Pyrethrin I

  • 2,2-Dimethyl-3-(2-methyl-1-propenyl) cyclopropanecarboxylic acid
  • 2-Methyl-4-oxo-3-(2,4-pentadienyl)-2-cyclopenten-2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropane carboxylate
  • (+)-Pyrethronyl (+)-trans-Chrysanthematee
Formula
C21H28O3
Structure
Description
Viscous liquid.
Uses
Insecticide.

Registry Numbers and Inventories.
CAS
121-21-1
EC (EINECS/ELINCS)
204-455-8
EC Index Number
613-023-00-1
EC Class
Harmful; Dangerous for the Environment
RTECS
GZ1725000
RTECS class
Agricultural Chemical and Pesticide; Natural Product
Beilstein/Gmelin
2004306
Beilstein Reference
3-09-00-00215
EPA OPP
69008
Swiss Giftliste 1
G-2045
Canada DSL/NDSL
DSL
Austrailia AICS
Listed
New Zealand
Listed

Properties.
Formula
C21H28O3
Formula mass
328.49
Boiling point, °C
146 - 148 (0.002 torr)
Vapor pressure, mmHg
2E-5 (25 C)
Density
1.5192 g/cm3 (18 C)
Solubility in water
0.2 mg/L
Refractive index
1.5237 (20 C)
Partition coefficient, pKow
5.9

Hazards and Protection.
Storage
Keep containers tightly closed in a well ventilated area. Should be refrigerated and stored in darkness.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate eye protection and protective clothing to prevent skin and eye contact.
Respirators
Condition: emergency or planned entry into unknown concentrations or idlh conditions. Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive pressure-mode. Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive-pressure mode.
Small spills/leaks
Evacuate area and ventilate. Wear protective equipment. If required, use an inert absrobent. Sweep up and place in an appropriate container for disposal. Wash contaminated surfaces.
Stability
Oxidizes readily and becomes inactive in air. Pyrethrins are decomposed by exposure to light with loss of insecticidal activity. They are rapidly oxidized and inactivated by air. As the pyrethrins approach 100% purity, their stability decreases; pyrethrin i and ii are less stable than the other compounds. Pyrethrins synergists have a stabilizing effect.
Incompatibilities
Incompatible with alkalies. Avoid contact with strong oxidizers. Incompatible with lime and ordinary soaps because acids and alkalies speed up processes of hydrolysis.

Fire.
Fire fighting
Use appropriate media to suppress exposure fire. Use foam, carbon dioxide, dry chemicals when oil formulation is burning, due to hydrocarbon solvents involved.
Fire potential
Slightly flammable. Flammable liquid.

Health.
Exposure limit(s)
IDHL: 5000 mg/m3.
Poison_Class
3
Exposure effects
   Ingestion
Nausea, vomiting and abdominal pain commonly occur and develop within 10 to 60 minutes following ingestion.
   Inhalation
Hypersensitivity reactions characterized by pneumonitis, cough, dyspnea, wheezing, chest pain, and bronchospasm may occur. Rare cases of respiratory failure and cardiopulmonary arrest have been reported.
   Skin
Irritant and contact dermatitis may develop. Erythema which mimics sunburn has also been noted after prolonged repeated exposure.

First aid
 
   Ingestion
There is no specific antidote for pyrethrin poisoning. Treatment is symptomatic and supportive and includes monitoring for the development of hypersensitivity reactions with respiratory distress. Provide adequate airway management when needed. Gastric decontamination is usually not required unless the pyrethrin product is combined with a hydrocarbon. Allergic reaction: mild: antihistamines with or without epinephrine. Severe: oxygen, aggressive airway management, antihistamines, epinephrine (adult: 0.3 To 0.5 Ml of a 1:1000 solution subcutaneously; child: 0.01 Ml/kg; may repeat in 20 to 30 min), corticosteroids, ecg monitoring, and iv fluids.
   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. Vitamin e topical application is highly effective in relieving paresthesias.
   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.