He has been in the hardware store business for 25 years, and in that time, he has seen them all.
Even though there are now fewer youngsters who buy glue and thinner to inhale and get their illegal high, Ah Teck still sees them occasionally at the Tampines shop he works in.
"They'll look blur, and you can tell they are buying the substance for their own pleasure," said the employee at Chin Hoe Hup Kee Hardware in Mandarin.
"I won't sell to these people as well as youngsters under the age of 18."
The Central Narcotics Bureau (CNB) said that anyone convicted of selling or offering to sell intoxicating substances to a suspected abuser can be jailed up to two years and fined $5,000.
The New Paper spoke to 20 hardware stores on Wednesday and found out only four of them sold items like glue and paint thinner.
And all four said they are aware of this rule.
Like Ah Teck, the three other shopkeepers also said they refuse to sell such substances to youngsters as an extra precaution.
Ms Angeline Lim, another shopkeeper, said: "If these youngsters still insist on buying, I will tell them to ask an adult or a parent to buy the items instead."
Ms Lim, who owns B88 Hardware and Paint Supplies at Dawson Road, near Alexandra Road, added that after being in the business for seven years, she can easily identify inhalant abusers.
"They look 'high' and I will immediately say no to them."
Vigilant shopkeepers like Ah Teck and Ms Lim have been extra diligent in helping curb the inhalant abuse problem in Singapore.
And it appears their efforts have paid off.
The number of arrests for inhalant abuse has gone down from 499 in 2010 to 60 in the first half of this year.
In another move to tackle the problem, the CNB said that since 2010, it has been using the "cluster approach" when dealing with shopkeepers who sell products like glue and paint thinner.
Its spokesman said: "When a particular shop is found to be selling inhalant products to abusers, both that shop as well as other similar shops in the vicinity will be alerted to exercise more caution in selling (them)."
The CNB added that the shopkeepers will be given documents known as "letters of advice" and "letters of notice". (See report at right.)
And the number of such documents handed out dropped last year.
Eighteen letters of advice were issued last year compared to 167 in 2010.
The number of letters of notice issued went down from seven in 2010 to four last year.
The CNB spokesman said: "Often, shops that are issued (with the letters) may completely cease selling (such) products."
This could mean there are now fewer shops selling paint thinner and glue.
CNB also said it "will continue to work closely with shopkeepers by providing posters and other anti-inhalant publicity materials" to them.
These will serve as reminders on the harmful effects of inhalant abuse.
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