I am perturbed that harmful phthalates are found in many fragrances, given that malls, hotels and even buses are using scented air to enhance customer experience (Are scents for buses and buildings safe?, by Ms Liu I-Chun; May 1).

In 2010, phthalates found in toys were the cause of mass vomiting and diarrhoea in a local primary school (Toy to blame for bout of vomiting in school; March 5, 2010).

Are there phthalate-free options? How are chemicals in fragrances regulated?

The worst would be using fragrances to mask odours and uncleanness, such as dirty toilets and mildew.

In the case of Tower Transit, I believe most commuters would rather it focus on its core proposition of bus reliability and customer service, rather than on scented buses (No. 97: A new fragrance on wheels; ST Online, Feb 28).

The National Environment Agency should make a sound and informed stand on the use of scented air.

Lim Teck Koon