A BOWED head, a quick snip and teenagers at Hong Kong International School can breathe easy again - as long as they have been drug-free for at least three months.
The students are taking part in Hong Kong's first in-school random drug tests, which began on Wednesday.
A computer programme selects two high school students each day for hair testing, deemed to be less intrusive and more reliable than the previous urine tests.
'It's been going fine. We got them all ready by having assemblies where we show how it's done on administrators,' said school spokesman Miltinnie Yih.
'It's an inch across, but just one row of hair. We don't take it from the hairline, we take it from the nape of the neck.' Previously, only students suspected of taking drugs were asked to undergo tests.
The new system - which reveals opiates, barbituates, cannabis and amphetamines taken within the last three months - will test two people daily, with samples sent to America for analysis at the end of each week.