Indoor Air Quality

Measurement in Hong Kong

Speaker : Prof. YEUNG Lam Lung The Hong Kong University of Science and Technology

• The seminar builds on knowledge learnt in the DSE curriculum

– Chemistry: Topics IV, XI, XIV and XV – Combined Science (Chemistry): Topic IV

Curriculum Links

• For offices and public places • Voluntary for certification

• Certificate valid for 5 years

• Two Level ‘Excellent’ class or

‘Good’ class

Indoor Air Quality (IAQ) Certification Scheme

• Physical parameters: temperature humidity air movement • Excellent Class : 20-25.5oC • Good Class : < 25.5oC

12 IAQ Parameters

• Formaldehyde • Volatile Organic Compounds (VOCs) • Carbon dioxide • Carbon monoxide • Nitrogen dioxide • Ozone • Radon • Respirable suspended particles (PM10)

Chemical parameters

• A kind of VOCs • Released from pressed wood

products, carpet adhesives or burning cigarettes

• Tested with DNPH (2,4-dinitrophenylhydrazine) obtaining a coloured product

Formaldehyde (HCHO)

HCHO +

• Ozone is produced by photocopiers, laser printers

• Such equipments utilise UV light or high voltage and cause ionisation of oxygen

Ozone (O3)

O2 + h 2O + 2O2 2O3

• Radon is a noble gas. • Isotope (Rn-222) is formed from radium

(Ra-226) which is found in soils and rocks, particularly granite.

• Rn-222 is radioactive. • Rn-222 decays to gives toxic substances.

Radon (Rn)

226Ra222Rn218Po214Bi210Pb

Rn

Rn

For details of the Indoor Air Quality

Measurement, please refer to the seminar.

Glossary

Indoor air quality 室內空氣質素

2,4-dinitrophenylhydrazine 2,4-二硝基苯肼

volatile organic compounds 揮發性有機物

radon 氡

respirable suspended particles 可吸入懸浮粒子

granite 花崗岩

• The link to EDB Glossary (Chinese/English) is http://www.edb.gov.hk/tc/curriculum-development/kla/science-edu/ref-and-resources/glossary.html

EDB Glossary