Microbiological tests of the stability of use-solutions of the

instrument disinfectant TPH-5314 (GIGASEPT FF)

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When instrument disinfectants are used, the prepared solution is often used for several
days. To what degree the solution remains effective over such a period must therefore be
tested. Such tests have been carried out for the instrument disinfectant TPH-5314.

In the tests of effectiveness of chemical disinfectants in accordance with the requirements
of the DGHM for the new VIIth List, a test of the stability of the solution over 24 hours is
required (Test and Evaluation of Chemical Disinfection Processes - Requirements for
inclusion in the VIIth List, as of 1 February 1984): Hygiene + Medizin 9, 41 - 46 (1984).
The method used is the quantitative suspension test, and the two test microorganisms
Staphylococcus aureus and Pseudomonas aeruginosa. The effectiveness is checked after
a 24-hour standing time at 37

°C, with 0.2 % bovine albumin being added to the

disinfectant soltuion at the beginning of the standing time.

In the test reported here, the effectiveness of the disinfectant solution was tested in
accordance with the method described above over a period of sixteen days. The tests
were carried out on the 2, 3 and 5 % solutions. These solutions were kept in a 600 ml
glass beaker (500 - 500 ml capacity), with appropriate amounts being removed for testing
at the relevant times. The glass beakers were loosely covered with aluminium foil.

The test results are presented in Table 1 and Table 2. The results obtained with the 5 %
solution are not given in the tables. It can be seen that no reduction in the effect of the
concentrations studied was detectable during the entire standing time. With both
Staphylococcus aureus and Pseudomonas aeruginosa, uniform effectiveness was able to
be proved over the entire period.

- 2 -

Overall

evaluation

The 2, 3 and 5 % solutions of the instrument disinfectant TPH-5314 were tested in the
quantitative suspension test over a standing time of sixteen days. During the standing
time, a protein load of 0.2 % albumin was added to the solutions. The solutions stood at

room temperature or at 37

°C. The test organisms used were Staphylococcus aureus and

Pseudomonas aeruginosa. The test results show that there is no reduction in effect over
the period studied.

Norderstedt

24 September 1985

FO-Bio/Dr.Eig/kr

Dr. U. Eigener

GIG2801.S16/ah

Table 1

Standing time tests with the instrument disinfectant TPH-5314

(quantitative suspension tests)

(Load during the standing time: 0.2 % albumin)

Test bacterium

: Staph. aureus (initial counts: 3.9

⋅10

8

- 1.3

⋅10

9

/ml)

Logarithmic reduction factor

Contact time

(minutes)

Conc

.

(%)

Initial

value

1 day

2 days

4 days

7 days

9 days

11 days

14 days

16 days

5

2
3

2.06
3.12

2.28

≥ 4.60

2.77

≥ 4.70

2.95

≥ 4.48

4.40

≥ 4.70

2.71

≥ 4.46

4.48

≥ 4.84

3.87

≥ 5.00

5.36

≥ 5.84

30

2
3

> 4.30
> 4.30

RT

≥ 5.04

≥ 5.04

≥ 4.90

≥ 4.09

≥ 4.48

≥ 4.48

≥ 5.11

≥ 5.11

≥ 4.57

≥ 4.57

≥ 4.78

≥ 4.78

≥ 5.18

≥ 5.18

≥ 4.95

≥ 4.95

60

2
3

> 4.48
> 4.48

≥ 5.04

≥ 5.04

≥ 4.95

≥ 4.95

≥ 4.48

≥ 4.48

≥ 4.70

≥ 4.70

≥ 4.56

≥ 4.56

≥ 4.78

≥ 4.78

≥ 4.70

≥ 4.70

≥ 5.28

≥ 5.28

5

2
3

4.30

≥ 4.60

≥ 4.70

≥ 4.70

≥ 4.48

≥ 4.48

≥ 4.70

≥ 4.70

≥ 4.46

≥ 4.46

≥ 4.84

≥ 4.84

≥ 5.00

≥ 5.00

≥ 5.84

≥ 5.84

30

2
3

37

°C

4.34

≥ 5.04

≥ 4.90

≥ 4.90

≥ 4.48

≥ 4.48

≥ 5.11

≥ 5.11

≥ 4.57

≥ 4.57

≥ 4.78

≥ 4.78

≥ 5.18

≥ 5.18

≥ 4.95

≥ 4.95

60

2
3

≥ 5.04

≥ 5.04

≥ 4.95

≥ 4.95

≥ 4.48

≥ 4.48

≥ 4.70

≥ 4.70

≥ 4.56

≥ 4.56

≥ 4.78

≥ 4.78

≥ 4.70

≥ 4.70

≥ 5.28

≥ 5.28

RT: room temperature (22

°C ± 2°C)