I nearly got busted on 0.05%, even though I am careful. I just wasn't thinking well that day!!

The Eltham Wine Guild encourages the responsible consumption of Alcohol.

This appears near the top of each Guild news letter. Adding this to the news letter was prompted by a Guild meeting attended by the police, who demonstrated to us the issues of responsible drinking, and gave out to each person there a Party Safe Drink Drive Guide. See photos below

The consequences of going Over The Limit are of course considerable. Not only do you increase the risk to yourself, your passengers, and the public, but you risk a fine; de-merit points, or even loss of your drivers licence for a time.

Also, with most car insurances, if you have an accident while driving over 0.05, your insurance is totally void, regardless of whose fault the accident was otherwise. Wow!!

So how did I get it wrong? Easy. I drank to my usual pattern as for a 4-00pm commencement for a theatre matinee in the city, but forgot to factor in the fact that I had my lunch, with wine about 1 3/4 hours later than usual, thus reducing the time from my first drink till the time I was breathalized by nearly 2 hours from my normal practice. That two hours would have reduced my blood alcohol content by, (BAC) by nearly 0.030%, (that is by 0.015% plus or minus for each standard drink or hour elapsed.)

Here is what happened on that day

1. 250ml red wine, (12% Al)

- at 2-30pm to 2-45pm, (normally I would start lunch at about


- with a large, well filled sandwich.

2. 230 ml white wine, (13%Al)

- at 5-00 to 5-15pm (theatre intermission)

- nothing to eat.

3. 150 ml red wine (say 13%)

- at 7-30 to 7-50pm.,

- after a bowl of soup, and with a seniors meal; Lambs fry, bacon

and veggies. No other drinks after finishing red wine.

4. Breathalized at 8-15pm. Borderline, according to the testing police, but eventually the machine "beeped" and I was sent on my way.

That's the story.

IF you are interested to see how I analyzed the situation later, using the Party Safe Drink Drive Guide, then please read on.

REMEMBER, that this guide is only approximate.

Staying Under 0.05 Calculator
Staying Under 0.05 Instructions

1. I used The Party Safe Drink Drive Guide given to us at the Responsible Drinking Guild program a year or so ago.
2. Basic standard drink of wine. 100mls at 11% alcohol.
3. Topping up. Add or subtract 0.015% for each standard drink consumed or hour lapsed.
4. My body weight at the time = 78kgs.
5. Many factors affect the blood alcohol content, (BAC). These include whether you are male or female; how much alcohol you drink over what time period; how long since you have eaten; fitness; your mood; medication.

My reconstruction of that drinking, using the party safe guide.
Drink, 2-30 to 2-45pm. 250 mls red (@ 12% Al)
Standard drink is 100 mls at 11%
So 250 mls at 12% = 250 X 1.1 (0.1 is the difference between 11% standard, and 12% actual) = 2.75 Standard drinks; finished at 2-45pm.

@ 3-45pm (After 1 hour), level = 0.052 according to party guide

@ 4-45pm (After 2 hours, level = 0.037 according to party guide (+/- 0.015)

@ 5-00pm (another ¼ hours = 0.033 (subtract ¼ of 0.015 = - 0.004 from 0.037)

Note. Although the above figures are as for BAC after 1 hour, drinking on an empty stomach, and in fact I had had a good sandwich, for the purpose of this exercise I have counted the above as for on an empty stomach, because although food slows up the alcohol absorption, it seems to me that all of that alcohol would have been absorbed by the time I was breathalized.

Drink, 5-00pm to 5-15pm 230 mls white (@ 13% Al)

Standard drink is 100 mls at 11%

So 230 mls at 13% = 230 X 1.2 (0.2 is the difference between 11% standard
and 13% actual)

= 2.75 standard drinks finished at 5-15pm

@ 6-15, we now have 2 components

1. Residual of the initial red wine as at 5- 00pm,
reduced by 1 ¼ hrs since 5-00pm
= 0,033 – (0.015 X 1 ¼ hours from 5pm to 6-15pm)
= 0.033 – 0.0187 (say 0.088)
= 0.014

2. BAC from 230 mls of white wine, finished at 5-15pm,

@ 6-15pm (after 1 hour) = 0.052

Total at 6-15 = 0.066

@ 7-15pm (after 1 hour) (0.066 – 0.015 = 0.051

@ 8-15pm (after 1 hour) when breathalized = 0.051 - 0.015 = 0.036 BAC.

But to that has to be added the effect of the 150ml of red wine from 7-30 to 7-50pm. Call it 13%.

150 ml X 1.2 = 180 = 1.8 standard drinks.

From the Safe party chart, 1.8 standard drinks, on an empty stomach = 0.032.

But I had this drink with a good meal, after a bowl of soup, and 10 minutes wait for the main meal before I started drinking.

The mid point of that drink was 7-40pm, 35 minutes before I was breathalized. So the BAC effect would not have been more than ¼ of 0.015 (standard 1 hour unit +/- = 0.004.

Add 0.004 to 0.036 as at @8-15pm = 0.040

So it seems to me I could have been getting close to 0.05%.

So, for a final focus: -

1. I had thought that the small thermos that I took the theatre with white wine in was only 180mls, while it was in fact 230mls. Mistake 1.

2. While this drinking pattern had not been a problem to me in the past, the total period from first drink till breathalized was two hours shorter than normal, because I had my lunch nearly two hours later than normal that day, due to other arrangements. I had not factored that compression of normal drinking time, Mistake 2, into my keeping track of my 0.05%, which I try to do all the time

3. If you have an accident in the car while over 0.05% then under most car insurances your insurance is void regardless of fault otherwise. It's a sobering thought; pardon the pun!!!
One consequence of many.

4. This also shows that it can be pretty complicated to keep track of 0.05% using a simple ready-reckoner guide, like the party Safe Drink Drive Guide