Early Shift After Beer and a Sedating Antihistamine
It is 07:10. You are due to drive a 5.5-tonne LGV from Kwun Tong to Tsuen Wan with a chilled-food delivery before 08:30. You finished work at 23:00 yesterday, drank three 330 ml bottles of 5 per cent beer between 01:00 and 02:00, and slept from 02:30 to 06:30. You have a head cold and took a 4 mg chlorpheniramine tablet at 06:00; the packet warns it may cause drowsiness. You feel a bit fuzzy but not drunk. Your vehicle's load is 1,200 kg, within the 1,500 kg payload. The route includes Kwun Tong Bypass and Tsuen Wan Road. Your employer has sent two text messages asking for an ETA. A colleague says he can cover the delivery if you are not fit.
1. Assess your fitness to drive at 07:10 and explain the factors you are weighing.
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Do not drive. Three 330 ml bottles of 5 per cent beer contain roughly 39 g of alcohol, and although some will have been metabolised by 07:10, you cannot assume your reading is below the Hong Kong limit of 50 mg per 100 ml of blood, 22 micrograms per 100 ml of breath or 67 mg per 100 ml of urine. Four hours of sleep after drinking, a head cold and a 4 mg chlorpheniramine tablet all add up. Chlorpheniramine is a sedating antihistamine; it slows reaction time and causes drowsiness, and alcohol plus a sedative is worse than either alone. Feeling a bit fuzzy is itself a warning. The chilled-food deadline does not justify the risk.
2. What are the legal and safety consequences of driving in this condition?
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The legal position is separate from the safety position. Driving with a blood alcohol concentration above the prescribed limit is an offence in Hong Kong, and you can also be convicted for driving while unfit through drink or drugs even below the limit. A conviction can bring a fine, imprisonment, disqualification and demerit points, and your employer's insurer may refuse cover. If you have an accident, the consequences are far worse. The safe and lawful decision is not to move the vehicle.
3. What should you do about the delivery and the messages from your employer?
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Tell your employer now that you are not fit to drive and accept the colleague's offer to cover the delivery. If you are already at the depot, leave the vehicle parked and hand over the keys. Do not use caffeine, a cold shower or fresh air as a substitute for sobriety or sleep. Go home, sleep, and do not drive until the alcohol has cleared and the medication effect has worn off; if the cold or medication still makes you drowsy, see a doctor or pharmacist about a non-sedating alternative before your next shift.