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Chemical Datasheet

PHOSPHORIC ACID, DIMETHYL 4-(METHYLTHIO) PHENYL ESTER

6.1 - Poison

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 3254-63-5
  • 3018
  • Poison
none
NIOSH Pocket Guide International Chem Safety Card
none none
NFPA 704
data unavailable
General Description
Colorless liquid. Used as a contact and systemic insecticide and acaricide. (EPA, 1998)

Hazards

Reactivity Alerts
none
Air & Water Reactions
Hydrolyzed by alkalis at 99.5 F. [EPA, 1998].
Fire Hazard
When heated to decomposition, it emits very toxic fumes of sulfur oxides and phosphorus oxides. (Non-Specific -- Organophosphorus Pesticide, Liquid, n.o.s.) Fire and runoff from fire control water may produce irritating or poisonous gases. Hydrolyzed by alkalies at 99.5F. (EPA, 1998)
Health Hazard
Highly toxic by oral or skin exposure. Its effects are probably due to action on the nervous system. This compound may cause death through respiratory arrest. (EPA, 1998)
Reactivity Profile
Organophosphates 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.
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
Excerpt from 152 Polymerizable warning [Substances - Toxic (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)
Firefighting
(Non-Specific -- Organophosphorus Pesticide, Liquid, n.o.s.) Wear positive pressure breathing apparatus and special protective clothing. Dike fire control water for later disposal; do not scatter the material.

(Non-Specific -- Organophosphorus Pesticide, Liquid, n.o.s.) Small fires: dry chemical, carbon dioxide, water spray, or foam. Large fires: water spray, fog, or foam. Move container from fire area if you can do it without risk. Fight fire from maximum distance. (EPA, 1998)
Non-Fire Response
(Non-Specific -- Organophosphorus Pesticides) Keep material out of water courses and sewer. Build dikes to contain flow as necessary. Use water spray to knock down vapor. Do not touch spilled material. (Non-Specific -- Organophosphorus Pesticide, Liquid, n.o.s.) Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Remove and isolate contaminated clothing at the site. Do not touch spilled material; stop leak if you can do so without risk. Use water spray to reduce vapors.

Small spills: absorb with sand or other noncombustible absorbent material and place into containers for later disposal.

Large spills: dike far ahead of spill for later disposal. (EPA, 1998)
Protective Clothing
For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
Warning: Effects may be delayed up to 12 hours. Caution is advised.

Note: Phosphoric acid, dimethyl 4-(methylthio)phenyl ester is a cholinesterase inhibitor.

Signs and Symptoms of Phosphoric Acid, Dimethyl 4-(Methylthio) Phenyl Ester Exposure: Acute exposure to phosphoric acid, dimethyl 4-(methylthio)phenyl ester may produce the following signs and symptoms: sweating, pinpoint pupils, blurred vision, headache, dizziness, profound weakness, muscle spasms, seizures, and coma. Mental confusion and psychosis may occur. Excessive salivation, nausea, vomiting, anorexia, diarrhea, and abdominal pain may occur. The heart rate may decrease following oral exposure or increase following dermal exposure. Chest pain may be noted. Hypotension (low blood pressure) may be observed, although hypertension (high blood pressure) is not uncommon. Respiratory signs include dyspnea (shortness of breath), pulmonary edema, respiratory depression, and respiratory paralysis.

Emergency Life-Support Procedures: Acute exposure to phosphoric acid, dimethyl 4-(methylthio)phenyl ester may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:
1. Move victims to fresh air. Emergency personnel should avoid self-exposure to phosphoric acid, dimethyl 4-(methylthio)- phenyl ester.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Transport to a health care facility.

Dermal/Eye Exposure:
1. Remove victims from exposure. Emergency personnel should avoid self-exposure to phosphoric acid, dimethyl 4- (methylthio)phenyl ester.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Remove and isolate contaminated clothing as soon as possible.
4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.
5. Wash exposed skin areas thoroughly with water.
6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
7. Transport to a health care facility.

Ingestion Exposure:
1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
3. Vomiting may be induced with syrup of Ipecac. If elapsed time since ingestion of phosphoric acid, dimethyl 4-(methylthio)- phenyl ester exposure is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step
4. Ipecac should not be administered to children under 6 months of age. Warning: Ingestion of phosphoric acid, dimethyl 4 (methylthio)phenyl ester may result in sudden onset of seizures or loss of consciousness. Syrup of Ipecac should be administered only if victims are alert, have an active gag reflex, and show no signs of impending seizure or coma. If ANY uncertainty exists, proceed to Step
4. The following dosages of Ipecac are recommended: children up to 1 year old, 10 mL (1/3 oz); children 1 to 12 years old, 15 mL (1/2 oz); adults, 30 mL (1 oz). Ambulate (walk) the victims and give large quantities of water. If vomiting has not occurred after 15 minutes, Ipecac may be readministered. Continue to ambulate and give water to the victims. If vomiting has not occurred within 15 minutes after second administration of Ipecac, administer activated charcoal.
4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water.
5. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults.
6. Transport to a health care facility. (EPA, 1998)

Physical Properties

Chemical Formula:
  • C9H13O4PS
Flash Point: data unavailable
Lower Explosive Limit (LEL): May burn but does not ignite readily. (EPA, 1998)
Upper Explosive Limit (UEL): May burn but does not ignite readily. (EPA, 1998)
Autoignition Temperature: data unavailable
Melting Point: data unavailable
Vapor Pressure: data unavailable
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 1.273 at 70.52°F (EPA, 1998) - Denser than water; will sink
Boiling Point: data unavailable
Molecular Weight: 248.25 (EPA, 1998)
Water Solubility: data unavailable
Ionization Energy/Potential: data unavailable
IDLH: data unavailable

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Phosphoric acid, dimethyl-p-(methylthio)phenyl ester (3254-63-5) 0.64 mg/m3 7 mg/m3 42 mg/m3
(DOE, 2018)

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Phosphoric acid, dimethyl 4-(methylthio) phenyl ester 3254-63-5 500 pounds 500 pounds

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names