Regulations - Organochlorines Flashcards
What is the governing agency that regulates pesticides?
EPA - environmental protection agency
What are the two major federal pesticide statuses regulated by the EPA?
FIFRA (federael insecticide, fungicide, and rodenticide act) - governs the sale and use of pesticide products in the US.
FFDCA (federal food, drug, and cosmetic act) - governs the limit of pesticide residues on food and feeds
What does the EPA determine?
Whether a “safe” level of pesticide residue, called a “tolerance” can be established before registration
The EPA specifies approved uses and conditions of uses, including what?
safe methods of handling (personal protection, ventilation, etc), storage, and disposal
must be explained on the product label - material safety data sheet
What are some natural sources of organochlorines?
through biological, physical, and chemical processes
- include bacteria, fungi, plants, marine organisms, insects, and other animals, to forest fires, volcanoes, and other geothermal events
- major sources include oceans followed by soil
what are some synthetic sources of organochlorines?
- chlorination modifies the physical properties of hydrocarbons in several ways resulting in a wide structural variety and divergent chemical properties that leads to a broad range of names and applications.
what are some chemical properties of organochlorines?
- persistent in the environment –> chlorination of the organic compounds reduces reactivity - results in increased size, decreased volatility, increased boiling point - MORE STABLE
- persistent in the environment!
- lipophilic
what are the two main groups of organochlorine pesticides?
DDT type compounds
chlorinated alicyclics (open and closed chains)
What was the effect of DDT on many birds?
- biomagnification
- eggshell thinning - estrogen like activity impairs the shell gland’s ability to excrete calcium carbonate to harden the shell
endocrine disruptor
what was an unintentional consequence of DDT use?
- DDT was used to reduce malaria in Borneo
- observed that thatched roofs were collapsing because DDT killed the wasps that ate thatch eating caterpilars
- dead wasps were eaten by lizards and then eaten by cats
- cats died as a result –> increase in rodents
- increase in rodent related diseases
- stop use of DDT
- CAT DROP to drop an excess of 20 cats in the area
Why were organochlorines developed?
to replace DDT (methoxychlor)
what are the uses of Methoxychlor?
used to protect crops, ornamentals, livestock, and pets against fleas, mosquitoes, cockroaches, and other insects
what was the problem with organochlorines?
Methoxychlor
- acute toxicity
- bioaccumulation
- endocrine disruption
Lindane (lice and scabies)
- banned by the EPA for agricultural use but still used for pharmaceutical use in humans and animals
how are animals exposed to organochlorines?
- label directions not followed
- concentrations miscalculates for sprays or dips
- contaminated feed or water
- packages or containers unsecured or unlabeled
- lack of appropriate PPE
How are organochlorines absorbed?
- dermal most common - damaged skin facilitates absorption
- inhalation and oral as well
