Chemical safety Topic 1

• Safety signs


  Crucial in any workplace, important hazard communication tools, convey potential hazards and precautions to be taken, use graphical symbols, must be maintained in good condition
• Standardisation of safety signs

  Standardize a system of giving safety information, use as few words as possible to achieve understanding, require a common method of communicating safety information due to growth in international trade, travel & mobility of labour, lack of standardization may lead to confusion & risk of accidents
• ISO standards for safety signs

  ISO 3864 - Graphical symbols – Safety colours and safety signs, ISO 17724:2003 - Graphical symbols – Vocabulary (terms and definitions), SS 508:Part 5:2013+A1: 2016 (ISO 7010 : 2011)
• Categories of safety signs

  • E - Safe Condition Sign, F - Fire Safety Sign, M - Mandatory Action Sign, P - Prohibition Sign, W - Warning Sign
• E - Safe Condition Sign

  Green square with white symbols, identify evacuation route & assembly points, indicate location of first aid & emergency equipment or a safety facility or action
• E - Safe Condition Signs

  • Evacuation assembly point (E007), Emergency exit (right hand) (E002), First aid (E003), Emergency telephone (E004), Automated external heart defibrillator (E010), Eyewash station (E011), Safety shower (E012)
• F - Fire Safety Sign

  Red square with white symbol, and always include representation of flames in white, indicate the location of fire equipment
• F - Fire Safety Signs

  • Fire extinguisher (F001), Fire hose reel (F002), Fire alarm call point (F005), Fire emergency telephone (F006), Fire protection door (F007), Fire blanket (F016)
• M - Mandatory Action Sign


  Blue circle with white symbol, specifies an action required to safeguard personal health and/or avoid risk or personal injury
• M - Mandatory Action Signs


  • General mandatory action sign (M001), Refer to instruction manual/booklet (M002), Wear ear protection (M003), Wear eye protection (M004), Wear safety footwear (M008), Wear protective gloves (M009)
• P - Prohibition Sign


  Red ring and diagonal bar with black symbol on white background, specifies behaviour that is prohibited because it would result in an immediate or potential risk of personal injury or threat to health
• P - Prohibition Signs


  • General prohibition sign (P001), No smoking (P002), No open flame; Fire; open ignition source and smoking prohibition (P003), Not drinking water (P005), Do not touch (P010), No eating or drinking (P022)
• W - Warning Sign

  Yellow triangle with black border and black symbol, warns of hazards which could result in personal injury or threat to heath, accompanied by text or additional signs to explain reasons for warning
• W - Warning Signs

  • General warning sign (W001), Warning; Explosive material (W002), Warning; Radioactive material or ionizing radiation (W003), Warning; Laser beam (W004), Warning; Non-ionizing radiation (W005), Warning; Slippery surface (W011), Warning; Biological hazard (W009)
• Purpose of GHS


  Helps to get every country on the same page for chemical regulations & standards, facilitate international trade by ensuring that all chemicals moving into and out of a country are classified, packaged and labelled in accordance with GHS, enhance protection of humans & environment against hazardous chemicals
• GHS adopted by Singapore in 2002, Singapore Standard SS 586 introduced in 2008
• GHS Hazard Classification


  • Chemicals are classified into different classes or categories based on their physical properties (Physical Hazard), health effects or toxicity (Health Hazard), and environmental toxicity (Environmental Hazard)
• GHS Pictograms


  • Explosive, Flammable, Oxidizing, Compressed Gas, Corrosive, Toxic, Health Hazard, Environmental Hazard, Skull and Crossbones
• Flammable Substances


  Organic or inorganic materials that can easily be ignited & result in fire, flash point is the lowest temperature at which a liquid gives off sufficient flammable vapour to ignite in the presence of an ignition source
• Hazard Classification of Flammable Liquids

  • Cat 1: Flash point < 23 oC and initial boiling point ≤ 35 oC, Cat 2: Flash point < 23 oC and initial boiling point > 35 oC, Cat 3: Flash point ≥ 23 oC and ≤ 60 oC, Cat 4: Flash point > 60 oC and ≤ 93 oC
• Pyrophoric Substances


  Chemical that can ignite spontaneously in air at a temperature below 130oF (54.4oC) or below, must not be exposed to the atmosphere, improper handling can result in serious injury such as serious burns
• Oxidising Substances


  Substance that may cause or contribute to combustion, readily gives off oxygen & other oxidizing substances, speed up the development of a fire
• Corrosive Substances


  Substance that is capable of causing visible destruction or irreversible changes in human skin tissues at the site of contact or degrade other materials (metals) upon contact, acids & bases are common corrosive materials
• Gases Under Pressure


  Consists of compressed, liquefied, refrigerated liquefied & dissolved gases, poses physical hazard due to its size & weight, high pressure inside cylinder, and varying chemical properties of gases
• Properly secure gas cylinders


  Chained individually to the wall bracket or other fixed & stable structure, or use a cylinder stand
• GHS Hazard Communication


  Consist of GHS Safety Datasheet (SDS), GHS Labels & Training, aim to identify intrinsic hazards of chemicals & convey hazard information about each hazard class & category, take necessary precautions to ensure safe use & /or handling of chemicals
• GHS Safety Data Sheet (SDS)


  Document with standard format - 16 information items in sequence, serves as a hazard communication tool, user can obtain key information on identity of chemical, hazard associated, preventive measures, and emergency measures
• SDS required for every chemical substance or product, suppliers shall periodically review the information on label & SDS every 5 years, user has to regularly review SDS collection in laboratory & replace SDS > 5 years
• GHS Label


  Key element in harmonized hazard communication, communicate to user the identity of chemical, hazard involved, and precautionary measures, 7 information items required
• All packaging / containers containing hazardous substances must be affixed with one a full GHS label in accordance with SS 586 requirements, in language easily understood by all users or workers, recommended dimension of GHS label
• Reduced workplace label


  Where full GHS label is not practicable, shall consist of product identifier (name) and GHS pictogram(s)
• Personal Protective Equipment (PPE)


  • Identify, select and use appropriate PPE to handle chemicals
• Factors to consider for chemical storage and compatibility


  Properties of chemicals, chemical incompatibility, storage quantity, operational & environmental conditions, refer to SDS
• General chemical storage rules

  • Store chemicals in compatible groups, segregate incompatible chemicals, store chemicals in a cool, dry, well-ventilated area, label all containers, keep containers closed when not in use, store chemicals at appropriate height, all hazardous chemicals must be locked
• Reduced workplace label


  Shall consist of: Product identifier (name), GHS pictogram(s)
• Factors to consider for chemical storage and compatibility


  • Properties of chemicals
  • Chemical incompatibility
  • Storage quantity
  • Operational & environmental conditions
• General Chemical Storage Rules

  1. Sort & separate chemicals – Inorganic or Organic

  2. Segregate into compatible storage groups

  3. Store in alphabetical order within compatible group
• All hazardous chemicals must be locked (SGSecure)
• How to organise Chemical Compatibility?

  1. Step 1: Sort & separate chemicals – Inorganic or Organic

  2. Step 2: Segregate into compatible storage groups

  3. Step 3: Store in alphabetical order within compatible group
• Separating organic from inorganic chemicals