PHY1509 Assessment 2 full solutions 2026
UNISA
2026
All questions are answered and verified align with marks allocations
, QUESTION 1
1. Why normal clothes are insufficient as a substitute for a lab coat
Normal everyday clothing does not provide adequate protection in a chemical
laboratory. According to the University of South Africa (2026), a lab coat must be knee-
length, made of cotton, and kept fully buttoned with sleeves unrolled at all times during
laboratory work. This design creates a protective barrier specifically engineered to resist
chemical splashes and spills that would otherwise penetrate ordinary fabric and
contact the skin directly.
Ordinary clothing, particularly synthetic fabrics, presents additional dangers. As noted
by the University of South Africa (2026), synthetic materials may melt or ignite when
exposed to heat or open flame, whereas a cotton lab coat offers greater thermal
resistance. Furthermore, street clothing cannot be removed rapidly in an emergency,
whereas a lab coat can be quickly discarded to minimise chemical exposure time. The
University of South Africa (2026) also stipulates that the lab coat must be regularly
washed and repaired, ensuring it maintains its protective integrity — a standard not
applied to ordinary clothing worn into the laboratory.
Baird, C. and Cann, M. (2012) further emphasise that personal protective equipment,
including the lab coat, forms the last line of defence against chemical exposure and
must meet specific standards that everyday clothing simply cannot fulfil. Therefore, a
student's argument that ordinary clothing is a sufficient substitute fundamentally
misunderstands the purpose and design requirements of proper PPE.
2. Exclamation Mark, Flammable, and Corrosive symbols (6 marks)
Safety symbols on chemical containers provide critical hazard information that must be
understood before handling any reagent (Occupational Health and Safety Act 85 of
1993).
• Exclamation Mark (Harmful/Irritant): According to the University of South
Africa (2026), this symbol indicates substances that may cause damage to
health, including irritation to the skin, eyes, and respiratory organs. These
chemicals cause slight damage when taken into the body. The University of
South Africa (2026) advises that contact with the human body must be avoided
entirely, including inhalation of vapours, and medical advice should be sought if
illness occurs.
• Flammable: The University of South Africa (2026) defines this symbol as a
warning that the chemical has an extremely low flash point and boiling point,
meaning it can ignite easily upon contact with a source of ignition, or may catch
fire when exposed to air. Some flammable substances also evolve highly
UNISA
2026
All questions are answered and verified align with marks allocations
, QUESTION 1
1. Why normal clothes are insufficient as a substitute for a lab coat
Normal everyday clothing does not provide adequate protection in a chemical
laboratory. According to the University of South Africa (2026), a lab coat must be knee-
length, made of cotton, and kept fully buttoned with sleeves unrolled at all times during
laboratory work. This design creates a protective barrier specifically engineered to resist
chemical splashes and spills that would otherwise penetrate ordinary fabric and
contact the skin directly.
Ordinary clothing, particularly synthetic fabrics, presents additional dangers. As noted
by the University of South Africa (2026), synthetic materials may melt or ignite when
exposed to heat or open flame, whereas a cotton lab coat offers greater thermal
resistance. Furthermore, street clothing cannot be removed rapidly in an emergency,
whereas a lab coat can be quickly discarded to minimise chemical exposure time. The
University of South Africa (2026) also stipulates that the lab coat must be regularly
washed and repaired, ensuring it maintains its protective integrity — a standard not
applied to ordinary clothing worn into the laboratory.
Baird, C. and Cann, M. (2012) further emphasise that personal protective equipment,
including the lab coat, forms the last line of defence against chemical exposure and
must meet specific standards that everyday clothing simply cannot fulfil. Therefore, a
student's argument that ordinary clothing is a sufficient substitute fundamentally
misunderstands the purpose and design requirements of proper PPE.
2. Exclamation Mark, Flammable, and Corrosive symbols (6 marks)
Safety symbols on chemical containers provide critical hazard information that must be
understood before handling any reagent (Occupational Health and Safety Act 85 of
1993).
• Exclamation Mark (Harmful/Irritant): According to the University of South
Africa (2026), this symbol indicates substances that may cause damage to
health, including irritation to the skin, eyes, and respiratory organs. These
chemicals cause slight damage when taken into the body. The University of
South Africa (2026) advises that contact with the human body must be avoided
entirely, including inhalation of vapours, and medical advice should be sought if
illness occurs.
• Flammable: The University of South Africa (2026) defines this symbol as a
warning that the chemical has an extremely low flash point and boiling point,
meaning it can ignite easily upon contact with a source of ignition, or may catch
fire when exposed to air. Some flammable substances also evolve highly
