toxicityindia

Chemical Pesticides Agro Chemicals

 

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 IIRT
IIRT plays an important role in analyzing and certifying the pesticides both technical grade and formulations for their safe use. IIRT 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 IIRT
IIRT 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 IIRT
IIRT 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 IIRT
IIRT 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 IIRT
IIRT 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
IIRT 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

  • IIRT provides the customer based requirements for development of different type of pesticides formulations whether aqueous based or oil based.
  • IIRT also provides the services for development of surface-active agents for the pesticide formulations. It includes the development of new generation environmental friendly formulations.
 

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