How do pyrethroids behave in sunlight?

How do pyrethroids behave in sunlight?

• A. They rapidly degrade when exposed to sunlight
• B. They volatilize into the air with sunlight
• C. They remain stable in sunlight
• D. They are unstable and quickly break down in sunlight

Answer: (D)

Sunlight makes pyrethroids photolyze. When these molecules absorb UV energy, their bonds break, converting the active ingredient into different, less active or inactive compounds. This causes a rapid loss of insecticidal activity, so pyrethroids are unstable and break down quickly in sunlight. They don’t rely on volatilizing into the air as the main fate under sun, and they don’t remain stable when exposed to sunlight.

Sunlight makes pyrethroids photolyze. When these molecules absorb UV energy, their bonds break, converting the active ingredient into different, less active or inactive compounds. This causes a rapid loss of insecticidal activity, so pyrethroids are unstable and break down quickly in sunlight. They don’t rely on volatilizing into the air as the main fate under sun, and they don’t remain stable when exposed to sunlight.