Methidathion (ISO) Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSE KRISTALLE
CHEMISCHE GEFAHREN
Die Substanz zersetzt sich beim Erhitzen unter Entstehung giftiger Rauche.
ARBEITSPLATZGRENZWERTE
TLV nicht festgelegt.
MAK nicht festgelegt.
AUFNAHMEWEGE
Aufnahme in den Körper in gefährlichen Mengen durch Inhalation, über die Haut und durch Verschlucken.
INHALATIONSGEFAHREN
Eine gesundheitsschädliche Partikelkonzentration in der Luft kann schnell erreicht werden beim Dispergieren.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Cholinesterasehemmer. Möglich sind Auswirkungen auf das Nervensystem mit nachfolgenden Krämpfen und Atemdepression. Exposition kann zum Tod führen. Die Auswirkungen treten u.U. verzögert ein. ärztliche Beobachtung notwendig.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Cholinesterasehemmer. Kumulative Wirkung möglich (s. AKUTE GEFAHREN/SYMPTOME).
LECKAGE
Persönliche Schutzausrüstung: Vollschutzanzug mit umgebungsluftunabhängigem Atemschutzgerät. NICHT in die Umwelt gelangen lassen. Verschüttetes Material in abdichtbarenBehältern sammeln. Reste sorgfältig sammeln. An sicheren Ort bringen.
R-Sätze Betriebsanweisung:
R21:Gesundheitsschädlich bei Berührung mit der Haut.
R28:Sehr giftig beim Verschlucken.
R50/53:Sehr giftig für Wasserorganismen, kann in Gewässern längerfristig schädliche Wirkungen haben.
S-Sätze Betriebsanweisung:
S22:Staub nicht einatmen.
S28:Bei Berührung mit der Haut sofort abwaschen mit viel . . . (vom Hersteller anzugeben).
S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
S60:Dieses Produkt und sein Behälter sind als gefährlicher Abfall zu entsorgen.
S61:Freisetzung in die Umwelt vermeiden. Besondere Anweisungen einholen/Sicherheitsdatenblatt zu Rate ziehen.
Beschreibung
Methidation is used as an insecticide. Cross-sensitivity
was described to dichlorvos.
Chemische Eigenschaften
Methidathion is a colorless crystalline pesticide at room temperature. It is sparingly soluble in water, but very soluble in octanol, ethanol, xylene, acetone, and cyclohexane. Methidathion is a non-systemic organophosphorous insecticide and acaricide with stomach and contact action. It is used to control a variety of insects and mites on crops and fruit plants. Methidathion is highly toxic to animals and humans. The US EPA grouped methidathion as a class I toxic substance and as an RUP.
Verwenden
Methidathion is an organophosphate insecticide and was examined for human health and toxicological concerns.
Allgemeine Beschreibung
Methidathion is a colourless crystalline pesticide at room temperature. It is sparingly soluble in water but very soluble in octanol, ethanol, xylene, acetone, and cyclohexane.
Air & Water Reaktionen
Stable in neutral or weak acid solution. Hydrolyzed by alkali. [EPA, 1998].
Reaktivität anzeigen
Organophosphates, such as Methidathion, are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.
Hazard
Toxic by ingestion, a cholinesterase
inhibitor.
Health Hazard
Methidathion is poisonous to humans. Its toxic effects are by action on the nervous system. Human volunteers ingesting 0.11 mg/kg/day for 6 weeks had no clinical effects.
Brandgefahr
(Non-Specific -- Organophosphorus Pesticide, n.o.s.) Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. Stable in neutral or weak acid solution. Hydrolyzed by alkali.
Landwirtschaftliche Anwendung
Insecticide: A U.S. EPA restricted Use Pesticide (RUP). Not approved for use in EU countries
. There are no residential
uses for methidathion. Methidathion is a non-systemic organophosphate insecticide and acaricide with stomach and
contact action. The compound is used to control a variety
of insects and mites in many crops such as nuts, artichokes,
olives, cotton, fruits, vegetables, tobacco, alfalfa, and sunflowers, and also in greenhouses and on rose cultures. It is
especially useful against scale insects.
Handelsname
CIBA-GEIGY® GS 13005®;
COBRACIDE®; FISONS NC® 2964; GEIGY® 13005; GS-13005®; SOMONIC®; SOMONIL®; SURPRACIDE®;
SUPRATHION®; ULTRACID®; ULTRACIDE®
Kontakt-Allergie
Methidation is an organophosphorus compound used as an insecticide. Cross-sensitivity was described to Dichlorvos.
Sicherheitsprofil
Poison by ingestion and
skin contact. Moderately toxic by inhalation.
Human mutation data reported. Human
systemic effects: coma, lachrymation, miosis.
A severe eye irritant. An insecticide. When
heated to decomposition it emits very toxic
fumes of NOx, POx, and SOx
Carcinogenicity
In a chronic toxicity/carcinogenicity study, rats were fed
diets with 0, 4, 40, or 100 ppm methidathion (equivalent to 0,
0.16, 1.72, or 4.91 mg/kg/day (males) and 0, 0.22, 2.20, or
6.93 mg/kg/day (females)) for 2 years, and there was no
evidence of carcinogenicity in either males or females .
Body weight decreases occurred in both sexes at the highest
dose throughout the study.
Environmental Fate
Photolytic. When methidathion in an aqueous buffer solution (25°C and pH 7.0) was
exposed to filtered UV light (l >290 nm) for 24 hours, 17% decomposed to 5-methoxy-
3H-1,3,4-thiadiazol-2-one. At 50°C, 56% was degraded after 24 hours. Degradation
occurred via hydrolysis of the thiol bond of the phosphorodithioic ester. Under acidic and
alkaline conditions, hydrolytic cleavage occurred at the C-S and P-S bonds, respectively
(Burkhard and Guth, 1979). Smith et al. (1978) demonstrated that methidathion degraded
to methidathion oxon at a faster rate in six air-dried soils than in moist soils. Half-lives
for methidathion in the air-dried soils ranged from 19 to 110 days. In addition, methidathion
degraded faster in an air-dried soil exposed to ozone (half-lives 2.5 to 7.0 days).
Chemical/Physical. Emits toxic fumes of phosphorus, nitrogen and sulfur oxides when
heated to decomposition (Sax and Lewis, 1987). Methidathion oxon was also found in
fogwater collected near Parlier, CA (Glotfelty et al., 1990). It was suggested
Stoffwechselwegen
The main route of methidathion metabolism in animals and plants is via
hydrolysis or oxidation (or hydrolysis of the oxon) to yield the 3-
thiomethyl-5-methoxy-1,3,4-thiadiazoldee rivative. This may either lose
methanethiol to yield the methoxy-1,3,4thiadiazolinone or be conjugated
as the cysteine derivative via a route involving desmethylmethidathion
(in plants). In plants and mammals an additional route involves the
methylation of the thiomethyl methoxy-1,3,4-thiadiazolinone derivative
by S-adenosylmethionine followed by oxidation to the corresponding
sulfoxide and sulfone which are excreted in the urine in mammals.
Another route of detoxification in insects, plants and mammals is via
demethylation of the 5-methoxy group of the 1,3,4-thiadiazolinone ring
to form a metabolite which may be conjugated in plants. As is common
with many phosphorothioates, the active acetylcholinesterase inhibitor,
methidaoxon, is usually detected in metabolism studies but at very low
concentration due to its rapid rate of hydrolysis.
Stoffwechsel
The principal degradation route is similar
both in animals and plants, that is, cleavage of the P?S
bond via oxidative desulfuration (activation) to the oxon
followed by hydrolysis to O,O-dimethyl hydrogen phosphorothioate
and the 3-thiomethyl-5-methoxythiadiazole
derivative, which is further degraded or conjugated.
Methidathion is rapidly degraded in soil; DT
50 in soil
is 3–18 d.
Versand/Shipping
Color code—Blue: Health Hazard/Poison: Store in
a secure poison location. Prior to working with this chemical, personnel should be trained on its proper handling and
storage. Store in tightly closed containers in a cool, wellventilated area
Waste disposal
Treat with strong alkali, mix
with soil and bury in the case of small quantities.
For large quantities, use incineration with effluent gas
scrubbing
Vorsichtsmaßnahmen
Occupational workers should be very careful during use and chemical management of methidathion. As this chemical substance is a highly toxic pesticide, it has been grouped by the US EPA as toxicity class I. The containers and labels of the products should bear the signal word DANGER. Methidathion is an RUP, except for use in nurseries, and on saffl ower and sunfl owers.
Methidathion (ISO) Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
