Acids and Bases, Bases and Acids, Acids

Acids and Bases

1. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Presented by:
Ms. RosaleeB. Fajilan
Senior Industrial Hygienist , Environment Control Division
Occupational Safety and Health Center
ACIDS AND BASES

2. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Outline of Presentation
Acids and Bases
❖Acids and Bases Definition and Properties
❖The Strength and Concentration of Acids
and Bases
❖The health hazards of Acids and Bases in
the workplace
❖Occupational exposure to Acids and Bases

3. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
•They are compounds...
that are fundamental to the functioning of our world
and we need them!
•They are essential to Life
In digestion – Our gastricjuice contains hydrochloricacid
breaks down the food we eat
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What are ACIDS and BASES?

4. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
•They are essential to Life;
In blood circulation – Acids and bases balance the proper
blood circulation of thebody. Blood is slightly basic.
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What are ACIDS and BASES?

5. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
In agriculture – The acidity or alkalinity of soil is
veryimportantinagriculturebecause it regulates plant
nutrient availability by controlling the chemical forms of
the different nutrients and also influences their
chemical reactions.
Lime is used to adjust
the acidity of soil
(Calcium carbonate-
CaCO3)
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What are ACIDS and BASES?

6. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
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Everyday ACIDS

7. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
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Everyday BASES

8. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Chemical formula of common ACIDs

9. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Chemical formula of Common BASES

10. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Definition according to Svante Arrhenius – a Swedish chemist
Acids
•Arrhenius acid- is a chemical compound that increases the
concentration of hydrogen ions (H
+
) in aqueous solution
Bases
•Arrhenius base - is a substance that increases the
concentration of hydroxide ions (OH
-
) in aqueous solution.
What are ACIDs and BASEs?

11. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
In aqueous solution only

12. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Definition according to Johannes Nicolaus Bronsted and Thomas
Martin Lowry
Acids
•Bronsted-Lowry acid: A proton (positive ion) donor
Bases
•Bronsted-Lowry base: A proton (positive ion) acceptor
What are ACIDs and BASEs?

13. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
•Acids and bases exist as conjugate pairs. When the acid donates a proton, it forms its
conjugate base. When a base accepts a proton, it forms its conjugate acid.
•Some compounds act as either an acid or a base, depending on the reaction.
Compounds which are both acids and bases are amphoteric.

14. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Theory of Sir Gilbert Lewis (American Chemist)
Acids
•Lewis acid: An electron (negative ion) acceptor
Bases
•Lewis base: An electron (negative ion) donor
What are ACIDs and BASEs?

15. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

16. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
What is an ACID?
•Have a sour taste.
•Change the color of acid-base
indicators (litmus paper) to red
•Reacts with metals to release
hydrogen gas
•Reacts with bases to produce
salts and water. (neutralization)
•Conducts electric current

17. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
What is a BASE?
•Tastes bitter
•Dilute aqueous solutions of
bases feel slippery. (like soap)
•Change the color of acid- base
indicators (litmus paper) to
blue.
•Bases react with acids to
produce salts and water.
•Conducts electric currents.

18. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Properties of ACIDS and BASES
•Acids generally taste sour due to the
sour Hydrogen ion(H+) that activate the
tongue's sour taste receptors
•Bases taste bitter due to the Hydroxide
ion (OH-) that activate the tongue’s bitter
taste receptors
•But they may have other tastes depending
on the other part of the molecule.

19. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Properties of ACIDS and BASES
•Acids react with most metals to
form a salt and hydrogen gas
•Bases also react with certain
metals, like zinc or aluminum,
to produce hydrogen gas

20. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Properties of ACIDS and BASES
ACIDS AND BASES CONDUCTS ELECTRICITY in its
aqueous state
•To conduct electricity, there must be charged particles.
In metals, free electrons are the charged particles which
make it possible for electricity to be conducted.
•Acids and bases, haveions.Note that they will only
conduct electricity in their aqueous state, since
theionsare mobile in this state.

21. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
ACID - BASE Indicators

22. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
ACID - BASE Indicators

23. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
ACID - BASE Indicators

24. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Other
ACID -
BASE
Indicators

25. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

26. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Properties of ACIDS and BASES

27. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

28. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

29. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
pH Scale
•A change of 1 pH unit represents a
tenfold change in the acidity of the
solution. (X 10)
•For example, if one solution has a pH of 1
and a second solution has a pH of 2, the
first solution is not twice as acidic as the
second—it is ten times more acidic.

30. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Strength and Concentration of
Acids and Bases

31. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Strength of ACIDS and BASES
➢Acids and bases are classified according to
the degree to which they dissociate (break
apart into ions) in water.
•Strong are completely dissociate (100%) in
aqueous solution
•Weak are dissociate only slightly in aqueous
solution

32. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

33. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

34. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

35. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Concentration of ACIDS and BASES
➢Concentration – How much of the acid/base are
added in a solution
•Concentrated = A LOT of acid/base molecules.
•Dilute = A little of acid/base molecules.

36. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Strength vs. Concentration
•The words Strong and Weak refer to the extent of
dissociation of an acid or base.
•Strong = complete dissociation (100%)
•Weak = partial dissociate
•The words Concentrated and Dilute tell how much of
an acid or base is dissolved in solution – refers to the
number of moles of acid or base in a given volume

37. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Health Hazards of
Acids and Bases

38. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Acids and Bases
Exists as Mist in the Work Environment
❖Dispersion of liquid particles in the air.
❖Suspended liquid droplets when vapor
condenses back to a liquid

39. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Exists as Mist in the Work Environment

40. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
•Concentrated acids and bases are corrosive
and cause chemical burns if they come into
contact with the skin, eyes or internal organs.
Acid burns usually cause immediate pain and
tissue damage.
•You may not notice right away if your skin
contacts a base. Since the pain is delayed,
this may mean your skin is exposed for a
longer time.
Hazards of Acids and Bases
Contact Hazards

41. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Hazards of Acids and Bases
•Many acids and bases
are highly toxic by
inhalation.
•The airborne mist will
irritate the mucous
membranes of the
nose, throat and lungs.
Respiratory Hazards

42. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
•When acids or bases are mixed with
other chemicals, combustion can occur.
•In general, acids react with metalsto
give salt and releasehydrogen gas. In
general,bases donotreact with
metalsand releasehydrogen gas.
•Never work with acids and bases while
smoking or using open flames, such as a
Bunsen burner.
Hazards of Acids and Bases
Fire Hazards

43. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Occupational Exposure to
Acids and Bases

44. Occupational Exposure
➢Wastewater treatment
Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Commonly used
➢Hydrochloric acid
➢Sodium hydroxide

45. Occupational Exposure
Electroplating in Electronic and Semiconductor
Industry
Commonly used
➢Hydrochloric acid
➢Sulfuric acid
➢Nitric acid
Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Acidsand bases makes the bath
conductive and acts as a charge
carrier.

46. Occupational Exposure
Car Batteries
➢Battery acid is
sulfuric acid that
has been diluted
with water to
attain a 37%
concentration
level.
Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
➢Battery acid is the
medium
thatcarries the
electrical flow
between positive
and negative
electrodes

47. Occupational Exposure
Alkaline Batteries
➢Potassium Hydroxide or
➢Sodium Hydroxide
Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Alkaline potassium hydroxide act as electrolyte

48. Occupational Exposure
Phosphoric acid and Carbonic acid in
softdrinks manufacturing
Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

49. Occupational Exposure
Cleaning and
Disinfection Chemicals
➢Sodium Hydroxide in soaps -
basic
➢Chlorine solution – acidic
➢Ammonia in glass cleaners
and other household cleaners
- basic
➢Sodium Hydroxide or
Potassium Hydroxide – drain
declogger
Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER

50. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Phil. Regulations on
Acids and Bases

51. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
OSHS and Acids and Bases
RULE 1090 – Hazardous Materials
➢Rule 1094 – Hot and Corrosive Substances
➢1094.01 – Handling
➢1094.03 – Spillage of Acids and Alkalies
➢1094.04 – Diluting Acids
➢1094.05 - Physical Contact with Corrosive Substances
➢Rule 1095 – Storage
➢1095.01 – Vats and Tanks
➢1095.02 – Storage Tanks for Non-Flammable Hazardous Liquids
➢1095.03 – Drums containing Acids
➢1095.04 – Carboys for Acids

52. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Controlled Acids and Bases
By the Phil. Drug Enforcement Agency (PDEA)
Under R.A. 9165 or “The Comprehensive
Dangerous Drugs Act of 2002”
➢Hydrochloric Acid
➢Sulfuric Acid
➢Phenylacetic Acid
➢N-Acetylanthranilic Acid
➢Anthranilic Acid
➢Lysergic Acid

53. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Controlled Acids and Bases
By the Phil. National Police (PNP)
Under R.A. 9516 “AN ACT FURTHER AMENDING THE
PROVISIONS OFPRESIDENTIAL DECREE NO. 1866, AS AMENDED,
ENTITLED CODIFYING THE LAWS ON ILLEGAL/UNLAWFUL POSSESSION,
MANUFACTURE, DEALING IN, ACQUISITION OR DISPOSITION OF
FIREARMS, AMMUNITION OR EXPLOSIVES OR INSTRUMENTS USED IN
THE MANUFACTURE OF FIREARMS, AMMUNITION OR EXPLOSIVES, AND
IMPOSING STIFFER PENALTIES FOR CERTAIN VIOLATIONS THEREOF,
AND FOR OTHER RELEVANT PURPOSES"
➢"SEC. 4-D.Types of Chemicals/Accessories Covered. - The
chemicals and accessories mentioned in the preceding Section shall
exclusively refer to chlorates, nitrates, nitric acid and such other
chemicals and accessories that can be used for the manufacture of
explosives and explosive ingredients.

54. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Clear Points:
Similarities of ACIDS and BASES
➢Dissolve in water
➢Conducts electricity
➢Can irritate or burn skin

55. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Differences of ACIDS and BASES
Clear Points:

56. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Clear Points:
➢Acids and bases have many industrial
uses.
➢They are extremely dangerous if not
properly handled and controlled.

57. Department of Labor and Employment
OCCUPATIONAL SAFETY AND HEALTH CENTER
Thanks for listening…
Environment Control Division
Email: [email protected] / [email protected]
Telefax No: (02) 8924 – 24 – 12