Atoms and Molecules

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Global Consumer Science
IJSO Training (Phase 2)
Dr. Kendrew K. W. Mak
Department of Chemistry
The Chinese University of Hong Kong
1
Consumer Products are Used in
Every Aspect of Our Daily Life
Composed of an array of personal care and household products that
are used for personal, family, or household purposes.
Such as:
IT and electronic products
Personal care products
Food and beverage (including packaging)
Household cleaning products
Furniture
Fabrics and clothing
etc......
2
Consumer Products
Ideal design of consumer products:
•
Fit to the designated purpose
•
Safe to the consumer
•
Safe to the environment
•
Minimize resource consumption in the production
•
Minimize waste production
3
Impacts of Consumer Products
Health
•
•
•
•
Environmental pollution leading to health problems
Toxic ingredients
Problems related to inappropriate diet and nutrition.
Injuries resulted from using the badly designed products.
Environmental
•
•
•
•
•
•
Air pollution
Noise pollution
Water pollution
Waste production
Non-degradable solid waste, toxic waste
Affecting the ecology
4
Impacts of Consumer Products to
the Environment
• Depleting the world’s (non-renewable-不可再生的) resources
e.g. use of petroleum for fuel and producing raw materials
mineral mining for producing metal products and fertilizers
• Pollution
e.g. air pollution (airborne particle, acid rain, VOC…)
water pollution (heavy metal, nutrients, organic toxin)
ozone depletion (消耗臭氧)
• Waste Disposal
e.g. non-degradable solid waste (plastic)
domestic hazardous waste (medication, paints, batteries…)
non-degradable – 不可降解的
5
Depleting the World’s
(non-renewable) Resources
Activities leading to resource depletion:
• Farming – land/soil/nutrient depletion
• Fishing – extinction of certain species
• Mining – depletion of oil and mineral resources
• Timber industry – depletion of woodland, desertification
World oil consumption (1965 – 2005)
6
Air Pollution - VOCs
Volatile organic compounds (VOCs) are organic compounds that are
easily vaporized under normal conditions and contaminate the
atmosphere.
Source of VOCs:
Paint thinners (油漆稀釋液), dry cleaning solvents, petroleum fuels,
aerosol sprays (噴霧劑), pesticides (農藥), air refreshers (空氣清新劑),
perfumes (香水), etc.
Soil and groundwater contamination (accidentally released)
Escaped VOCs - cause air pollution
Volatile organic compounds – 揮發性的有機化合物
7
Water Pollution – Eutrophication
(富養化作用)
Eutrophication – The process by which a body of water become
enriched in dissolved nutrients (usually phosphates or nitrogen
containing compounds) that stimulate the growth of aquatic plant
life. It causes depletion of dissolved oxygen in water.
Sources of Pollutants
Phosphorus (磷) and nitrogen (氮) runoff from detergents or fertilizers.
Phosphates (磷酸鹽) were added to laundry detergents (洗衣粉)
as builders (助潔劑) to enhance the surfactant effects (表面活化
作用).
Between 1940 and 1970 the amount of phosphates in city
wastewater increased from 20,000 to 150,000 tons per year.
Algal blooms grew on the excess phosphorus and consumed the
oxygen in water, killing fish and plants.
8
Ozone Depletion – CFCs
Increased damages to
• Human immune system (人體免疫系統)
• Skin
• Ecology
Cl
CFCs used in:
Cl
C F
Cl
Trichlorofluoromethane (三氯氟甲烷)
Freon-11, CFC-11
Refrigerants (製冷劑)
Propellants for aerosol spray (氣霧推進劑)
Fire extinguisher (滅火劑)
Chlorofluorocarbons (CFC) – 氯氟碳化合物
9
CFC (Chlorofluorocarbons) as
ideal refrigerants
CCl2F2 Dichloro-difluoromethane (二氯二氟甲烷)(CFC-12)
An almost ideal refrigerant:
Stable and chemically inert
Non-toxic, non-flammable, and non-corrosive
Physical properties very suitable for the application
Very inexpensive
hv
CClF2
CCl2F2
+
Cl
Cl
+
O3
ClO
+
O2
ClO
+
O3
Cl
+
O2
A chain radical reaction leading to the destruction of ozone.
10
Newer Refrigerants
Cl
F
H C F
H
H
C F
Cl
Chlorodifluoromethane
HCFC-22, R-22
Difluoromethane 1,1,1,2-tetrafluoroethane
HFC-32, R-32
HFC-134a, R-134a
Hydrochlorofluorocarbons (HCFCs)
The environmental effects are
only about 10% of the CFCs
F F
H C C F
H F
Hydrofluorocarbons (HFCs)
Even more environmental friendly
11
Municipal Solid Waste (MSW)
Municipal solid waste (都市固體廢物) is a waste type that includes
predominantly household waste (domestic waste – 家居廢物) with
sometimes the addition of commercial wastes collected by a
municipality. They are in either solid or semisolid form and
generally exclude industrial hazardous wastes.
Consumer packaging 消費品包裝
The packaging of goods sold to consumers.
(shopping bags, packaging bags, boxes and gift wraps, bottles,
Tetrapak paper packages……)
Industrial packaging 工業產品包裝
For protection and transportation purposes.
(PS foam, air-bubble sheets, cartons…..)
Packaging wastes contribute to about 20% of the solid waste.
12
Solid Waste Management
(固體廢物之管理/處理)
Source Reduction (減少廢物產生)
Altering the design, manufacture processes, or materials used to
reduce the amount and toxicity of what gets thrown away.
Recycling (回收 / 循環再造)
Divert items, such as paper and plastics, from the wastestream.
These materials are sorted, collected, and processed and then
manufactured, sold, and used as new products.
Composting (堆肥)
Decompose organic waste, such as food scraps and yard trimmings
with microorganisms (bacteria and fungi), producing a humus-like
substance.
Combustion (焚化)
Burning of municipal solid waste to reduce the quantity of waste
that needed to be disposed of in landfills.
Land filling (堆田)
Waste is dumped into the land
13
Reduce and Reuse (減少及重用)
• Purchasing durable, long-lasting goods
• Seeking products and packaging that do not contain toxic
substances
• Redesigning products that use less raw material in production,
have a longer life, or can be used repeatedly.
Examples
• Use non-disposable tableware and cutlery
• Use rechargeable batteries
• Reduce the use of shopping bags
• Use refillable items (pens, household/body care liquid products……)
14
Recycling (循環再造)
Examples of Recyclable Materials
• Batteries
• Plastic
• Biodegradable wastes (food waste)
• Printer ink cartridges and toners
• Metals
• Paper
15
Recycling of Plastics
Most plastics can be recycled, but they have to be separated into
different types according to the Resin Identification Code (塑膠
分類標誌).
Code
Abbreviation Polymer name
Recycled to produce (examples)
PETE or PET Polyethylene
terephthalate
Polyester fibers and soft drink
bottles.
HDPE
High density
polyethylene
Milk bottles, bottles for
household cleaners,
playground equipment
PVC or V
Polyvinyl
chloride
Pipe, fencing, raincoats
LDPE
Low density
polyethylene
Plastic bags, dispensing bottles,
tubing, food wraps
16
http://en.wikipedia.org/wiki/Resin_identification_code
Recycling of Metals
Aluminium soft-drink cans (汽水鋁罐)
• Most soft-drink cans are made of aluminium.
• An aluminium can is 100% recyclable.
• Aluminium is cut into small pieces and melted to produce molten
aluminium for further processing.
• Hugh amount of energy is required to extract aluminium from ore.
• Recycled aluminium is indistinguishable from those obtained from
ore.
17
Composting of Biodegradable
Substances
Biodegradable waste (可被生物降解之廢物) can be recycled into
useful material by biological decomposition (生物降解作用).
Composting is the
process of producing
compost through aerobic
decomposition of
biodegradable organic
matter.
http://hk.news.yahoo.com/070618/12/29rbv.html
18
Avoid Using Non-biodegradable
Materials
Modern technologies turned many natural substances into new
materials which cannot be easily broken down by microorganisms
(微生物) and enzymes (酶).
Example: Petroleum can undergo biodegradation slowly, but most
plastic (which are made from petroleum) cannot.
Conventional, non-biodegradable polymers
CH2
CH2
CH
CH
CH2
CH
CH2
CH
CH2
CH
CH
CH2
CH2
CH
n
Cl
Poly(vinyl chloride) (聚氯乙烯)(PVC)
Polystyrene (PS)
H H H H H H H H H H H
C C C C C C C C C C C
H H H H H H H H H H H
Polyethylene (PE)
19
Degradable Plastics
Degradable
Polymer
Degradation
(降解)
- Photochemical decomposition
(光化學分解)
- Hydrolysis
- Oxidation
- Biochemical degradation
Faster Degradation
Smaller Polymer Fractions
(Increased Surface Area)
CO2 and H2O as final products
20
Examples of Biodegradable Plastics
Polyethene incorporated with starch
- mixed with 6 - 40% of starch.
Starch content higher than 9%
- degrade within 1 year under favorable conditions.
Useful for making biodegradable grocery bags.
21
Renewable Resources – Biodiesel
Biodiesel is a type of fuel made from vegetable oil that can be
used in unmodified diesel engine.
glycerol part
(甘油部份)
H
O
H C O
C
H C O
C
O
H C O
H
C
O
fatty acid parts
(脂肪酸部份)
Triglycerides (三酸甘油酯)
(Esters of glycerol with long-chain fatty acids)
22
Renewable Resources – Biodiesel
glycerol part
H
H C O
H C O
H C O
H
O
O
C R1
C R2
O
Methanol
Sodium hydroxide solution
(甲醇、氫氧化鈉溶液)
C R3
O
t ransesterif icat ion
(轉酯化反應)
H
H C OH
H C OH +
H C OH
H
glycerol
R1
R2
R3
C
O
C
O
C
OCH 3
OCH3
OCH 3
fatty acid portions
Methyl esters of fatty acids
(甲基油酸)
Biodiesel
23
Ethanol as Car Fuel
Biomass as Renewable Sources of Useful Chemicals
Wood, Cotton
Corn, Wheat, Rice
Canes
Cellulose
Starch
Sucrose
O
HO
OH
OH
OH
O
OH
O
O
HO
O
OH
O
n
O
HO
HO
HO
n
OH
O
O
HO
CH2 OH
OH
OH
HO
HO
CO2 Recycling
Fermentation
O
OH OH
C 2 H5 OH
Ethanol
24
Wayman, M.; Parekh, S. R. Biotechnology of Biomass Conversion, Open University Press, Milton Keynes, 1990.
Ethanol as Car Fuel
• In 2004, 44% of the vehicle fuel used in Brazil was ethanol.
• Between 1983-1988, over 90% cars sold were ethanol-only cars.
• 80% of the cars produced in Brazil in 2005 were dual-fuel.
• Bagasse (the fibrous material left over from pressing) are used to
provide electricity for the distillery
25
How Foods (Crops) Are Improved
In the past – Selective Breeding (~ 10 Years)
In the past, farmers improved crops and domestic animals by
breeding for desirable traits. This process is often uncertain and
very time consuming.
Now – By Genetic Engineering (~ 1 Years)
Now scientists can use the tools of modern molecular biology to
introduce genes from desired traits into plants and animals.
The resulting organisms are called transgenic organisms because
they contain genes from another species.
26
Genetically Modified (GM) Foods
Genetically Modified (GM) foods (基因改造食物) are produced from
Genetically Modified Organisms (GMO)
To produce a genetically modified organism, DNA that has been
taken from another organism and modified in the laboratory is
inserted to the organism to produce new and useful traits.
Examples of GM Foods
• Tomato (Flavr Savr, delayed ripening)
• Soybeans (Roundup Ready, herbicide-tolerant)
• Maize (insect-protected, herbicide-tolerant)
• Rice (Golden rice, produce beta-carotene)
27
http://en.wikipedia.org/wiki/GM_food#Abundance_of_GM_crops
Flavr Savr Tomato
The first commercial grown genetically engineered food for human
consumption. The tomato was made more resistant to rotting.
Flavr Savr Tomato
Ripe and increased
Flavor
Ripens on the vine,
resulting in fuller flavor.
Traditional
Spray with ethylene
after shipping to
induce ripening
Harvest while green
and firm, easier for
transportation
Ripe but decreased
Flavor
28
Insect-Protected Maize
(a) Bacillus thuringiensis (Bt) is a bacterium that produces proteins which
are toxic to corn pest.
(b) Inserting the gene that responsible for producing Bt proteins into corn’s
DNA.
(c) The GM corn can produce Bt proteins, so becomes resistant to the pest.
29
Rice (Golden-rice)
Golden rice is a kind of rice produced through genetic
engineering that contains the precursor of beta-carotene (provitamin A) in the edible part of rice.
Vitamin A Deficiency (VAD)
Affected 124 million people
118 countries (Africa / South-East Asia)
Annually:
1-2 million death
500,000 irreversible blindness
30
Genetically Modified Food
Controversies
The GM food controversy is a dispute over the advantages and
disadvantages of genetically modified food crops.
Some advantages of introducing GM foods
• Increase crop yield – feed more people and reduce famine.
• Reduce the use of synthetic insecticides – protect farmers,
consumers, and the environment.
• Producing food with higher nutrition values (protein-enriched
potatoes, golden rice), particularly helpful to developing countries.
• Herbicide-resistant crops (Round-up Ready crops) – better
protection for crops’ quality and quantity
31
Genetically Modified Food
Controversies
Worries about GM foods
• Trigger allergic reactions
• Create new, potential harmful foods / substances
• Disturb the balance of ecosystems, biodiversity. (Pollen from Bt
corn may have adverse effects on beneficial insects)
• Development of pesticide-resisting, super pests
• Increased use of herbicides – fewer weeds – impact on the
wildlife.
32
Consumer Product Testing
(消費品測試)
- the evaluation of goods sold in the retail
marketplace
Why do consumer products need testing?
Safety
Quality
33
Consumer Product Testing
News: (safety)
News from Internet and
newspaper about the safety of
consumer products such as
toys, batteries for portable
computers, cars … etc.
34
Consumer Product Testing
Benefits to Manufacturer
•
Products comply to applicable regulations
•
Products look and function as intended
•
Assess the performance of products against a competitor’s
products
•
Enhance risk management and protect the company’s
brand
•
Determine whether the products will be damaged during
transport
Benefits to Consumer
- Faith and safe to use
35
Consumer Product Testing
Who are going to do the consumer product testing?
Manufacturers
Government Bodies
Commercial Testing
Laboratories
Consumers
36
Consumer Product Testing
Manufacturers (生產商)
Quality Control Laboratory (品質控制實驗室)
- check regularly the quality of the products
37
Consumer Product Testing
Government Bodies (Local)
- regularly checking on the products to see whether
they are safe to use.
Government Laboratory (政府化驗所)
Food and Environmental Hygiene Department
(食物環境衛生署)
Consumer Council (消費者委員會)
38
Consumer Product Testing
Commercial Testing Laboratories
- independent third party testing services
CMA Testing and
Certification
Laboratories
ITS Intertek Testing
Services
It the laboratory is accredited, some of their tests will
be recognized internationally.
No duplicate testing!
39
Consumer Product Testing
Consumers
Can you do your own consumer product testing?
Story about the Ribena with which
in 2004 two high school students
from New Zealand conducted a
science experiment to determine
the Vitamin C levels of their
favourite fruit drinks.
40
Consumer Product Testing
Example: Lighter Safety Test
BS EN ISO 9994:2006 “Lighters-Safety Specification”
-
define the quality, reliability and safety of lighters with
test procedures
Functional Requirements
-
Flame generation
-
Flame heights
-
Flame height adjustment
-
Resistance to spitting or sputtering and flaring
-
Flame extinction
41
Consumer Product Testing
Structural Integrity Requirements
-
External finish
-
Compatibility with fuel
-
Resistance to fuel loss
-
Resistance to dropping
-
Resistance to elevated temperature
-
Resistance to internal pressure
-
Burning behaviour
-
Resistance to cyclic burning
-
Resistance to continuous burning
42
Consumer Product Testing
Example:
Quality of Honey
Conducted by Consumer Council (HK) & the
Consumers Korea
CODEX Standard: internationally use
Sucrose content:
<5%
(Food & Drugs (Composition & Labeling) Regulations)
(Hydroxymethylfurfural)
HMF level (an indicator of freshness): <40mg/kg
Moisture Content:
<20%
http://www.consumer.org.hk/website/ws_en/news/press_releases/p35903.html
43
Consumer Product Testing
(抽濕機)
Example: Comparative Test of Dehumidifiers:
by the Consumer Council
10 models claim to have capacity ranging from 20L to 25L
moisture a day.
Conditions for rating:
8 models
30oC
80% (RH)
2 models
32oC
80% (RH)
More realistic measurement:
Test condition:
26.7oC
60%
(US Association of Home Appliance Manufactures standard)
44
Consumer Product Testing
Similar test condition: 27oC
60%
Standards use in Japan, China, Europe and Taiwan
Results of 10 models:
- ranging from 5.61L to 13.24L per day.
In Hong Kong, no mandatory standard test conditions for
rating dehumidifying capacity of household portable
dehumidifiers at present.
http://www.consumer.org.hk/website/ws_en/news/press_releases/p34101.html
45
Consumer Product Testing
Toy Testing:
(玩具測試)
Different countries or regions have different standards.
Europe:
EN71, …
USA:
ASTM F963, …..
Australia:
AS1674, …..
Canada:
Canada Hazardous Products (Toys)
Regulations & Act
46
Consumer Product Testing
EN71:
Part 1: Physical & Mechanical Tests
i. Torque and tension (扭力-拉力測試)
ii. Drop Test
(跌落測試)
iii. Impact Test
(撞擊測試)
iv. Compression Test
(壓力測試)
47
Consumer Product Testing
EN71:
Part 2: Flammability Test (易燃性測試)
Photos on Flammability Test
48
Consumer Product Testing
EN71:
Part 3: Toxic Elements Test (有毒物質測試)
Antimony (Sb), Barium (Ba), Cadmium (Cd),
Chromium (Cr), Lead (Pb), Mercury (Hg),
Selenium (Se) and Arsenic (As)
- migration of elements from samples in the experimental
environment similar to human digestion system.
Sample cut into very small size and put into container with 0.25%
HCl. Shake 1 hour and stand for 1 hour before analysis of the
heavy metals.
(Prepare one sample for one color)
49
Consumer Product Testing
EN71: Part 4: Experimental Set for Chemistry
Part 5: Chemistry Toys (Sets) Other than
Experimental Sets
Part 6: Graphical Symbol for Age Warning Labeling
Part 7: Finger Paints
EN50088 – Electric Toy Safety Test
EMC Directive 89/336/EEC: EMI and EMS testing
Remote Control Toys:
Radio (RF) + EMC + LVD testing
Electromagnetic
Compatibility
Low Voltage
Directive
50
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