science

Phenothrin

Phenothrin is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Phenothrin rather than just read about it. In short: Phenothrin, also called sumithrin and d-phenothrin, is a synthetic pyrethroid that kills adult fleas and ticks. It has also been used to kill head lice in humans. d-Phenothrin is used as a component of aerosol insecticides for domestic use.

Key takeaways

Phenothrin belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Phenothrin to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Phenothrin from memory before moving on to harder problems.

Reference excerpt

Phenothrin, also called sumithrin and d-phenothrin, is a synthetic pyrethroid that kills adult fleas and ticks. It has also been used to kill head lice in humans. d-Phenothrin is used as a component of aerosol insecticides for domestic use. It is often used with methoprene, an insect growth regulator that interrupts the insect's biological lifecycle by killing the eggs.

Effects Phenothrin is primarily used to kill fleas and ticks. It is also used to kill head lice in humans, but studies conducted in Paris and the United Kingdom have shown widespread resistance to phenothrin. It is extremely toxic to bees. A U.S. Environmental Protection Agency (EPA) study found that 0.07 micrograms were enough to kill honey bees. It is also extremely toxic to aquatic life with a study showing concentrations of 0.03 ppb killing mysid shrimp. It has increased risk of liver cancer in rats and mice in long-term exposure, with doses in the range of 100 milligrams per kilogram of body weight per day, or above. It is capable of killing mosquitoes, although remains poisonous to cats and dogs, with seizures and deaths being reported due to poisoning. Specific data on concentrations or exposure are lacking. Phenothrin has been found to possess antiandrogen properties, and was responsible for a small epidemic of gynecomastia via isolated environmental exposure. The EPA has not assessed its effect on cancer in humans. However, one study performed by the Mount Sinai School of Medicine linked sumithrin with breast cancer; the link made by its effect on increasing the expression of a gene responsible for mammary tissue proliferation.

EPA action In 2005, the U.S. EPA cancelled permission to use phenothrin in several flea and tick products, at the request of the manufacturer, Hartz Mountain Industries. The products were linked to a range of adverse reactions, including hair loss, salivation, tremors, and numerous deaths in cats and kittens. In the short term, the agreement called for new warning labels on the products. As of March 31, 2006, the sale and distribution of Hartz's phenothrin-containing flea and tick products for cats has been terminated. However, EPA's product cancellation order did not apply to Hartz flea and tick products for dogs, and Hartz continues to produce many of its flea and tick products for dogs.

See also Permethrin Resmethrin Deltamethrin

References

External links d-Phenothrin general information – National Pesticide Information Center Pyrethrins and Pyrethroids Fact Sheet – National Pesticide Information Center Pyrethrins and Pyrethroids Pesticide Information Profile – Extension Toxicology Network Phenothrin in the Pesticide Properties DataBase (PPDB)

Illustrations

Worked examples

Example 1 — a first encounter with Phenothrin

Start with the simplest possible case. Write down what Phenothrin claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Phenothrin before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Phenothrin ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Phenothrin

In research: Phenothrin appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Phenothrin in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Phenothrin is common in secondary-school and first-year university syllabi. It links to neighbouring topics (3-phenoxyphenyl)methyl 2,2,3-trimethylcyclopropane-1-carboxylates, Chrysanthemate esters, Endocrine disruptors, so understanding it makes those chapters shorter.
In everyday life: Look for Phenothrin outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Phenothrin in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Phenothrin means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Phenothrin out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Phenothrin in simple terms?

Why does Phenothrin matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Phenothrin?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Phenothrin.