Introduction
Mr. Ali is experiencing itchiness on his hand after a few minutes using pesticide in his garden. Such phenomenon is often heard on media, documentaries and so on.
Mishandling of chemical substances will end up in an accident such as spillage, explosion, and chemically-related diseases as well.

Know Your Chemical

• Route entry There are 5 routes of entry chemical substance into the body :

1. Inhalation : This is the most significant route of entry compared to the other.  Chemical in all sort of namely droplets, gaseous, vapours, mist penetrates into alveoli.  It then carried to the organs through blood circulation system.
   
2. Skin absorption and membrane layers.  A chemical substance in solid, liquid, vapours, aerosol or chemical fumes can be absorbed into the body through skin contact or sometimes be named dermal exposure.
   
3. Eye absorption: Chemical like toluene can penetrate the outer layer of the eyes and soon transported to body organs (liver, heart, kidney) via the eyes nerve.
4. Transplacental absorption :The foetus comes into contact with the chemical substance through the transplacental process.
   
5. Ingestion : This is not the major route of the chemical method of entry. It is associated with poor personal hygiene. Eating with unwashed hand after handling chemical can transfer the chemical through the mouth.

Chemical substances which got inside the body will be in the blood circulation system. From thereon it will be circulated to multi-organs like the liver, kidney, cerebral nervous system, blood, skin, heart, and lung. The role of the lung is to detoxify the chemical into a harmless substance (metabolism).  The process of metabolism will produce a more toxic chemical substance.

• The excretion of chemical substance
  The chemical substance in the body will be excreted out through urine, faeces, respiration, perspiration and lactation.
• Two category of chemical substance.
  The chemical is divided into two large group namely organic chemical and non-organic chemical. The organic chemical contains carbon and hydrogen while non-organic chemical does not have carbon compound.
• Chemical poisoning prevention
  

1. Elimination
   Eliminate the use of products that have a high level of chemical toxicity. Eliminate the process of chemical handling that exposes the worker to the chemical hazard.
2. Substitution
   Substitute the use of high toxicity chemical to low toxicity. This will reduce the magnitude of hazard to the user.
3. Engineering control
   • Use mechanical device while dealing with chemicals.
   • The local exhaust ventilation at the chemical point
     source.
   • Install natural or mechanical ventilation to reduce the chemical concentration at the workplace.
4. Administration control
   • Training of chemical use.
   • Dissemination of chemical information to the staff. Example: pamphlet, training, Chemical Safety Data Sheet (CSDS), Safety Operation Procedure (SOP).
   • Place appropriate chemical warning signages.
     
5. Personal protection equipment (PPE)

Wear appropriate PPE. Eg overall, nitrile glove, eye goggle, safety boot, apron.

Exposure risk 

• Below are the categories of chemical risk exposure:
  

  NO	RISK	EXPLANATION
  1	Acute	High dose of exposure within a short period of time. Immediate effect. Eg. Scan irritation.
  2	Chronic	Continuous or repeated exposure over months or years with a low dose.
  3	Reversible (temporary)	An effect that disappears if exposure to the chemical ceases.
  4	Irreversible (permanent)	An effect that has a lasting, damaging effect on the body, even if exposure to the chemical ceases.
  5	Local	The chemical causes harm at the point of contact or entry
  6	Systemic	The chemicals enters the body, is absorbed and transported to the various organs of the body.

   

• Below are the health effect caused by chemical:
  

  HEALTH EFFECT	DETAILS	EXAMPLES
  Irititans	Chemicals may cause local irritation or inflammation to the eyes/skin/nose or respiratory system tissue. These effects are often reversible	Nitorgen oxides, sulphur dioxide, formaldehyde
  Sensitizer	Chemicals may cause or initiate an allergic reaction. How long the effect will occur depending on the individual susceptibility to the chemical	Toluene di-isocyanate, nickel at chromium compounds
  Corrosive	Chemicals that may destroy or deteriorates living tissue upon contact	Asid sulphuric, sodium hydroxide
  Hepatotoxins	Chemicals that may damage the liver	Carbon tetrachloride, chloroform
  Nepthrotoxins	Chemicals that may damage the kidney.	Halogenated hydrocarbon, lead, uranium, cadmium
  Neurotoxins	Chemicals that may damage the nervous system	Mercury, carbon disulphide
  Narcotic	Chemicals that may depress the central nervous system and it is fatal	Acetone, xylene, chloroform, ethyl ether
  Carcinogen	Chemicals that causes cancer	Acrylonitrile, asbestos, arsenic, benzene
  Mutagen	Chemical that may causes permanent damage to the DNA in a cell	Dioxin, mercury, chloroprene, ionizing radiation
  Teratogen	Chemicals may cause birth defects	Plumbum, formamides, methyl mercury
  Asphyxiation	Chemical that may interfere with the ability of living tissue to absorb oxygen	Carbon dioxide, nitrogen, helium, carbon monoxide, hydrogen cyanide

   

References

1. Ashafl, C. R., Rieske, D. W. (2010). Industrial Safety & Health Management (6th ed.). Prentice Hall.
2. Chemical Hazard and Alternative Toolbox. (n.d.). Benzaldehyde. Diambil dari: http://www.chemhat.org/en/chemical/100-52-7/benzaldehyde (Diakses pada 18/11/2015).
3. Chemical Safety. (2001). Malaysian Institute for Nuclear Technology Research (MINT). Bangi, Kajang.
4. Chemical Safety. (2012). Open University of Malaysia.
5. Ronald Scott (1997).Basic concepts of Industrial Hygiene. Francis and Taylor.
6. Sunil S.R., & Jain, R.K. (2015). Industrial Safety, Health and Environment Management Systems. Delhi, IND: Khanna Publishers.