Methylphosphonic acid

  • Dihydrogen methylphosphonate
  • Methanephosphonic acid
  • MPA
Formula
CH5O3P
Structure
Description
White, crystalline flakes.
Uses
Organic synthesis.

Registry Numbers and Inventories.
CAS
993-13-5
EC (EINECS/ELINCS)
213-607-2
S 26 36/37/39 45
UN (DOT)
3261
Beilstein/Gmelin
1739372
Beilstein Reference
4-04-00-03498
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
CH5O3P
Formula mass
96.02
Melting point, °C
107.5
Density
1.639 g/cm3 (20 C)
Solubility in water
> 20 g/L
pKa/pKb
2.12 (pKa)
Partition coefficient, pKow
-0.09

Hazards and Protection.
Storage
Keep in a cool, dry location in a tightly closed container.
Handling
Avoid prolonged or repeated exposure. Don’t breathe dust. Prevent exposure by using protective equipment.
Protection
Chemical splash goggles in compliance with OSHA regulations are advised; however, OSHA regulations also permit other type safety glasses. Whre chemical resistant gloves. To prevent repeated or prolonged skin contact, wear impervious clothing and boots.
Respirators
Respiratory protection (supplied-air respirator with full facepiece or self-contained breathing apparatus) should be available where these compounds are manufactured or used and should be worn in case of emergency and overexposure.
Small spills/leaks
Evacuate the area. Wear SCBA, rubber boots and gloves. Cover with dry lime or soda ash. Pickup and keep in a closed contaner for waste disposal. Wash area until material pickup is complete.
Stability
Stable at normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents.
Decomposition
Oxides of carbon and phosphorous, phosphine.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use agent most appropriate to extinguish fire.

Health.
Exposure effects
   Ingestion
Harmful if ingested.
   Inhalation
Inflammation and edema of the larynix and bronci. Chemical pneumontis, pulmonary edema and ubrns.
   Skin
Extremely corrosive to the skin. Causes chemical burns. Absorbed throught the skin.
   Eyes
Corrosive. Corneal damage.

First aid
 
   Ingestion
Seek medical attention. If individual is drowsy or unconscious, do not give anything by mouth; place individual on the left side with the head down. Contact a physician, medical facility, or poison control center for advice about whether to induce vomiting. If possible, do not leave individual unattended.
   Inhalation
Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with beta2 agonist and corticosteroid aerosols.
   Skin
Remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician should examine the area if irritation or pain persists.
   Eyes
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.

Transport.
UN number
3261
Response guide