery 

The refluxing-distillation-condensation method 

utilizes a direct heat source with variable temperature 

controls to evaporate acetone (or similar solvent) from 

a diluted heavy-liquid solution. Water is circulated 

throughout the condensing tube where the evaporated 

acetone is recondensed. (See figure 9.) The acetone is 

then drained off, with the heavy liquid remaining in 

the evaporating flask. The method is slow and must be 

constantly monitored. The temperature of evaporation 

needed for acetone is 56°C. If the heavy liquid is left 

exposed to this temperature for too long, it will 

decompose, forming toxic byproducts and darkening to 

a point of opacity. Once the heavy liquid is thus 

oxidized, rejuvenation is extremely difficult. With 

proper precautions, however, including the 
SAFETY GLASS 

REQUIRED 

IN THIS AREA 

1 

Figure 8.-Water cascade apparatus, U.S. Geological 

Survey laboratory, Denver, Colorado. 1, Separatory 

funnel; 2, 3, additional funnels to trap heavy liquid. 

Photograph by Louise Hedricks. 

stabilization of the distilled heavy liquid, this method 

has proved to be effective. 

Flash-Evaporation Method of Heavy-Liquid and 

Solvent Recovery 

The flash evaporator provides a closed, contained 

environment for the separation of mixtures of organic 

solvents and organic heavy liquids. The system 

operates under decreased pressure which lowers the 

boiling point of the solvent and allows for differential 

evaporation at reduced temperatures. This method 

reclaims both solvent and heavy liquid and operates at 

a lower temperature which does not oxidize the heavy 

liquid as does the reflux-distillation method. 

The system, illustrated in figure 10, is a Buchler 

flash evaporator, model PTFE-1gn. Generalized, the 

following procedure is applicable to other types of 

commercially available flash-evaporation units. 

The apparatus has six major parts: (1) evaporating pan and water bath; (2) evaporating flask; (3) 

thermoregulator and heater; (4) rotatable motor; (5) 

spiral condenser coil; and (6) collecting flask. 

A heavy liquid-solvent mixture is introduced into 

the evaporating flask, which is immersed in a 

16 

temperature-controlled water bath. The pressure in 

the system is then reduced to a 10-15 mm vacuum (the 

value recommended in the Buchler operating 

instructions) to facilitate evaporation of the solvent. 

A lesser vacuum will slow the process somewhat but 

will still give efficient results. If the available 

vacuum source cannot reach this value, the 

temperature can be raised to improve evaporation. 

However, care must be taken not to raise the 

temperature too high or oxidation of the heavy liquid 

will occur. 

There are several advantages to a flash 

evaporation system that justify its initial cost. First, 

because the solvent is reclaimed, the total amount 

consumed in mineral separation procedures is reduced 

substantially. Also, the recovered solvent is relatively 

uncontaminated and can be recycled in separations as 

"new" acetone. 

A second advantage is the elimination of large 

volumes of water in the recovery process and the 

accompanying loss of heavy liquids due to their 

solubility. Although the solubilities of these liquids 

are rather low (table 1), there will still be some loss. 

Water accelerates decomposition of heavy liquids. 

Lessening the exposure of a heavy liquid to water will 

increase the overall period of usefulness of the heavy 

liquid and will decrease the chance of creation of and 

exposure to harmful, toxic byproducts of 

decomposition. 

Bromoform that has been run through the flash 

evaporator will have a final specific gravity of 2. 7 5. 

Five to ten minutes in the water cascade system will 

return the density of the bromoform to its original 

value of 2.85. Even though there is some water 

exposure, this is still a greater than 92 percent 

decrease in the total amount of water that the heavy 

liquid is exposed to relative to the water cascade 

method when that is the sole recovery method. 

Because the evaporation process takes place in a 

closed system, there is less chance of atmospheric 

contamination. The safety hazards of heavy-liquid 

exposure have been previously documented. 

Detailed operating instructions are included in 

Appendix B of this report. 

Modifications to the standard unit 

Some modifications were made to the flashevaporation unit to increase the efficiency of the 

solvent recovery. The condensing coil was wrapped on 

the outside with tygon tubing and covered with 

insulating tape. Tapwater was then run through the 

outside hose as well as through the inside coils of the 

condenser. This procedure kept the spiral condenser 

cooler by insulating it from the warmer room air and 

thus speeded up the solvent recovery. A second 

modification (R. Tripp, oral commun., 1978) for 

enhancing the recovery is to run refrigerated water 
Condensing tube 

Drain for solvent 

Heating unit 

Solvent reservoir 

Water source 

Thermometer 

Evaporation flask 

Thermoregulator 

Figure 9.--Refluxing-distillation-condensing apparatus formerly used in the U.S. Geological Survey 

laboratory, Denver, Colorado. Photograph by Louise Hedricks. 

through the condenser. A pump circulating water from 

an ice bath not only conserves water, but greatly 

reduces the temperature of the condensing 

environment. 

Recovery and Stabilization of Heavy liquids 

The halogenated hydrocarbons are, by nature, 

unstable and will break down and darken in color with 

normal use. This decomposition is accelerated by 

exposure to heat, water, and ultraviolet radiation. The 

17 

darkening is caused by hydrolysis and the release of 

free halogens into the solution (Sax, 1968; Browning, 

1961). The following are recommended procedures for 

the reclamation of several common heavy liquids. 

These procedures have been empirically verified by the 

authors. 

BROMOFORM-Recovery and stabilization 

As bromform breaks down it releases free 

bromine (Brz) and hydrobromic acid (HBr) which can 
Spiral condenser coil 

Continuous-feed adapter 

Collecting flask 

Vacuum takeoff 

Spiral tubing and insulation 

Rotatable motor 

Thermoregulator 

Evaporator flask 

Heater 

Evaporating pan 

Figure 10.-Flash-evaporator apparatus used in the U.S. Geological Survey laboratory, Denver, 

Colorado. Photograph by Louise Hedricks. 

darken the solution to the point of opacity (Sax, 

1968). The reclamation procedures are as follows: 

1. Shake the darkened heavy liquid with a 5-10 

percent solution (approximately 20 percent 

by volume) of sodium hydroxide (NaOH) and 

let it stand for 24 hours. Sodium thiosulfate 

and sodium bicarbonate (5-10 percent 

solution) have also been suggested as 

possible substitutes for NaOH. These 

chemicals do an adequate job, are not as 

strong as the hydroxide base, and increase 

the longevity of the heavy liquid (R. Doll, 

oral commun., 1978). Be aware that sodium 

hydroxide is itself a hazard and should be 

treated with caution. 

18 

2. Put the mixture into a separatory funnel. 

Allow the bromoform and NaOH (or 

whatever solution is used) mixture to 

separate. Draw off the heavy liquid. 

3. Repeat the first two steps until the 

bromoform is transparent. 

4. Wash the heavy liquid in the water cascade 

system for 5 minutes. This will remove any 

solvent. 

5. Dry the bromoform by introducing several 

grams of calcium chloride (CaC12) per 100 

milliliters of heavy liquid; shake the mixture 

and allow it to set for several hours. This 

"dewatering" process will increase the 

density (Browning, 1961; Benjamin, 1971). 
6. Filter out the CaC12 and add 1-1.5 percent 

ethyl alcohol (Ijlst, 1973), or 0.05 percent 

propylene oxide (R. Doll, oral commun., 

1978) as a preservative. This will prevent 

the heavy liquid from darkening again 

prematurely. The preservative can be 

removed by washing with water and drying 

with CaC12• The slight loss in specific 

gravity (commonly from 2.89-2.85) is a small 

sacrifice relative to the increased longevity 

of the bromoform. A copper wire mesh can 

also be used as a stabilizing agent. 

However, this mesh is less effective and 

introduces metal contamination which can 

affect elemental analysis results. 

Bromoform that is removed directly from 

the evaporator, washed in the water cascade 

system, and which is not darkened by 

decomposition products can be directly 

stabilized without going through steps 1-5. 

METHYLENE IODIDE-Recovery and stabilization 

Methylene iodide is darkened by the presence of 

free iodine (Sax, 1968) giving a characteristic bloodred color. Due to hydrolysis (O'Connell, 1963), HI is 

formed in the solution. 

The reclamation process for MEI is similar to 

that of bromoform (Browning, 1961) with one 

exception. In stabilizing, instead of introducing 

chloroform or one of the other additives, a small 

amount of metallic copper or silver, in the form of 

wire mesh, is added to each bottle. Again, beware of 

contamination from the metals. (Ijlst, 1973; Cuttitta 

and others, 1960). 

An additional reclamation procedure is suggested 

by James Svoboda (written commun., 1979). Wash the 

discolored _MEI with a 5- to 10-percent solution of 

sodium sulfide, dry with calcium chloride, and stabilize 

with a small piece of copper or silver mesh. 

TETRABROMOETHANE-Recovery and stabilization 

The decomposition of this organic compound is 

similar to that of bromoform and the same 

reclamation methods can be utilized. 

An additional reclamation procedure, discussed 

in Patty (1962), is as follows: 

1. Wash the darkened solution three times with 

12 percent, by volume, concentrated H2so4 

and three times with water. 

2. Dry with potassium carbonate and calcium 

sulfate and filter. Specific amounts were 

not cited in the source references; however, 

several grams per 100 ml should be 

sufficient. (Potassium carbonate is 

considered a strong caustic with a moderate 

19 

rating for external exposure and ingestion 

(Sax, 197 5). The appropriate pr~cautions 

should be taken when using it.) 

CLERIC! COMPOUNDs-Recovery and stabilization 

Clerici solution, as previously described, is a 

mixture of thallium salts dissolved in distilled water. 

These salts can be recovered by evaporation in a sand 

or water bath. Either of these baths is recommended 

over evaporation on a hot plate as the temp ?.rature is 

more controllable in a bath. The evaporation process 

requires a controlled temperature because the salts 

will decompose if subjected to temperatures in excess 

of 130°C (Browning, 1961). The process of evaporation 

requires scrutiny as the salts can be decomposed if 

heated past the point of complete dryness (~~njamin, 

1971). 

Clerici solutions, however, are much m')re stable 

than the halogenated hydrocarbons but, if lef~ standing 

for a long period of time, a dark residue of 

decomposed thallium salts may form. This is 

reclaimed by the following procedure: 

1. Add a small amount of formic add to the 

solution and evaporate just to dryress. This 

will volatilize any remaining acid. 

2. Add distilled water to the dried compound 

and again evaporate. Do not overdry. 

(Browning, 1961.) 

FULLER'S EARTH RECLAMATION 

A method that is sometimes useful for organic 

heavy-liquid reclamation is to filter the liquid through 

fuller's earth or kaolin powder (Griffitts and 

Marranzino, 1960). The method is as follows: 

1. Shake a few grams of fuller's earth with 100 

ml of discolored heavy liquid. Pour the 

mixture into a separatory funnel and allow 

the residue to rise. 

2. Draw off the clear liquid and filter. A 

minimal amount of fuller's eartl must be 

used in order to avoid excessive hss of the 

heavy liquid by adsorption into the fuller's 

earth. A bonus is that the fuller's earth will 

preferentially absorb any water that happens 

to be present in the solution. The saturated 

powder should be discarded in a closed 

container. It cannot be reused. 

SELECTED REFERENCES 

Ahmed, A. F., Kubic, V. L., and Anders, M. W., 1977, 

Metabolism of haloforms to carbon mcnoxide; I. 

In vitro studies: Drug Metabolism and 

Disposition, v. 5, no. 2, p. 198-204. 
American Mutual Insurance Alliance, 1972, Handbook 

of organic industrial solvents (4th ed.): 

American Mutual Insurance Alliance, Technical 

Guide No. 6, 20 N. Wacker, Chicago, Til. 60607, 

76 p. 

__ 1977, Handbook of hazardous materials: American 

Mutual Insurance Alliance, Technical Guide No. 

7, 20 N. Wacker, Chicago, Til. 60607, 133 p. 

American National Red Cross, 1973, Advanced first 

aid and emergency care: Garden City, New 

York, Doubleday, 318 p. 

Anders, M. W., Stevens, J. L., Sprague, R. W., Shaath, 

Z., and Ahmed, A. F., 1978, Metabolism of 

haloforms to carbon monoxide; n. In vivo 

studies: Drug Metabolism and Disposition, v. 6, 

no. 5, p. 556-560. 

Benjamin, R. E. K., 1971, Recovery of heavy liquids 

from dilute solutions: American Mineralogist, v. 

56, no. 3-4, p. 613-619. 

Bowman, F., Borzelleca, J. F., and Munson, A. E., 

1978, The toxicity of some halomethanes in 

mice: Toxicology and Applied Pharmacology, v. 

44, no. 1, p. 213-216. 

Bunn, W. W., Haas, B. B., Deane, E. R., and Kleopfer, 

R. D., 1975, Formation of trihalomethanes by 

chlorination of surface water: Environmental 

Letters, v. 10, no. 3, p. 205-213. 

Browning, J. S., 1961, Heavy liquids and procedures for 

laboratory separation of minerals: U.S. Bureau 

of Mines Information Circular 8007, 14 p. 

Carver, R. E., 1971, Heavy-mineral separation, in 

Procedures in sedimentary petrology: New York, 

Wiley Interscience, p. 427-452.. 

Cole-Farmer Instrument Company, 1977, Plastic ware 

catalog: 7425 N. Oak Park Avenue, Chicago, Ill. 

60648, p. 253-304. 

Cuttitta, F., Meyrowitz, R., and Levin, B., 1960, 

Dimethyl sulfoxide, a new diluent for methylene 

iodide heavy liquid: American Mineralogist, v. 

45, nos. 5-6, p. 72.6-72.8. 

Engineered Materials, 1965, Heavy liquids brochure: 

P.O. Box 363, New York, New York 10008, 17 p. 

Griffitts, W. R., and Marranzino, A. P., 1960, Fuller's 

earth as an agent for purifying heavy organic 

liquids: Ame:rican Mineralogist, v. 45, nos. 5-6, 

p. 739-741. 

Horvath, A. L., 1976, Maximum permissible 

concentrations of halogenated hydrocarbons in 

reservoir waters-a review: London, Chemistry 

and Industry, v. 1, p. 26-27. 

Hutchison, C. S., 1974, Laboratory handbook of 

petrographic techniques: New York, John Wiley 

and Sons, 527 p. 

Ijlst, Lodewijk, 1973, New diluents in heavy liquid 

mineral separation and an improved method for 

the recovery of the liquids from the washings: 

American Mineralogist, v. 58, no. 11, p. 1084-

1087. 

zo 

Jahns, R. H., 1939, Clerici solution fo~ the specific 

gravity determination of small rrineral grains: 

American Mineralogist, v. 24, no. 2, p. 116-122. 

Kubic, V. L., and Anders, M. W., 1975, Metabolism of 

dihalomethanes to carbon monoxide; n. In vitro 

studies: Drug Metabolism and Disposition, v. 3, 

no. 2., p. 104-112. 

Kubic, V. L., Anders, M. W., Engel, R. R., Barlow, C. 

H., and Caughey, W. S., 1974, Metabolism of 

dihalometbanes to carbon monoxi1e; I. In vivo 

studies: Drug Metabolism and Dis:nosition, v. 2, 

no. 1, p. 53-57. 

Manufacturing Chemist Association, 1962, Chemical 

safety data sheet, SD-87-Acetone: 

Manufacturing Chemist Association, 1825 

Connecticut Avenue, Washington, J: .C. 20009. 

McElwee, Dennis J., 1979, Mineral research chemicals 

toxic properties-guidelines for proper handling 

(2nd ed.): Colorado School of M:nes Research 

Institute, 98 p. 

Muller, L. D., 1977, Laboratory methois of mineral 

separation, in J. Zussman, ed., Physical methods 

in determinative mineralogy: London, Academic 

Press, p. 8-12. 

National Biochemical Company, 1975,, Bromoform 

industrial safety data sheet: National 

Biochemical Company, Geoliquids Division, 3127 

W. Lake St., Chicago, Ill. 60612.. 

197 5, Methylene iodide: National Biochemical 

Company, Geoliquids Division Bulletin No. 31, 

312.7 W. Lake St., Chicago, Dl. 60612. 

National Fire Protection Association, 197 5, Hazardous 

chemical data: National Fire Protection 

Association No. 49, 310 p. 

National Safety Council, 1963, Data Sheet 398-

Acetone: 425 North Michigan Ave··me, Chicago, 

Ill. 

National Institute of Safety and Pealth, 1976, 

Suspected carcinogens (Zd ed.): National 

Institute of Safety and Health, Dept. Health, 

Education, and Welfare, 5600 Pshers Lane, 

Rockville, Md. 20857. 

1977, Registry of toxic effects of chemical 

substances: National Institute of Safety and 

Health, Dept. Health, Education, and Welfare, 

5600 Fishers Lane, Rockville, Md. 20857, p. 696. 

O'Connell, W. L., 1963, Properties of l'~avy liquids: 

Transamerican Institute of Mining, Metallurgical 

and Petroleum Engineering, v. 22.9, p. 12.6-132. 

Patty, F. A., 1962, Industrial hygiene arJd toxicology: 

New York, Interscience Publishers, v. 2, p. 831-

2377. 

Rosenblum, Sam, 1974, A mineral separation procedure 

using hot clerici solution: U.S. Geok>gical Survey 

Journal of Research, v. 2, no. 4, p. 479-481. 

Sax, N. I., 1968, Dangerous properties of industrial 

materials (3rd ed.): New York, Van Nostrand 

Reinhold, 1251 p. 
__ 197 5, Dangerous properties of industrial materials 

(4th ed.): New York, Van Nostrand Reinhold, 

1258 p. 

Simmer, V. F., 1977, Structural correlations of 

carcinogenic and mutagenic allyl halides, in 

Asher, I. M., and Zervos, C., eds., Structural 

correlates of carcinogenesis and mutagenesis: 

Food and Drug Administration Office of Science, 

Summer Symposium, 2d, Proceedings, p. 163-171. 

Simmon, V. F., Kauhanen, K., and Tardiff, R. G., 1977, 

Mutagenic activity of chemicals identified in 

drinking water: Developments in Toxicology and 

Environmental Science, v. 2, p. 249-258. 

Stevens, J. L., and Anders, M. W., 1978, Studies on the 

mechanism of the metabolism of haloforms to 

carbon monoxide: Toxicology and Applied 

Pharmacology, v. 45, no. 1, p. 297. 

Zl 

Sullivan, J. D., 1927, Heavy liquids for mineral 

analysis: U.S. Bureau of Mines Technical Paper 

381, p. 10-25. 

Theiss, J. C., Stoner, G. D., Shimkin, M. B., and 

Weisburger, E. K., 1977, Test for carcirogenicity 

of organic contaminants of Unitei States 

drinking waters by pulmonary tumor response in 

strain A mice: Cancer Research, v. 37, no. 8, pt. 

1, p. 2717-2720. 

Vassar, Helen E., 1925, Clerici solution fo~ mineral 

separation by gravity: American Mineralogist, v. 

10, no. 5, p. 123-125. 

Weast, R. C., ed., 1970, Handbook of cheiristry and 

physics (50th ed.): The Chemical Rubber 

Company. 

Zussman, J., 1977, Physical methods in determinative 

mineralogy: London, Academic Press, 720 p. 

• 
APPENDIX A 

Properties of Some Less-Common Dilutants 

The following solvents are suggested by various sources as possible dilutants for specialize-l heavy liquids. 

Upon closer examination of their properties, however, it becomes apparent that, in general, they are more toxic 

than acetone and less easy to handle. Great caution is advised in their use. 

BENZENE (benzol, phenyl hydride) 

Chemistry: C6H6 

Physical properties: 

Description: 

Molecular weight: 

Flash point: 

Density: 

Source references: 

Colorless liquid. 

78-1 

6°C 

0.879 at Z0°C 

Sax (1978); McElwee, 

(1979). 

Toxicity 

TL V 10 ppm, considered highly toxic. 

Exposure 

Benzene can easily penetrate the skin, inducing a 

high amount of irritation. 

Heavy exposure can cause respiratory paralysis, 

narcosis, and failure of the central nervous system. 

Benzene is a carcinogen of the blood-forming tissues, 

and repeated blood examination is necessary for those 

who may have been exposed. 

Hazards 

Benzene is highly flammable, and reacts 

vigorously with oxidizing agents. Adequate ventilation 

is imperative. 

CARBON TETRACHLORIDE (tetrachloromethane, 

perchloromethane) 

Chemistry: 

Physical properties: 

Description: 

Molecular weight: 

Boiling point: 

Flash point: 

Density: 

Source reference: 

CC14 

Colorless liquid. 

153.8 

76.8°C 

None. 

1.597 at Z0°C 

Sax (1978). 

Toxicity 

TLV 10 ppm, considered highly toxic. 

Exposure 

The initial sign of exposure is gastronomic 

upset. CC14 has a narcotic reaction, having markedly 

varying individual susceptibility. Repeated exposure 

can cause severe liver, kidney, and lung damage. 

Heavy exposure may result in death due to respiratory 

failure. 

zz 

Hazards 

Carbon tetrachloride is nonflammc.ble; however, 

if it is heated to decomposition, it emits flammable 

and toxic fumes of phosgene. 

DIMETHYL SULFOXIDE (DMSO) 

Chemistry: (CH3)

2so 

Physical properties: 

Description: 

Molecular weight: 

Melting point: 

Flash point: 

Density: 

Source references: 

Clear, water-white, 

hygroscopic liquid. 

78.1 

18.5°C 

189°C 

1.100 at Z0°C 

Sax (197,'~); Zussman 

(1977). 

Toxicity 

TL V not assigned. 

Exposure 

Dim ethyl sulfoxide freely penetrates the skin, 

causing redness, burning, and general irritation. 

Systematic exposure can cause chills, nausea, and 

cramps. In some cases, an anaphylactic or allergic 

reaction may take place. In laboratory 

experimentation it has caused corneal opa--:ity. 

Hazards 

DMSO is moderately flammable, ard may react 

vigorously with oxidizing materials. 

ISOAMYLACETATE (amyl acetate, beman.-.. oil) 

Chemistry: CH3COO(C5H11) 

Physical properties: 

Molecular weight: 

Boiling point: 

Flash point: 

Density: 

Source reference: 

130.2 

14Z.0°C 

10.7°C 

0.876 

Sax (1978). 

Toxici~ 

TLV 50 ppm or 700 mg/m air. 

Exposure 

Exposure to more than 1,000 ppm in an hour 

results in the following symptoms: heada~he, fatigue, 

pulmonary irritation. 
Hazards Source references: Sax (1978); Zussman 

Isoamylacetate is highly flammable, and may 

react vigorously with reducing materials. 

N,N-DIMETHYL FORMAMIDE (DMF, N,N dimethyl 

formic acid) 

Chemistry: (CH3)

2NHCO 

Physical properties: 

Description: 

Molecular weight: 

Boiling point: 

Density: 

Source references: 

Colorless, mobile liquid, 

(fishy odor). 

73.1 

152.8°C 

0.9445 

Sax (1978); American 

Mutual Insurance 

Alliance (1972); 

McElwee (1979). 

Toxicity 

Assigned TLVof 10 ppm. 

Exposure 

DMF is extremely irritating, and can be absorbed 

through the skin. A fishy odor may warn of 

overexposure, with symptoms being: itching, nausea, 

and loss of equilibrium. Prolonged inhalation may 

cause liver and kidney damage. 

Hazards 

DMF is moderately flammable, and can be 

extinguished by dry chemical or co2 fire 

extinguishers. According to Sax (1978), contact with 

DMF and halogenated hydrocarbons and inorganic 

nitrates should be avoided. 

ORTHODICHLOROBENZENE (a-dichlorobenzene) 

Chemistry: C6H4c12 

Physical properties: 

Description: 

Molecular weight: 

Melting point: 

Boiling point: 

Flash point: 

Density: 

Clear liquid. 

140.0 

-17.5°C 

180-183°C 

52°C 

1.307 at 20°C 

(1977); American 

Mutual Insurance 

Alliance (1 ?72). 

Toxicity 

The TLV set by the ACGIH is 50 ppm. 

Exposure 

Orthodichlorobenzene is highly narc?tic, with 

overexposure causing cyanosis, rapid breath~.ng and, in 

more extreme cases, kidney and liver failure. It is also 

an irritant to the skin and mucous membranes, with 

slight exposure causing nasal and eye irritation. 

Hazards 

Orthodichlorobenzene is moderately flammable, 

and may react vigorously with oxidizing materials. 

TRIETHYLORTHOPHOSPHATE (triethyl p~hate, 

TEP) 

Chemistry: 

Physical properties: 

Description: 

Molecular weight: 

Melting point: 

Boiling point: 

Flash point: 

Weight per gal: 

Density: 

Source reference: 

Colorless 

completely 

in water. 

182.2 

-56.4°C 

216°C 

101.2°C 

8.9 lbs 

1.067 

Sax (1978). 

Toxicity 

liquid, 

miscible 

The toxicity is unknown, but this substance 

should be considered hazardous until proved otherwise. 

Exposure 

Exposure may cause nerve injury, R"ld TEP is 

known to be a cholinestrase inhibitor. 

Hazards 

23 

TEP is labeled a poison. It is slightly flammable, 

and may react vigorously with oxidizing materials. 
APPENDIX B 

Procedure for the use of a Buchler Flash 

Evaporator Model PTFE-1gn 

1. Check the stability of the apparatus. Make sure 

all holding clamps are tight. The glassware 

components are extremely expensive! 

2. Seal all the glass joints with stopcock grease. 

This will greatly improve the efficiency of the 

vacuum. 

3. Fill the evaporating pan approximately half full 

of water and submerge the heating coil. Never 

apply voltage to the coil unless it is immersed in 

water. 

4. Fill the evaporating flask with approximately 

1,000 ml of solvent-heavy liquid mixture and 

assemble it on the apparatus. Be sure to check 

all glassware for flaws, stars, or cracks. 

Applying a vacuum to a damaged flask could 

result in an implosion. 

5. Put the condensing flask on the spiral 

condenser. Support it with a Thomas clamp and 

a ring stand. As evaporation takes place the 

balance of the unit will be shifted to the 

condenser side, necessitating this additional 

support. 

6. Close the vacuum release valve and the 

continuous-feed stopcocks and apply a vacuum. 

A closed vacuum pump seems to give the best 

results. A water aspirator system was 

experimented with but a loss of solvent and 

accidental, but consistent, introduction of water 

into the system occurred. 

7. Turn on and adjust the thermoregulator to the 

desired temperature. A temperature between 

35° and 40°C is recommended, but most 

efficient results may be obtained by 

experimenting with different temperatures. The 

optimum temperature may vary with instrument 

and environment. 

8. Turn on the water to the spiral condenser. 

Adjusting the water pressure slowly will allow 

time to check all connections. 

24 

9. Start the rotatable motor. Make a second 

examination to be sure that all th~ glass joints 

are sealed and secure. 

10. Continue evaporation until all of t:t.-e solvent has 

been removed; this is indicated 1:-~r no further 

condensation in the spiral condensf!r. The time 

required will depend on the heavy liquid to 

solvent ratio, but should be no greater than 30 

minutes per 1,000 mi. 

11. To shut off the evaporator: 

a. turn off the thermoregulator, 

b. turn off the rotatable motor, 

c. shut off the water, 

d. turn off the vacuum pump, ar.d 

e. release the vacuum. 

12. Remove the reclaimed solvent and store it. The 

density should be checked. H it is too high, the 

solution may need to be re-evaporated at room 

temperature to complete purificaticn. A density 

greater than 0.88 for the acetone is an indication 

of the presence of heavy liquid as a contaminate. 

13. Remove the heavy liquid and store it in a dark, 

glass container. See Section m for reclamation 

and stabilization procedures. 

14. CLEAN UP THE WORK AREA!!! 

Although this system is relative!;• safe, some 

simple precautions will reduce the chanc~ of accident 

and injury. 

Be sure the system is under a properly 

ventilating hood. The chance of expos,lre to fumes 

will be greatly reduced and, in the event of an 

implosion, the debris will be contained, as will any 

solvent or heavy liquid released. 

Wear proper, protective laboratorr gear. The 

use of safety goggles, rubber apron, and r•.tbber gloves, 

will greatly reduce the chance of perso""lal injury or 

exposure. Cloth and plastic aprons or coats are not 

recommended. Cloth is permeable to hea'"Y liquids and 

many plastics deteriorate with exposure. 

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