The effect of a “one for the road” drink of hard liquor, beer or wine on peak breath alcohol concentration in a social drinking environment with food consumption

M a rtin H . B r e e n , M .S ., Q u i T . D a n g , M .S ., J o se p h T . J a in g , B .S .,

G reta N . B o y d ,

O range C ounty Sheriff-C oroner’s D epartm ent, C alifornia

F orensic Science Services

IN T R O D U C T IO N

E ven though it is a traffic violation to drive a m otor vehicle w ith a b lood alcohol concentration

(BAC) o f 0 .08% o r higher; there are over 20 ,000 individuals w ho are arrested every year fo r

this violation in O range C ounty , C alifornia . T he m ajority o f these d rivers consum e different

types o f alcoholic beverages including hard liquor, beer, and w ine from a bar o r a party over a

period o f a few hours and w ith d inner o r a snack.

Expert w itnesses testify ing in driving under the influence o f alcohol cases are often asked in

court to back-extrapolate the d riv er’s B A C at the time o f the traffic stop by using the know n

result o f a blood, breath o r urine test adm inistered one o r tw o hours after the incident. Since

B A C is a function o f tim e, the d river’s B A C at the tim e o f driv ing could be low er than the BAC

at the time o f the chem ical test. This rising B A C (Jones, 1990) is often seen in drivers w ho

have a “one fo r the road” d rink ju s t before they are pulled over by a police officer on the

suspicion o f driv ing under the influence o f alcohol. In o rder to p roperly calculate the d riv er’s

B A C at the time o f driv ing (M .J. L ew is, 1986; K .O . L ew is 1987; D ubow ski, 1985; Jo n e s,

1988), detailed inform ation such as the d riv er’s d rinking pattern , the type o f alcoholic beverage

consum ed , and the presence o r absence o f food in the d riv er’s stom ach (Jones, 1991; H olt,

1981; R ose, 1979; W ilk inson , 1977) m ust be taken into consideration . A lthough there are

studies reporting that the m ajority o f alcohol is absorbed quickly (G ullberg, 1982) even w hen it

is consum ed together w ith a large m eal (Jones and N eri, 1991), no p rev ious study has reported

the absorption and distribution o f the “one fo r the road” drink.

The purpose o f this series o f studies is to exam ine the m axim um increase in breath alcohol

concentration and the tim e it takes to reach the peak after finishing the “one fo r the road” d rink .

T he sam e indiv iduals consum ed hard liquor, beer o r w ine on three separate occasions in a social

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environment with food.

M E T H O D

S u b je c ts an d c o n d itio n s

Thirteen healthy volunteers, seven m en and six w om en, participated in these studies and were

designated as subjects A through M . T hey described them selves as social d rinkers w ho

consum e alcohol only occasionally . The mean age o f the m ale and fem ale participants w as 32

and 28 years old respectively. The m ean body w eight o f the m ale and fem ale participants w as

164 and 134 pounds respectively. The subjects consum ed hard liquor fo r the first study , beer

fo r the second study and w ine fo r the third study. N ine o f thirteen subjects participated in all

three studies, w hile the rem aining subjects w ere able to participate in at least one o r m ore o f the

studies. A t the beginning o f each study, the d rinking subjects w ere requ ired to perform a breath

test show ing that they w ere alcohol free.

All subjects ate d inners w hich included com m on food such as ho t dogs, ham burgers,

sandw iches, burritos, m eatballs, rice, pasta, soup, salad, fruits and/or vegetables, immediately

before o r shortly before drinking started. Snacks w ere available throughout the study. The

subjects w ere instructed to keep the same activities fo r Day 1 and D ay 2 o f each study. A t the

com pletion o f the study, the subjects w ere driven hom e by designated drivers.

F o r each study, m onitors w ere assigned to each subject to record relevant inform ation such as

the subjects’ activities during that day, the kind o f food they had fo r d inner, the time they had

dinner, their age, sex and w eight. The m onitors also recorded the am ount o f d rinks consum ed ,

the tim e it took to consum e the d rinks, the time o f the breath tests and the duplicate breath test

results. E ach subject was assigned to the sam e breath alcohol instrum ent in D ay 1 and D ay 2 o f

each study.

E ach study consisted o f tw o consecutive days. D ay 1 served as a control in w hich the subjects

consum ed a know n am ount o f alcohol at their ow n rate until their B rA C w as near the 0 .08%

level. C hips, d ip , and o ther snacks w ere available; and the subjects talked, played cards, poo l,

etc... w ith m usic in the background. T he atm osphere w as sim ilar to that o f a bar o r a party . The

subjects’ duplicate breath sam ples w ere taken fifteen m inute after finishing each drink. A fter the

last drink, the sub jects’ B rA C s w ere m easured at 15-20 m inute intervals fo r approxim ately four

hours to establish their tim e to peak and their elim ination rates during the post-absorptive phase.

D ay 2 w as a repeat o f D ay 1 w ith the addition o f the “one fo r the road” d rink .. The subjects

w ere given a “one fo r the road” d rink w hen their B rA C started to decline. T he am ount o f

alcohol for this drink was 30 to 60 m illiliters o f hard liquor fo r the first study , 355 m illiliters o f

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beer fo r the second study and 177 m illiliters o f w ine fo r the third study. The sub jec ts’ B rA C s

w ere also recorded every 15-20 m inutes after the final drink until the com pletion o f the study ,

approxim ately tw o hours later.

The m ain purpose o f D ay 1 w as to obtain a baseline curve fo r each subject that could later be

com pared w ith the B rA C curve o f D ay 2. It was to ascertain that the B rA C increase o f the “one

fo r the road” drink in D ay 2 w as attributed to this drink and w as not affected by o ther biological

factors. It also helped to determ ine the dosage, the consum ption rate fo r each subject in D ay 2;

and to determ ine w hether o r no t a subject could handle an alcoholic beverage o ther than his/her

preference, so he/she could continue to D ay 2.

In s tr u m e n ta tio n

In toxilyzer 5000 instrum ents, m anufactured by CM I Inc., w ere used to m easure the sub jec ts’

B rA C . These instrum ents have been in use in all O range C ounty law enforcem ent agencies

since 1987. B reath tests w ere taken in duplicate and the results m ust agree within 0 .020% . If

the tw o resu lts did no t agree, a th ird test w as taken. C alibration checks w ere perform ed on each

instrum ent before, during and after its use each evening. They w ere w ithin 0 .010% o f the

know n values o f the sim ulator solution. A ir b lanks betw een sam ples gave a read ing o f 0 .000% .

A lc o h o lic b e v e r a g e s

F or hard liquor, subjects consum ed S m irnoff V odka , R onrico R um , tequila, o r W illiam s

B ourbon W hiskey . F o r beer, they consum ed M iller G enuine D raft , C orona or B ud w eise r .

F o r w ine, they consum ed M ondavi R iesling , B eringer W hite Z infandel , M ondavi Fumetf

B lanc , R u therford C abernet , C olum bia C rest M erlo t , o r chardonnay.

C a lc u la t io n s

BrA Cs w ere plotted against time to obtain the B rA C curve fo r each subject. Each data point

represents the average o f the duplicate BrACs.

D ata collected from D ay 1 o f each study w ere used to calculate the tim e to peak after the last

drink and the elim ination rate o f each subject.

D ata collected from D ay 2 in each study w ere used to calculate the time to peak and the BrA C

change after fin ish ing the “one fo r the road” drink.

Because o f a 15 m inute w aiting period for the dissipation o f m outh alcohol, the change in BrA C

after the last drink is the difference betw een the highest B rA C and the last m easurem ent before

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the last drink. Plateaus w ere observed fo r subjects w hose B rA C s rem ained w ithin 0 .010% o f

the highest B rA C ov er time w ith the beginning o f the plateau being the first data poin t w ithin

0 .010% from the h ighest m easurem ent.

R E S U L T S

S h a p es o f B rA C cu rves:

The shape o f the B rA C -tim e profile fo r m ost individuals follow ed the expected course o f a rapid

rise during absorp tion , a clear peak, and a steady fall during elim ination. A typical profile is

observed in F igure 1. The second peak representing the B rA C rise after fin ish ing the “one fo r

the road” drink is also seen in this figure. P lateau , w hich is the part o f the B rA C curve within

0.010% from the highest poin t w ithout a steady decline in B rA C over tim e is also observed and

seem s to occur m ore o ften w ith hard liquor o r w ine and is not seen in beer drinkers.

B rA C rise an d tim e to peak a fter fin ish in g th e “on e for th e r o a d ” drink:

Eleven subjects w ho had 30 to 60 m illiliters o f hard liquor gave an average B rA C rise o f

0 .017% from the last m easurem ent w ith a range o f 0.005 to 0 .034% . T he average time to peak

or plateau after this “one fo r the road” drink w as 18 m inutes w ith a range o f 0 to 35 m inutes.

T he average rise o f B rA C from 9 subjects w ho drank 355 m illiliters o f beer w as 0 .016% from

the last m easurem ent w ith a range o f 0.008 to 0.028% . The average tim e to peak or p lateau after

this “one fo r the road” beer d rink w as 16 m inutes w ith a range o f 15 to 20 m inutes. T his is

com parable to an average rise o f 0 .016% (range o f 0 .007 to 0 .026% ) from the last

m easurem ent in a 20 m inute average tim e (range o f 15 to 45 m in.) to peak again fo r 10 subjects

w ho had 177 m illiliters o f w ine “for the road.”

T im e to peak or p lateau a fter f in ish in g th e last drink:

T im e to peak or to the first point o f the plateau o f the last drink (not the “one fo r the ro ad ”) does

not d iffer significantly fo r hard liquor, beer o r w ine. The average tim e is 15 m inutes fo r hard

liquor, 19 to 22 m inutes for beer and 23 to 24 minutes- fo r w ine. The time to peak is

reproducib le w ithin 5 m inutes fo r 9 o f 11 hard liquor drinkers, fo r 5 o f 10 beer drinkers and fo r

4 o f 10 w ine drinkers. T he range o f time to peak o r plateau fo r the last d rink in this study is

from 0 to 35 min. fo r hard liquor, 15 to 40 m in. fo r beer and 5 to 60 m in . fo r w ine.

The tim e to peak o r plateau o f the “one for the ro ad ” drink is very close to that o f the last

drink.

B rA C ch a n g e a fter fin ish in g th e last drink:

The average B rA C rise from the m easurem ent before the last d rink to the peak or p lateau is from

0 .022% to 0.028% for all three types o f alcoholic beverages. T hese values are h igher than those

o f the “one for the road” d rink (0.016% to 0.017% ) because the last d rink w as consum ed while

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subjects w ere still in the absorptive phase o f the B rA C curve and the “one fo r the road” drink

w as consum ed in the elim ination phase.

F ig u re 1 : T y p ica l B rA C cu rv e o f “o n e for th e roa d ” stu d y (su b je ct A , w in e).

Time (min)

D otted lines (day 1), last d rink at 70 min.

S olid lines (day 2), last d rink at 85 m in ., “one fo r the road” d rink at 180 m in

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