1. Carbon disulfide -overview
• By
• Dr.Ashok laddha
• Occupational Health
Physician
• MBBS, PGDC
,PGDD, PGDEM, AFIH
,ACLS,BLS
• Diploma in Workplace
Health and safety. MBAHA(In –Progress)

2. Overview
• Carbon disulfide (CS2) in its pure form is a
colourless, volatile and in-flammable liquid with a sweet
aromatic odour.
• The technical product is a yellowish liquid with a
disagreeable odour.
• Odour-Like choloroform in pure form and foul in
commercial form
• Melting point—110.8 degree C
• Boiling point---46.3 degree C
• soluble in alcohol, ether, benzene, oil. chloroform, CCl
• IUPCA Name---Methanedithione
• Vapours are explosive

3. Origin of the substance
• Carbon disulfide was formerly manufactured
by direct reaction of sulphur vapour and coke
in iron or steel retorts at 750 - 1000°C
but, since the early 1950's, the preferred
method of synthesis has been the catalyzed
reaction between sulphur and methane: 600°
• CH4 + S CS2 + 2H2S
• SiO2.gel
or
Al2O3
(Greenwood
&
Earnshaw, 1984)

4. Sources-1
• Carbon disulfide is used in large quantities as an industrial chemical for
the production of viscose rayon fibres. In this technological process, for
every kilogram of viscose produced, about 20-30 g of carbon disulfide and
4-6 g of hydrogen sulfide are emitted .
• Additional release of carbon disulfide, carbonyl sulfide and hydrogen
sulfide takes place from coal gasification plants
• The ventilation discharge from viscose plants can reach several millions of
m3 per hour, with a carbon disulfide content varying from 20 to 240
mg/m3, which represents a total emission of 15-40 tonnes of carbon
disulfide daily
• it is also used in the production of carbon tetrachloride and cellophane.
• Carbon disulfide is used as a solvent for rubber, sulfur, oils, resins, and
waxes, and has been used for soil fumigation and insect control in stored
grain. Industrial processes that produce carbon disulfide as a by-product
include coal blast furnaces and oil refining.

5. Sources-2
• Other sources include animal waste, in
particular pig urine and faeces, fish
processing, plastic and refuse combustion,
synthetic fibre and starch manufacture,
turbines, natural gas and

6. Risk grp
• Those engaged in technological processes in
the viscose industry.
• The general population living near viscose
plants may also be exposed to carbon
disulfide emissions.
• Young woman

7. Biotransformation-1
• The metabolism of carbon disulfide is basically performed
by two main pathways:
• Reaction with amino acids and protein (glutathione) and via
the microsomal cytochrome P-450 monooxygenase system
.
• Amino acids of blood plasma react with carbon disulfide,
forming dithiocarbamic acid and a cyclic compound of the
thiazolinone type. The “free” carbon disulfide present in
the blood is distributed to various tissues and organs,
where it reacts with endogenous amines to form acid-labile
metabolites (dithiocarbamates and 2-thio-5-thiazolidinone)
excreted in the urine. Dithiocarbamate metabolites are
potential chelating agents.

8. Biotransformation-2
• A part of the carbondisulfide is bound to glutathione (GSH), forming
thiazolidine-2-thione-4-carboxylic acid and then 2-oxythiazolidine-4carboxylic acid, which is excreted in the urine.
• The other metabolic pathway involves the microsomal cytochrome P-450
monooxygenase system catalyzing the oxidative desulfuration of carbon
disulfide to an unstable oxygen intermediate. The intermediate
spontaneously degrades to atomic sulfur and carbonyl sulfide or
undergoes attack by water, forming atomic sulfur and
monothiocarbamate. Carbonyl sulfide is oxidized to atomic sulfur and
carbon dioxide .The atomic sulfur liberated in these reactions can be
covalently bound to the macromolecules or be oxidized to sulfate and
excreted in urine. Formed carbonyl sulfide can be catalyzed by carbonic
anhydrase to monothiocarbamate, which is spontaneously degraded to
carbon dioxide and HS-.
• The HS-is oxidized to sulfate or other still unknown metabolites.
• Monothiocarbamate can enter the urea cycle, forming thiourea, which is
excreted in urine

9. elimination
• The elimination of carbon disulfide via exhaled air takes
place in a typical three-phase process: rapidly from the
respiratory tract, more slowly from the blood and very
slowly from tissues and organs .
• A small quantity (about 1%) of unchanged carbon disulfide
is excreted via the urine, saliva and faeces.
• The excretion of the “free” carbon disulfide through the
skin is about three times greater than that via the urine.
• The majority of metabolized carbon disulfide is excreted in
the form of “ethereal sulfates” and the other part in the
form of the metabolites mentioned earlier .

10. Health effect
• Acute exposure effect
• Sub acute
• Chronic exposure effect

11. Routes of exposure
• Skin
• Inhalation
• Ingestion

12. Health effect-1
• Acute and subacute poisoning appear due to
exposure to carbon disulfide concentrations of
500-3000 mg/m3
• characterized by predominantly neurological and
psychiatric
symptoms,
“encephalopathia
sulfocarbonica” such as irritability, anger, mood
changes,
manic
delirium
and
hallucinations,
paranoic
ideas,
loss
of
appetite, gastrointestinal disturbances and sexual
disorders

13. Health effect-2
• More subtle neurological changes at lower carbon
disulfide concentrations have been reported; the
symptoms are a reduction of nerve conduction
velocities and psychological Disturbances .
• In workers exposed for 10-15 years to carbon disulfide
in concentrations of around 10 mg/m3, sensory
polyneuritis and increased pain threshold were
reported .
• These neurological disturbances were accompanied by
psychological and neurobehavioural disorders .

14. Health effect-3
• At an exposure of between 100 and 500
mg/m3 carbon disulfide has neurological,
vascular and other effects on the eye: focal
haemorrhage, exudative changes, optic
atrophy, retrobulbar neuritis, microaneurisms
and vascular sclerosis
• “microangiopathia sulfocarbonica” is reported
in young Japanese and Yugoslav workers

15. Health effect-4
• In chronic exposure to medium and lower carbon
disulfide concentrations (20-300 mg/m3), the effects
of carbon disulfide on blood vessels in various organs
and tissues,
• especially cerebral and renal arteries, producing
encephalopathy and nephropathy, are well
established

16. Health effect-5
• occupational exposure to carbon disulfide can cause
coronary heart disease (CHD), even at lower exposures
(30-120 mg/m3)
• Chronic exposure to carbon disulfide concentrations of
50-150 mg/m3affected the endocrine system by causing
decreased excretion of some hormones in the urine of
young exposed workers
• Decreased thyroxine levels
• hypospermia, asthenospermia and teratospermia in
young workers exposed to 40-80 mg/m3 of carbon
disulfide

17. Health effect in Female
• Menstrual Ir-regularities
• Spontaneous abortion
• Pre-mature deliveries

18. Effect of Acute poisoning
• Exposure to about 10 g/m3 may cause coma or
even death due to respiratory failure and
convulsion
• Acute toxic effects include central nervous system
depression,
peripheral
neuropathy
and
cardiovascular
collapse.
Dyspnoea
and
respiratory failure may occur following exposure
to high concentration. Carbon disulphide is
irritant to eyes and skin and may cause corneal
erosions and chemical burns respectively.

19. Predisposing Conditions for Carbon
Disulfide Toxicity-1
• Persons with disorders of the central nervous
system, eyes, cardiovascular system, kidneys, and liver
may be more sensitive to CS2
• Persons taking disulfiram (Antabuse) may be more
sensitive to CS2 since disulfiram is metabolized to cs2
• In
persons
using
drugs
such
as
analgesics,
hypnotics,
antidiabetics,
and
anticonvulsants, which are metabolized by oxidative Ndemethylation, critical elevations in the plasma levels
of these agents may be observed following exposure to
CS2. Persons exposed to other neurotoxicants may be
at increased risk during carbon disulfide exposure .

20. Predisposing Conditions for Carbon
Disulfide Toxicity-2
•
•
•
•
Peptic ulcer
Gastritis
Chronic gastro-intestinal diseases
Pulmonary conditions that prevents the use of
respirators
• Positive iodine- azide test in pre workshift
urine sample

21. Odour Nuisance
• It seems unlikely that carbon disulfide in missions from
the viscose industry is the major contributor to odour
nuisance. Probably, the nuisance caused by viscose
odours is mainly due to hydrogen sulfide and carbonyl
sulfide; therefore, it occurs at concentrations below
the carbon disulfide odour detection threshold of 200
μg/
• Carbon disulfide present in air could be partially
decomposed by light. Oxidation leads to the formation
of carbonyl sulfide, sulfur dioxide and carbon
monoxide . Carbonyl sulfide in particular causes an
unpleasant odour.

22. Assessment of exposure
• Environmental-Gas detection tube,
photmetric analysis, Gas analyzer, Gas liquid
chromatograpy
• Biological-Iodine –azide test

23. Health examination
• Pre-placement medical examination
• Periodical medical examination

24. Pre-placement medical examination
• Medical History
• Physical and clinical examination
• Special attention to nervous and cardiovascular
system
• ECG
• exercise TEST
• Lipid profile
• Ophthalmoscopy to detect possible retinopathy

25. Periodical medical examination
•
•
•
•
•
•
•
•
•
•
•
6 monthly
CBC
Lipid profile, Renal profile, Liver profile
Eye examination-fundoscopy
EMG
EEG
Behavioral testing
Measurement of nerve conduction velocity
Color discrimination testing
Blood glucose tolerance
Thyroid function test

26. Control Measures
•
•
•
•
•
•
Process enclosure
General and local ventilation
Sound work practice
Use of PPE--High standard of personal hygiene
Should maintain high quality of industrial
hygiene

27. Workplace standards
• The threshold limit value (TLV) -Occupational
Safety and Health recommends a level of 1
ppm.
• MAC level recommended by group of WHO
experts: 60 mg/m3 (no more than 15
minutes). MAC (men workers) 10 mg/m3
(ppm) MAC (women workers) 3 mg/m3 (ppm)