Agent Name


CAS Number




Major Category



Octamethyl pyrophosphoramide; Bis(bisdimethylaminophosphonous) anhydride; Bis(bisdimethylaminophosphonous)anhydride; Bis(dimethylamino)phosphonous anhydride; Bis(dimethylamino)phosphoric anhydride; Bis-N,N,N',N'-tetramethylphosphorodiamidic anhydride; Diphosphoramide, octamethyl-; ENT 17,291; Lethalaire G-59; OMPA; Octamethyl; Octamethyl pyrophosphortetramide; Octamethyl tetramido pyrophosphate; Octamethyl-difosforzuur-tetramide [Dutch]; Octamethyl-diphosphorsaeure-tetramid [German]; Octamethyldiphosphoramide; Octamethylpyrophosphoramide; Octamethylpyrophosphoric acid amide; Octamethylpyrophosphoric acid tetramide; Octamidophos; Oktamethyl [Czech]; Oktamidofos [Czech]; Ompacide; Ompatox; Ompax; Ottometil-pirofosforammide [Italian]; Pestox; Pestox 3; Pestox 66; Pestox III; Pyrophosphoramide, octamethyl-; Pyrophosphoric acid octamethyltetraamide; Pyrophosphoryltetrakisdimethylamide; Schradan [ISO]; Schradane [French]; Systam; Systophos; Sytam; Tetrakisdimethylaminophosphonous anhydride; [ChemIDplus] UN3018


Organophosphate Insecticides


Liquid; mp = 14-20 deg C; [Merck Index] Dark brown liquid; mp = 14-20 deg C; [CAMEO]


Used as acaricide, systemic insecticide, and soil drench for transplanted trees; Absorbed by plants for long term insect and arachnid protection; No known current use; [HSDB]


Decrease in growth and whole blood cholinesterase activity were observed in one year feeding study with rats; No adverse histopathology or effects to brain activity were observed; Inhibits brain cholinesterase in animals far less than that in the blood; [HSDB] Highly toxic cholinesterase inhibitor; [CAMEO] The average of two baseline respective cholinesterase activity determinations three days apart, with no exposures to enzyme inhibiting pesticides for at least 30 days, is recommended for each worker prior to exposure to cholinesterase inhibitors because of large inter-individual differences in published baseline values. To be established at least once a year. Removal from workplace exposures is recommended until the cholinesterase activity returns to within 20% of baseline. [TLVs and BEIs]


Not registered with the EPA for use as pesticide in the US; [CAMEO]

Exposure Assessment

Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

Vapor Pressure

0.001 mm Hg

Lethal Concentration

LCLo (rat) = 8 mg/m3/4h

Explanatory Notes

The Guide in the Emergency Response Guidebook is for "Organophosphorus pesticide, liquid, toxic."

Adverse Effects
Other Poison


Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

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Related Information in HazMap

Occupational diseases associated with exposure to this agent:


Industrial Processes with risk of exposure: