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Lindane

DESIGNATIONS

CAS No.: 58-89-9
Registry name: Lindane
Chemical name: g -Hexachlorocyclohexane
Synonyms, Trade names: Lindane, gamma-BHC, benzene hexachloride, g -HCH, Hortex, Cortilan, Jacutin Fog; known under at least 80 different tradenames (also in mixtures with other agents); a list of trade names is found in: INDUSTRIEVERBAND PFLANZENSCHUTZ e.V., 1982)
Chemical name (German): Lindan, g -Hexachlorcyclohexan, Hexachlorcyclobenzol
Chemical name (French): Lindane, hexachlorure de benzne
Appearance: colourless, odourless crystals

BASIC CHEMICAL AND PHYSICAL DATA

Empirical formula: C6H6Cl6
Rel. molecular mass: 290.83 g
Density: 1.85-1.90 g/cm3
Relative gas density: 10
Boiling point: 323.4C (decomposition)
Melting point: 112.5C
Vapour pressure: 0.94 x 10-5 Pa at 40C, 1300 Pa at 176.2C
Solvolysis/solubility: in water 7.3 - 7.8 mg/l at 20C
in benzene 289 g/l at 20C
in diethylether 208 g/l at 20C
in acetone 435 g/l at 20C
readily soluble in ethanol and chloroform
Conversion factors: 1 ppm = 12.1 mg/m3
1 mg/m3 = 0.083 ppm

ORIGIN AND USE

Usage:
Lindane is an insecticide used to combat biting and sucking species in the fruit-growing, horticultural and agricultural sectors as well as in forestry. It is also used to combat pests in empty food storage tanks and is used in human and veterinary hygiene.

Origin/derivation:
Technical production by photochlorination of benzene which yields a mixture of HCH isomers from which the individual isomers can be extracted. The gamma-HCH content of the mixture is between 10 - 18%. Some 80 - 90% unwanted isomers are produced in the first step. The maximum purity is 99%; 1% are other isomers.

Production figures:

Germany: 1,500 t (1977)
250 t (1982)
< 1,000 t (1985)
Worldwide: 5,000 t (1983) plus 23,000 t in technical HCH


Toxicity

Humans: LD100 150 mg/kg acc. UBA 1981, Ber. 10704006/1
10-20 mg/kg (acute toxicity) acc. UBA, 1981, Ber. 10704006/1
Mammals:
Rat LD50 88-125 mg/kg, oral acc. CEC, 1981
LD50 125-230 mg/kg, oral acc. CEC, 1981
LD50 500 mg/kg, dermal acc. IPS, 1982
LD50 >10,000 mg/kg, dermal acc. RIPPEN, 1991
NEL 1.25 mg/(kgd) VETTORAZZI, 1979
Mouse LD50 86 mg/kg, oral acc. CEC, 1981
LD50 245-480 mg/kg, oral acc. IPS, 1982
Dog LD50 40 - 200 mg/kg, oral acc. CEC, 1981)
NEL 1.6 mg/(kgd) VETTORAZZI, 1979
Aquatic organisms:
Leuciscus idus melanotus LC0 0.05/0.02 mg/l (48h) Juhnke & LDEMANN, 1978
LC50 0.28/0.003 mg/l (48h) JUHNKE & LDEMANN, 1978
LC100 0.5/0.07 mg/l (48h) JUHNKE & LDEMANN, 1978
Brachydanio rerio LC0 0.07 mg/l (48h) acc. UBA, 1981, Ber. 10704006/1
LC50 0.06/0.09 mg/l (48h) acc. UBA, 1981, Ber. 10704006/1
Golden orfe LC50 0.03-0.25 mg/l acc. ROTH, 1988
Carp LC50 0.28 mg/l acc. LOUB, 1975
Brown trout (Salmo trutta) LC50 0.0017 mg/l (96h, 13C) acc. DVWK, 1985
Lebistes LC0 1.3 mg/l (96h) acc. ROTH, 1988
Water flea (Daphnia magna) EC0 0.02 mg/l (24h) acc. UBA, 1981, Ber. 10704006/1
EC50 0.7 mg/l (24h) acc. UBA, 1981, Ber. 10704006/1
EC100 7.0 mg/l (24h) acc. UBA, 1981, Ber. 10704006/1
Green algae EC50 1.7-3.8 mg/l (96h) acc. UBA, 1981, Ber. 10704006/1
Green algae (Chlorella spec.) EC50 0.2-0.3 mg/l (96h) acc. UBA, 1981, Ber. 10704006/1

Characteristic effects:

Humans/mammals: A carcinogenic substance (acc. ROTH, 1989) which causes nausea, vomiting, unrest and spasms. It has a harmful effect on the liver and kidneys and can impair the central nervous system in humans.

Insects: Respiratory poison; toxic for bees.

Plants: Alteration of cell structure, damage to roots, inhibition of growth, problems with respiration.

ENVIRONMENTAL BEHAVIOUR

Water:
More than 90% of lindane in surface and groundwater is found in dissolved form; little is adsorbed on sediment and suspensions (acc. DVGW, 1988); accumulation in organisms; contamination of groundwater in immediate vicinity of dumps and in sewage-water seepage areas.

Air:
Transport medium; estimated deposition in Germany (West) 6-60 t/a (SRU, 1980).

Soil:
Accumulation; in some cases it is an extremely stable chemical which is still present after 11 to 14 years (SIEPER, 1972; LOUB, 1975; KORTE, 1980) depending on the type of soil, content of humic substances, moisture, dosage and combination with other agents. Applied quantities of 0.1 - 1 kg/ha are subject to between 40 and 80% decomposition after roughly one year. Reduction of soil flora; hazardous to groundwater mostly in sandy soils (DVGW, 1988).

Half-life:
Soil: 8-18 months (UBA, 1986), 200-260 days (RIPPEN, 1991); surface water or groundwater: 7 months - 4 years (UBA, 1986); 15-20 weeks (DVGW, 1988).

Degradation, decomposition products:
By way of dehydrochlorination, dehydrogenation and dechlorination; degradation via hexachlorocyclohexene, pentachlorocyclohexene and tetrachlorocyclohexene to form primarily chlorinated benzenes and phenols; usually due to microorganisms under both aerobic and anaerobic conditions; particularly stable in acid milieu; abiotic degradation through photomineralisation to form CO2; above 230 nm transformation of gamma-isomer to alpha-isomer; degradation in soil takes place in several stages; initially physical effects such as surface volatilisation, evaporation or condensation with water, elution into deeper soil layers and diffusion, then biological degradation.

Food chain:
Considerable variation in assessment of human intake: US-EPA (1980) = 70% drinking water, 30% fish, air negligible; DFG (1982) = air and drinking water < 1%, primarily in animal-based foodstuffs; accumulation in mother's milk (HAHNE et al. 1986).

ENVIRONMENTAL STANDARDS

Medium/ acceptor Sector Country/ organ. Status Value Cat. Remarks Source
Water: Drinkw A

(G)

3 g/l     acc. DVGW, 1988
Drinkw CDN

(L)

4 g/l     acc. DVGW, 1988
Drinkw D

L

0.1 g/l     TVO, 1990
Drinkw DDR

(L)

20 g/l     acc. DVGW, 1988
Drinkw USA

(L)

4 g/l     EPA, 1975
Drinkw USA

G

0.2 g/l     EPA, 1986
Drinkw WHO

G

3 g/l     WHO, 1984
Groundw USA

G

0.005 mg/l   State of Illinois acc. WAITE, 1984
Surface 1)   0.1 g/l   2) IAWR, 1986
Surface 1)   0.5 g/l   3) IAWR, 1986
Surface D

G

1.4 g/l   2) DVWG, 1988
Surface D

G

6.8 g/l   3) DVWG, 1988
Surface USA

G

0.005 mg/l   State of Illinois acc. WAITE, 1984
Surface USA

G

0.01 g/l   Prot. of aquat. org. EPA, 1976
Soil:   NL

L

2 mg/kg   Intervention acc. TERRA TECH, 6/94
Air:
  DDR

(L)

0.03 mg/m3 (MIK) 30 min acc. STERN, 1986
  DDR

(L)

0.01 mg/m3 (MIK) 24 h acc. STERN. 1986
Workp D

L

0.5 mg/m3 MAK   acc. DFG, 1994
Workp DDR

(L)

0.5 mg/m3 (MAK) Short-time value acc. HORN et al., 1989
Workp DDR

(L)

0.2 mg/m3 (MAK) Long-time value acc. HORN et al., 1989
Workp USA

(L)

0.5 mg/m3 TWA   ACGIH, 1986
Workp D

L

0.02 mg/l BAT Whole blood DFG, 1994
Workp D

L

0.025 mg/l BAT Plasma/serum DFG, 1994
Foodstuffs:4)   D

G

12.5 g/(kg.d) ADI   WHO/FAO, 1973
    WHO

G

10 g/(kg.d) ADI   WHO/FAO, 1984
Potatoes   D

L

0.1 mg/kg     acc. DVGW, 1988
Grain   D

L

0.1 mg/kg     acc. DVGW, 1988
Tea   D

L

0.5 mg/kg     acc. DVGW, 1988
Vegetables   D

L

1.5 mg/kg     acc. DVGW, 1988
Green veg.   D

L

2 mg/kg     acc. DVGW, 1988
Fat5)   D

L

0.1 mg/kg     acc. DVGW, 1988
Fat6)   D

L

0.2 mg/kg     acc. DVGW, 1988
Milk   D

L

0.7 mg/kg     acc. DVGW, 1988
Eggs   D

L

2 mg/kg     acc. DVGW, 1988

Notes:

1) Countries bordering the Rhine
2) Limit value when using natural purification methods for drinking water treatment
3) Limit value when using physical and chemical purification methods for drinking water treatment
4) Limit values as per Order Governing Maximum Quantities of Pesticide (1984) referenced to human foodstuffs
5) In fish and meat
6) In poultry
The use of technical HCH is banned in the Federal Republic of Germany.

Comparison/reference values

Medium/origin Country Value Source
Lake Constance D 0.005 mg/l acc. DVGW, 1988
Rhine (Karlsruhe) D 0.05-0.5 mg/l acc. DVGW, 1988
Danube (Passau) D 0.001-0.04 mg/l acc. DVWK, 1985
Elbe D 0.003-0.123 mg/l acc. DVWK, 1985
Rivers/lakes (Mississippi) USA 0.02-0.16 mg/l acc. DVWK, 1985
Rivers J 0.01-0.1 mg/l acc. DVWK, 1985
Lake Mariot ET 0.14-7.7 mg/l acc. DVWK, 1985

Assessment/comments

Legal regulations often treat all hexachlorocyclohexane isomers as a substance group and thus give total figures. Approximate values for surface water or groundwater often refer not to single compounds but to pesticides as a substance class. According to DVGW (1988), technical HCH is banned in most European countries and in North America but, however, is used in many Third-World countries. It is estimated that all lindane produced is released into the environment. The amount worldwide may be 38,000 t/a. The high persistence and accumulation in the fatty tissue of humans and mammals is a good reason to further reduce its application.

Special sources: INDUSTRIEVERBAND PFLANZENSCHUTZ e.V., 1980


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