Chemicals, Pesticides And Agrochemicals
What are Pesticides ?
Pesticides are chemicals used to control pests. The term 'pesticide'
includes insecticides, herbicides, fungicides, algaecides and fumigants.
Thrust Areas.
- Analysis of technical grade pesticides and formulations
- Residual pesticide analysis
- Establishing of MRL values for pesticides
- Certification of organic farming products
- Shelf life studies as per CIB guidelines
- Analytical toxicology of agrochemicals
|
Analysis of Technical
Grade Pesticides and Formulations
What are Technical Grade Pesticides ?
Technical grade pesticides are chemical compounds consisting of 85 percent
or more of the active chemical constituent and the rest are impurities
produced during chemical synthesis.
What are Pesticide Formulations ?
Pesticide formulation consists of one or more active pesticide ingredients
plus other ingredients which have no pesticidal action i.e. inert
ingredients. Inert ingredients generally include, fillers, talc, petroleum
distillate, solvents, wetting agents, extenders, emulsifiers, adjuvants etc.
Types of Formulations
Depending upon the intended use of pesticides there are different types of
formulations
|
Solids
Dust or powders Granules, Pellets, Tablets Particulates or Baits
Dry flowables
Wettable powders
Ear tag/Vapour strips
Seed treatment WDGs
|
Liquids
Suspensions Concentrate (Flowables)
Solutions Emulsifiable concentrates
Gels Aerosol
Ultralow volume concentrates
Microemulsions Suspoemulsions |
Gases
Fumigants sold as liquids or solids |
Factors Responsible for different types of formulations
- Chemistry of the active ingredient
- Toxicology of active ingredient
- Effectivity of the product against the pest
- Effectivity of the product on the plant, animal or surface
- Effectivity of the product on the environment
- Method of application and equipment used
- Rate of application
|
Why is the analysis required for the technical grade
pesticides and the pesticide formulations
- To ensure the percentage purity of active ingredient in both
technical gradesand formulations as per the labelled claim by the
manufacturers
- To ensure the suitability of the pesticide formulation for its
intended use.
- To ensure safe and judicious use of pesticides
- To ensure the shelf life of active ingredient.
|
What are the quality norms and protocols followed for
analysis
1. Analysis is done as per both National and International standards with
following major protocols:
- Bureau of Indian Standard specifications.
- CIPAC
- WHO specifications
- FAO specifications
- AOAC specifications
|
2. In-house validated method and
procedure
3. Party's specification
Test Parameters
In order to ensure the right quality of the pesticide, besides testing for
the active ingredient, it is also necessary to test other parameters give in
the list below :
|
Type of Materials / Formulations
|
Test parameters
|
|
Technical grade pesticides |
Moisture content, melting point, setting point,
isomeric ratio, relative density, acidity / alkalinity |
|
Water dispersible powder |
Sieving test, suspensibility, wettability, acidity /
alkalinity |
|
Dusting powder |
Sieving test for particle size, bulk density after
compacting, acidity / alkalinity |
|
Granules |
Encapsulation i.e. Attrition test and water run-off
test, sieving test for granule size, sieving test for dust, moisture,
acidity/alkalinity. |
|
Emulsifiable concentrates, Soluble liquids |
Emulsion stability, cold test, acidity/alkalinity,
flash point. |
Role of SRI
SRI plays an important role in analyzing and certifying the pesticides both
technical grade and formulations for their safe use. SRI has the facilities
to carry all the above mentioned tests to ascertain the conformity various
national or international specifications.
Analysis of Residual Pesticides
|
Major Categories of Residual
Pesticides |
|
Organochlorines
- Solids
- Poor water solubility
- Highly lipophilic
- Persistent and toxic
- Accumute in animal fat accumulates |
Organophosphorus
- Liquids
- Appreciable water solubility
- Rapidly metabolized
- Not very persistent
- Highly toxic |
Pyrethroids
- Solids, used for health care
- Partially water soluble
- Rapidly degraded
- Not persistent
- Highly toxic |
|
Organochlorines and organophosphorus pesticides are of major concern as
they accumulate in animal body fat either as such or in the form of
metabolites.
What are the causes of Residual Pesticides ?
- Persistent nature of pesticides
- Unawareness amongst farmers
- Contamination of water and soil
- Direct application of pesticides during storage
- Improper timings of pesticide application
|
Why is it important to analyse
residual pesticides ?
It is important to analyze residual pesticides because
- Residual pesticides is one of the important factors to prove that
the food is safe for consumption
- Mandatory requirements by regulatory authorities for all exports
of food and food products
- Mandatory requirement of PFA for domestic market
|
Role of SRI
SRI has the state of the art equipment and technology for :
- Residual analysis of all pesticides in ppb to sub ppb levels as
per the EU, WHO, USFDA and PFA norms as applicable in
|
|
Food grains
Fruits and vegetables
Meat and meat products
Water and Beverages |
Honey
Milk and milk products
Spices
Processed foods |
- Method development and validation for determination of residual
pesticides in complex matrices
- Data generation for studying residual effects of new pesticide
molecules for registration of the product with CIB
|
Establishing Maximum Residual Limits
(MRL) values for pesticides
What is MRL value ?
MRL is the maximum concentration for a possible residue on crop or food
commodity resulting from the use of pesticides and is expressed in mg/kg of
the commodity.
What is the status of MRL values for various pesticides registered
in India ?
|
Number of pesticides registered in India
Pesticides for which MRLs have been fixed under PFA act, 1954
Pesticides for which MRLs yet to be fixed
Pesticides for which registration data has been submitted but MRLs not
fixed
Pesticides for which no data is available |
- 181
- 71
- 32
- 24
- 8 |
|
For certain banned pesticides - Still no data is
available |
Why is it necessary to generate data to establish the MRL values ?
- For India to build its own food standards based on scientific and
health criteria under the Indian conditions keeping in view the
international norms.
- Revision of standards to be an ongoing process
- R & D on daily intake of various food items to decide the
intake rate of pesticides
- Regular agreement of actual exposure of consumers to pesticide
residues with respect to the diet basket.
|
Role of SRI
SRI has all the sophisticated equipment and technology and can help to fix
the MRL values for various pesticides in different food and farm products.
Packaging/Shelf Life or Stability Enhancement of Shelf Life Studies
What is Shelf life
Shelf life refers to the period from initial preperation and packaging
during which the technical grade pesticides or the formulation remains
within its physical, chemical and toxicological specifications at the
specified storage condition. It should meet the appropriate standards of
identity, quality and purity of active ingredient.
What are the factors affecting Pesticide Stability
- Environmental factors such as:
- Temperature
- Light
- Air
- Oxygen
- Moisture
- Carbon dioxide
- Other ingredients in the formulations
- Leachings from containers
|
How are the stability tests
conducted ?
- Stability testing of pesticides is based upon well designed
studies to determine the retention of product integrity (i.e.
percent active ingredient, physical characteristics, chemical
parameters and efficacy) as a function of time. Studies are done at
accelerated conditions as well as controlled room temperature
conditions.
- The product samples are analysed at various intervals by
validated analytical methods.
|
Why is it important to conduct
shelf life / stability studies ?
It is a mandatory requirement by CIB that the manufacturers should submit
the data for shelf life studies at the time of getting their product
registered.
Role of SRI
SRI has the complete arrangement to take up the studies for shelf life or
enhancement of shelf life as per the CIB guidelines.
According to CIB guidelines :
- Pesticides or their formulations are stored under three different
agro-climatic conditions of the country
- Properties are determined at fixed intervals of time over a
prolonged period to study the deterioration pattern
|
Certification of Organic
Farming
What is organic farming ?
Organic farming refers to agricultural methods
- Without any use of chemical pesticides, fungicides or weedicides
- Without any use of chemical fertilizers (eg urea, potassium
sulfate, superphosphate etc.)
|
What are the principles involved
in organic farming ?
The principles involved in organic farming are :
- All seeds and plant material should be certified as organic i.e.
seeds and plants should not be chemically treated with any synthetic
pesticides.
- Accumulation of heavy metals in the soil should be minimal
- Manure should be certified as organic
- Water used for irrigation should be free from pesticides or heavy
metal contamination.
- The livestock should be fed 100% organically grown feed of good
quality
- All relevant measures should be taken to minimize pesticide
contamination from outside and within the farm by wind drift,
drainage and irrigation.
- No use of fumigants or chemicals during storage
|
What does organic certification
involve ?
Organic certification involves
- Farm certification
- Product certification
|
Role of SRI
SRI plays an important role in certification of organic farming by carrying
out analysis of samples of :
- Product of organic produce
- Crop during the stages of its growth
- Soil used for organic farming
- Feed for the live stock
- Water used for irrigation
|
For the following contaminants
- Pesticides, herbicides or fungicides
- Heavy metals
- Minerals and fertilizers
|
Analytical Toxicology of Agrochemicals
SRI provides comprehensive range of toxicity studies as per the national
and international norms for different pesticides and their formulations by
carrying out -
Acute / Sub acute toxicity studies by following routes :
- Oral
- Dermal
- Inhalation
- Skin and eye irritation
|
Studies are conducted on mice,
rabbits, guinea pigs, fish, bird, honey bee etc.
- Long term toxicity studies
- Mutagenecity studies
- Reproductive studies on rats
- Carcinogenecity studies on rats and mice
|
Development of pesticide
formulations
- SRI provides the customer based requirements for development of
different type of pesticides formulations whether aqueous based or
oil based.
- SRI also provides the services for development of surface-active
agents for the pesticide formulations. It includes the development
of new generation environmental friendly formulations.
|
© Shriram Institute for Industrial Research. All Rights
Reserved (Terms
of Use)