© 2026 Nanjing Finechem Holdings Co., Ltd,
All Right Reserved
Chemical Name: Fenpropathrin
Chemical Class: Synthetic pyrethroid insecticide
Common Uses: Farmers use Fenpropathrin to fight off mites and insects attacking fruit, vegetable, and row crops. Pest control folks sometimes rely on it for outdoor ant, tick, and spider problems.
Appearance: Clear to yellowish-brown liquid
Odor: Mild chemical smell
CAS Number: 39515-41-8
Hazard Classes: Acute toxicity (oral, dermal, inhalation), skin and eye irritation, neurotoxicity
Signal Word: Warning
Symptoms of Exposure: Skin contact may lead to tingling, redness or rash. Inhaling the vapor or getting it in your eyes can trigger headaches, dizziness or sometimes blurred vision and eye watering. Large amounts, especially by swallowing or significant skin exposure, affect the nervous system. Shivers or muscle twitching are possible.
Chronic Effects: Workers breathing it in day after day may report mild numbness, shaky hands, or even trouble walking straight. Some animal studies have pointed to liver changes with long exposure, though people rarely experience these levels in the field.
Environmental Effects: Strongly toxic to aquatic life, so any runoff into streams or lakes threatens fish and water insects.
Main Ingredient: Fenpropathrin (chemical structure consists of 2,2,3,3-tetramethylcyclopropanecarboxylic acid ester)
Concentration: Generally available between 10% to 30% active ingredient in agricultural formulations
Inert Ingredients: Solvents, surfactants, and carriers, often proprietary but usually petroleum-based liquids and emulsifiers. Real impact comes from the main insecticide, since most other ingredients make it easier to spray and spread on crops.
Inhalation: Move to fresh air quickly. Stop any activity with further exposure. If the person feels dizzy, allow them to sit and catch their breath. Medical help is needed if symptoms stick around.
Skin Contact: Remove contaminated clothing and wash skin with soap and water, paying special attention to under nails and jewelry. Keep exposed skin uncovered and dry afterwards.
Eye Contact: Rinse eyes with clean water or saline for at least 15 minutes, lifting eyelids occasionally. Get checked by a doctor if burning won’t fade.
Ingestion: Avoid trying to make the person vomit unless a medical provider specifically tells you. Rinse mouth with water. Head to a clinic or poison center right away if someone swallowed any of this chemical.
Possible Complications: Some folks might feel tingling or numbness of lips, fingers, or face that can last for hours. If so, keep hands washed and avoid touching sensitive skin.
Suitable Extinguishing Media: Dry chemical, carbon dioxide, foam. Water spray for larger fires.
Specific Hazards: Burning Fenpropathrin releases toxic fumes including hydrogen chloride, carbon monoxide, and possibly some nitrogen oxides. Fire fighters face smoke that’s rough on lungs.
Protective Equipment: Firefighters need self-contained breathing gear and full protective suit, since the chemical vapor can harm mucous membranes easily.
Special Considerations: Avoid runoff from firefighting entering drains or bodies of water. If the chemical tanks or drums are exposed to fire, cool them from a distance with water, but avoid direct spray on the chemical itself.
Personal Precautions: Workers handling a spill wear gloves, long sleeves, chemical-resistant boots, and goggles. If the leak is big enough to smell or sting eyes, use a respirator.
Environmental Precautions: Keep spills off the ground, especially near drains and waterways. Surround with sand, earth, or absorbent pads.
Cleanup Method: For small leaks, absorb liquid with inert material like sand or diatomaceous earth and put it into labeled, lockable containers for later disposal. Wash off remaining residue with as little water as possible and collect runoff for safe disposal.
Further Steps: Ventilate the affected area thoroughly before resuming work.
Handling Practices: Only trained folks should open or mix this chemical. Don’t eat, smoke, or drink where you handle Fenpropathrin, and wash your hands and forearms right after. Pour slowly to keep splashing low.
Storage Conditions: Store Fenpropathrin in tightly sealed containers made of compatible material, well away from sunlight or sources of intense heat. Avoid areas where children or animals might get access. Keep it separate from food and animal feed. Make sure the space stays dry and ventilated.
Control of Static: Ground all containers and equipment before pumping to avoid sparks.
Occupational Exposure Limits: No specific regulatory workplace limit in many countries, but people working with the chemical typically use values set for other pyrethroids as a guideline.
Engineering Controls: Prepare solutions in well-ventilated areas. Where vapors collect, use fans or exhaust hoods directed outside.
Personal Protection: Long-sleeved shirt, long pants, chemical-resistant gloves, and safety goggles or a face shield. Change out of work clothes before going home. For mixing or spraying, some applicators wear a respirator for extra control.
Hygiene Recommendations: Wash up right after finishing work. Store personal gear separately from regular clothes, and don’t wear contaminated clothes again before they’ve been thoroughly cleaned.
Appearance: Clear to yellowish-brown oily liquid
Odor: Light, chemical scent
Boiling Point: Typically above 200°C
Melting Point: Below room temperature, stays liquid in normal conditions
Solubility: Practically insoluble in water, but readily forms emulsions when mixed with surfactants
Vapor Pressure: Low, less evaporative than many other common pesticides
Stability in Solution: Stays pretty steady in standard conditions for years if unopened, but breaks down faster in bright sunlight and hot weather.
Density: Often higher than water, sinks in a spill if mixed outside tanks.
Chemical Stability: Fenpropathrin keeps well in cool, dry places. Unstable if mixed with strong acids, bases, or strong oxidizers.
Conditions to Avoid: Bright sunlight, heat, open flame. These cause breakdown, with more vapors.
Hazardous Reactions: Not known to polymerize or violently react in storage, but toxic gases form if exposed to fire or incompatible chemicals.
Decomposition Products: Hydrogen chloride, carbon monoxide, carbon dioxide, and possibly other small organics given enough heat.
Acute Toxicity: Swallowing moderate amounts causes stomach pain, nausea, vomiting, and sometimes muscle jerkiness or tremors. Symptoms move quickly to the nervous system, particularly in children.
Dermal Effects: Even with gloves, repeated or heavy skin contact can bring numbness, tingling, and itching – now recognized as “pyrethroid syndrome.”
Inhalation Risks: High enough vapor levels, typically indoors, cause headache, nose-throat irritation, or even brief dizziness and confusion.
Chronic Effects: Studies in rats and mice noticed liver damage and some reproductive impacts with very high exposure, but these don’t necessarily match typical use patterns for people.
Carcinogenic Status: Not listed as a proven human carcinogen by agencies like the IARC or EPA.
Aquatic Toxicity: This insecticide devastates small fish, frogs, and aquatic insects, even at very low levels. Once mixed with rainwater and running off fields, the chemical lingers in stream sediments for weeks.
Soil Behavior: In dirt, Fenpropathrin tends to cling to particles and doesn’t travel fast through soil layers. With sun and air exposure, nature slowly breaks it down, but shade and heavy soil keep it around for months.
Effects on Bees: Pollinator insects take a hit from this chemical. If sprayed during bloom, it cripples bee activity, which farmers already know hurts their crops in the long run.
Small Quantities: Make sure leftover solutions, rinsates, or container rinsings go into official chemical waste drums – not down the sink or in compost. Rural disposal rules often require burning in high-temp incinerators or sending sealed containers to a certified hazardous landfill.
Contaminated Packaging: Triple-rinse empty drums and send them to specialized recycling or waste centers. Thin plastic containers shouldn’t be reused for water or food.
National Laws: Every country sets its own rules – in most places, dumping or burning without control will mean big fines or worse. Work with a professional disposal company if in doubt.
Classification: Dangerous good for both road and sea transport
Packing Group: Depending on concentration, often treated as class 9 (miscellaneous hazardous substances)
Signage: Containers carry toxic and environmental hazard marks. Truck placards typically warn of hazardous chemicals aboard.
Handling on the Road: Drivers carry records describing the load, and proper spill kits come standard with any shipment. Spills during transit need to be reported and cleaned by properly equipped teams.
Air Transport: Many airlines have restrictions on shipping pesticides like Fenpropathrin. The carrier or freight forwarder confirms if the material gets on board.
Approval Status: Reviewed by environmental and pesticide authorities (such as EPA, EFSA, and regulators in Japan and China).
Permitted Uses: Rules change frequently. While still found on orchards and fields, mounting restrictions in the US, EU, and elsewhere narrow what crops and times Fenpropathrin can be used.
Worker Safety: Farmers, ranchers, and landscape crews receive leaflets and label instructions on minimizing exposure – including what gear to wear, how to mix, and where run-off is illegal.
Consumer Food Residue: Authorities set maximum residue limits well below what causes any effect. Still, calls for tighter limits show up with each new batch of health data.
