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Food chemical safety

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Title: Food chemical safety

1
Food chemical safety
2
Chemical contaminants in foods

Characteristics
They are not added intentionally added to food.
Contamination can happen at one or more stages in
food production.
Illness is likely to result if consumers ingest
enough of them.
The above differentiate from other chemicals in
food such as vitamins and additives.

3
Examples of chemical contaminants

Pesticides
Herbicides
Fungicides
Veterinary drugs

4
Pesticides

eat your fruits and vegetables is one of the
recommendations for a healthy diet.
Use of pesticides and chemicals to protect fruits
and vegetables against insects and pests, and
moulds.
Correct and responsible use of pesticides can
enhanced yield and safety of these produce.

5
Use of pesticide

Must follow the limits sets by the Ministry for
use on food commodity, and the safe amount of
pesticide residue that may be present at the
point of sale.
The safe residue level conform with the
international standards set by Codex Alimentarius
Commision.

6
Potential hazard?

Pesticide residue.
Contamination of surface and ground water.
Persistent pesticide not degradable are removed
from the registration list.

7
Acceptable Daily Intake (ADI)

ADI is a measure of toxicity.
Calculated from a known toxicological effect of a
chemical (e.g. pesticide), example increased
serum glutamate pyruvate aminotransferase (SGPT)
in dicator of liver damage.
The dose of the pesticide below the point at
which the defined toxicological effect occurs in
animal studies is determeined (NO Observable
Adverse Effect Level NOAEL).
This is the maximum dose that can be consumed
without any adverse effect resulting.
ADI exceeds the level is rare, but cases of
lindane in milk (UK in1996) and chlormequat in
pears in 1999.

8
Maximum Residue Level (MRL)

MRL is not a toxicological parameters but a
trading standard set by national and
international authorities (e.g. Codex
Alimentarius) to ensure that residues are
controlled in world food trade.
MRL is the pesticide residue level in particular
food following its production according to Good
Agricultural Practices (GAP) i.e. apply pesticide
at the right time and according to label
directions, appropriate withdrawal period (time
necessary between application of pesticide and
harvest) the crop is harvested and residue
determined.
If the level of pesticide exceed the MRL, the
crop has not been grown according to GAP and the
product not permitted to be sold, imported or
exported.

Exceeded the MRL has no health implication, but
the farmer has breached the national or
international regulations and is liable for
prosecution.
Exceeding the MRL is more common.

Pesticides must be in harmony with non target
pests and environment.
Those broad-spectrum pesticides and have long
residual effect were either removed from the
market or restricted usage.
The regulatory body is Pesticide Board of
Malaysia under the preview of the Ministry.

11
Pesticides withdrawn or partially banned by the
Pesticide Board of Malaysia

Aldrin withdrawn by the parent company
Diledrin ------do-----
Benomyl -------do-----
Chlordane total ban
DDT total ban
Heptochlor total ban
Penthachlorophenate partial ban not allowed for
paddy
Endosulphan partial ban not allowed for cocoa
and pepper
Lindane (gamma-BHC) partial ban allowed for
palm oil and coconut only
(total 17 pesticides)

12
Pesticides not allowed for use on vegetables

Some organophosphate pesticides, e.g.
methamidophos and monocrotophos, were registered
for use in vegetables but after review by the
Pesticide Board, they have been banned based on
their residue or toxicology problems.
All pesticides use in Malaysia must be
registered.
Comply the Pesticide Act 1974 and Food Act 1985,
for the registration, production, management and
application of pesticides.

13
DDT organochlorine(1,1-(2,2,2-trichloroethylid
ene)bis(4-chlorobenzene)

Dr. Paul Muller, a Swiss chemist won an Nobel
Prize in Medicine in 1948 for DDT, replacing
extremely dangerous chemicals for pest control
(arsenic, lead and mercury).
Effective against mosquitoes causing malaria,
kill lice, improve health in Sri Lanka.
1964 use of DDT was discontinued in Sri Lanka,
and coincide with publication of Carsons Silent
Spring.
Attack on DDT
cause thin egg shells. (ii) DDT is so stable and
could never be eliminated from the environment.
Safe for human? Cancer? (lipid solubles)
Repeated administration of DDT to animals results
in tremor, incoordination, muscular twitching and
weakness.
DDT is excreted in urine.

14
Organophosphate (OPs)

Oldest synthetic pesticides.
Common names organic phosphates, phosphate
insecticides, phosphorus esters or phosphoric
acid esters.
Genarally speaking they are most toxic to
vertebrate animals.
Mode of action is similar to nerve gas (potent
cholinesterase).
Attack nerve, death as a result of respiratory
failure.
e.g. malathion, parathion.
easily metabolized by esterase,low mammalian
toxicity.
Residues in food products do not normally result
in exposure sufficient to lead to health problems
in humans.
Pyrethroids green pesticide from chrysanthemum
(pyrethrum).

15
Other insecticides

Carbamates similar to Ops, water solubles,
contaminated water.
mode of action similar to Ops cholinesterase
inhibitors.
Cyclodiene e.g. aldrin and dieldrin, stable in
soil and relative stable to uv of sunlight. Use
to control soil insects. Mode of action is
neurotoxicity.

16
Herbicides

Weed killers.
Trace residues present in final food products.
Chlorophenoxy acid esters 2,4-D and 2,4,5-T
No apparent adverse effects on human and animals.
The 2,4,5-T used in Agent Orange contains
excessive amounts of tetrachrodioxin, suspected
toxic impurity.
Bipyridyliums paraquat and diquat.
On contact plant tissues are quickly damaged.
Cases of accidental or suicidal fatalities from
paraquat poisoning.

17
Fungicides

Chemicals used to kill or stop the development of
fungi.
To treat plants, roots,seeds

18
Industrial and environmental contaminants

Most do not pose threats to human, but some
certain incidences have indicated that they can
be a potential hazard.

Halogenated hydrocarbons polychlorinated
Biphenyls (PCBs) or trade name Aroclor first
synthesise in1881.
Uses insulating fluids in electrical industries,
food packaging made from recycled paper, paints,
lubricants, insulating tapes, fireproofing
materials, and ink.
Considerable resistant to acids, bases, high
temperature, electrical current and is
nonflammable.
Safety no significant health threats to human.

20
Dioxin

TCDD (tetrachlorodibenzo-p-dioxin) are among most
potent toxicants known, chemically very stable
and binds strongly to to solids or particulate
matter in soil, is lipophilic but sparingly
soluble in water or organic liquids.
LD50 for TCDD in guinea pig is under 1 mg/kg
hamster is more than 10g/kg.
Toxicity affect the kidney and skin, promoter of
carcinogenesis and is a carcinogen. Liver
tumors, tumors of the mouth, nose and lung have
been found.
Three times more potent than aflatoxin B1.
In rhesus monkeys, TCDD is fetotoxic, resulting
in higher levels of abortion and death in
pregnant females.
Human exposure no fatalities, toxic effects
include fatigue, affect peripheral nervous system
and liver toxicity.

21
Heavy metals

Mercury exists in many forms.
metallic mercury, inorganic mercury compounds or
salts, organic mercury compounds.
Nervous system is very sensitive to all forms of
mercury. Exposure to high levels of metallic,
inorganic or organic mercury can permanently
damage the brain, kidneys and developing fetus.
Mercury chloride and methyl mercury are possible
human carcinogens.
Children are more sensitive to
Children are more sensitive to mercury than are
adults, can be passed through breast milk.

22
Mercury level in water

FDA maximum permissible level of 1ppm methyl
mercury in seafoods.
EPA mercury in drinking water 2 ppm.

23
Lead

Previously, this heavy metal was found in a
variety of consumer products (lead-based paints,
antiknock petrol, lead-glazed glasses, lead water
pipes, lead glazes, lead solders).
Lead poisoning is normally due to occupational
situations.
Children are most affected, lead absorption in
children is about 40, adult 10, highest in the
bone.
Anemia, neurological disorders in developing
children brains, can pass from placenta to fetus.
Elimination or minimize exposures.

24
Cadmium

Cadmium in food is as inorganic cadmiun salts.
Organic cadmium is unstable.
In Japan, chronic cadmium intoxication over 12-yr
period occurred in some population that consumed
rice contaminated with cadmium because of
pollution. Painful disease called itai itai
meaning ouch ouch bone disease, with symptoms
of skeletal deformation and multiple fractures.
Cadmium stays in the liver and kidneys.
Breathing air with very high levels of cadmium
can severely damage the lungs and cause death.

25
Arsenic

Found as inorganic and organic compounds. In
foods, drinking water, wine and other sources.
Used widely in manufacture of glass to remove
green colour cause by impurities.
Previously arsenic is used to treat syphilis
until penicillin and other sulfa drugs were
developed.
Arsenic is abundant in seafoods, but in an
organic form, not toxic, rapidly absorbed and
excreted in the urine and bile.
Classical syndromes of chronic arsenic exposure
include hyperkeratosis, corns and warts on the
feet and hands.
May be indirect carcinogen.
10 to 50 ppb may be necessary to maintain
homeostasis of the body, used successfully to
treat acute promyelocytic leukemia (APL).
Standard in drinking water is 10ppb.

26
Contaminants of Industrial and Environmental
Origin
CHEMICAL Polychlorinated biphenyls Dioxin Mercury Lead Cadmium Radionuclides SOURCE Electrical appliances Impurity Chlor-alkali Vehicle emission, smelting, paint, glazes, solder Sludge, smelting Accidental release ASSOCIATED FOOD Fish, animal fat Fish, milk, beef fat Fish Vegetables, canned food, canned dish, acidic food Grains, vegetables, meat, molluscs Fish, mushrooms
27
Contaminants of Biological Origin(Inherent Plant
Food Toxicants)
CHEMICAL Oxalates Glycoalkaloids Cynide Phytohaemagglutinin Various carcinogens ASSOCIATED FOOD Tea White potato (solanine) Cassava, Lima beans Red kidney beans and other beans Herbs, spices
28
Contaminants of Biological OriginMycotoxins
CHEMICAL Aflatoxin Trichothecenes Ochratoxin A Ergot alkaloids Patulin Zearalenone SOURCE Aspergillus flavus and A. parasiticus Mainly Fusarium spp A. ochraceous Claviceps purpurea Penicillium claviforms Fusarium spp ASSOCIATED FOOD Corn, peanuts, copra, milk Cereals and other foods Wheat, corn, barley Barley, wheat Apples and other fruits Cereals, oils, starch
29
Minimum Water Activity for Growth of Toxigenic
Moulds
Mould Aspergillus flavus Aspergillus ochraceus Penicillium griseofulvum Minimum Aw 0.81 0.78 0.83
30
Target Organs of Some Mycotoxins
Mycotoxin Aflatoxin Ochratoxin Trichothecenes Ergot alkaloids Zearalenone Target Liver Kidney Mucosa Peripheral vascular system Uro-genital tract
31
Regulatory Limits for Mycotoxins in Foods
Mycotoxin Aflatoxins B and G Aflatoxin M1 Ochratoxin A Deoxynivalenol Patulin Zearalenone Limit (ppb) 0 - 50 10 1000 0 0.5 1 300 1000 4000 20 50 30 - 1000 Commodities All foods Animal feeds Milk, dairy Rice, corn, barley, beans, pork kidney Wheat Apple juice All foods
32
Regulatory Limits for Aflatoxins in Some Asian
Countries
Country China Hong Kong India Japan Malaysia Philippines Singapore Sri Lanka Thailand Limit (ppb) 50 20 15 30 10 10 20 Absence 30 20 Commodity Peanuts Peanuts Other foods All All All All All Peanuts All
33
Other Toxicants of Biological Origin
Chemical Ciguatera Shellfish toxins Paralytic, neurotoxic, diarrheic and amnesic Pyrrolizidine alkaloids Histamine Source Dinoflagellates Dinoflagellates Various toxic plants Spoilage bacteria Associated Food Tropical fish Shellfish Cereals, honey Fish, cheese
34
Contaminants Produced During Processing