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Chemically, this poison is similar to '1080', but unlike the latter which is an extremely fine
powder, is in crystal form, which increases the safety factor in dispensing. It is readily soluble
in water, odourless and said to be tasteless.
The median lethal dose (LD50) for Common rat is about 15 MG/KG of body weight as against
1 MG/KG for'1080' and is therefore about 15 times less lethal to rats. After a lethal dose the
speed of onset of warning symptoms is said to be slower than Zinc Phosphide for which the LD50
is 40 MG/KG.
It was considered desirable to obtain by over all test baiting a basis on which the effectiveness
of '1081' could be assessed after four "direct" controls, and this was carried out during
the period 10th - 13th September, 1956, three months after the final '1080' control, and repeated
the 19th - 22nd November, 1956, ten weeks later, being three weeks prior to the institution of the
first '1081' control.
For the first test, 402 sewer entrances were baited and the baits, each 4 ozs of damp sausage
rusk, were left down for three days, and on examination 103 "takes" (84 complete, 6x¼, 8x½
and 5x¼) were recorded. The weather, an important factor in sewer control, was favourable, and
the 299 test baits recorded as negative were in good condition after three days.
For the purpose of the second overall test ten weeks later, 403 entrances were baited, and
on examination 174 "takes" (165 complete and 9x¼) were recorded. The weather was again
favourable, the sewer entrances being dry and the conditions ideal for the test.
The significant feature of the test baiting results was the formidable increase in the number
and the quality of the takes, indicating the rapid build-up and distribution in the intervening
period of nearly six months from the final '1080' control.
These results did provide a sound basis on which to judge, and the first '1081' control of
such a nature to be applied in this country was carried out in December, 1956, two weeks after
the second test, the procedure being similar to the '1080' control, in dispensing and distribution.
A total of 394 sewer entrances were treated, each bait being 4 ozs comprising sausage rusk
and water at equal parts by weight, evenly mixed with '1081' at a concentration of 1%. The
baits were left down from 3-4 days before clearance and on examination 87 "takes" (8 complete,
7 x 39 x Yt and 33 x *4) were recorded. K total of 57 bodies were recovered, and no doubt a
number were washed away in fast flows, as during the course of the work heavy and prolonged
rain was experienced on several occasions. The majority of the bodies were found in shallow
flows a considerable distance from the baits.
The second treatment was applied in March, 1957, when 401 entrances were baited, and the
recorded result on examination was 60 "takes" (11 complete, 7x¼, 18x½ and 24x¼ or less).
In this instance 39 bodies were found in shallow and slow streams. The procedure for this and
subsequent controls was altered to allow the baits to remain down longer, the timing to include a
week-end when the discharge of waste from the many catering premises into the sewers from
Friday night to Monday morning is at its minimum.
The third treatment applied in May - June embraced 396 entrances, and the baits were down
4-5 days. The recorded result was 18 "takes" (4 complete, 4x¼, 8x½ and 2x¼) and 4
bodies were found. The weather prior to, and including the treatment was good, and the baits
when cleared were in good condition.
The fourth and final control of the series was carried out in September, when 398 entrances
were baited. The recorded result on examination was 17 "takes" (4x¼ and 13x½) and 10
bodies were found making a total of 110 for the series.
On completion of the '1081' series, it was again considered desirable to obtain by overall
test baiting similar information to that supplied by the tests carried out on completion of the
Sodium Fluoroacetate '1080' direct controls, June, 1956, and preceding the institution of the
'1081' series.
Three tests were applied on the 10th October, 1957, 5th December, 1957, and the 6th March,
1958, thus covering a period of six months from the final '1081' control, September, 1957.
For the first overall test three weeks after the poison control, 400 entrances were each
baited with 4 ozs of soaked wheat and the baits were left down 5 days. On examination 27
"takes" (15 complete, 9x¼ 1x ½ and 2x¼) were recorded.
This was followed by the second test 8 weeks later when 406 entrances were baited, each
bait being 4 ozs of damp sausage rusk. The recorded result in this instance was 69 "takes"
(58 complete, 3x¼ and 8 x½).
For the final test 13 weeks later, and 6 months after completion of the '1081' series of
poison controls, 394 entrances were baited, and the baits, each 4 ozs of soaked wheat, were left
down 7 days. The recorded result was 194 complete "takes". In this instance, bad weather was
experienced. There was heavy rain on the 2nd day when baiting was completed, and this was
16.