OFFICE MEMORANDUM ° STANFORD UNIVERSITY

Date: July 8, 1959

VV aA

To : Self

From . ne gee
RE Aa SPR

SUBJECT:

Session today in Biophysics conference foom on decontamination

tactics for space vehicles.

Present were:
Dunlap, from the Department of General Engineering, General Electric
Corporation, Schenectady, New York
Bauman,
Davies, from JPL
Derbyshire, from NAS
Phillips, from Fort Detrick

and mysel f

I. Quartermaster Corps has planned for large radiation facility at Stockton;
G. E. can do this at Vallecitos.

2. Back contamination problem should eventually be referred to WHO.

5. Classification of contamination into (a) pollution. (b) infection.

Pollution can be either viable or sterilized. Pollution not
serious if highly localized. Bauman seemed to think that most
impacts would be localized.

4, Considerable discussion about handling for cleanliness; Bauman was
not too sure how this might be done for internal parts although,
of course, the polished surfaces are very carefully wiped. He did
not know the nature of the resin used potting compound. Replicate
copies are kept of various missiles although not a great deal of
caution is taken to see that they are exact replicas with identical
lot numbers on various equipment.

DS Detrick had not been very successful in finding residual self-sterilizing
oils although obviously solutions of ethylene oxide in oils would be
momentarily disinfectant. | did not get the impression that they have
done very much investigation of the epoxides Of higher molecular

weight.
Page 2.
OFFICE MEMORANDUM ° STANFORD UNIVERSITY

Date:
To
From: CEDERSCRG -— Gre tics
SuBJECT: Decontamination Meeting

We do not know how to evaluate the possibility that high vacuum

by itself may be lethal owing to the distillation of fats. There
is little information on the extreme vacuums that have been tested
and certainly nothing that compares to availability in space. More
pressure should be put on this for a satellite experiment. Most

of the discussion did center on the properties of ethylene oxide
and it was perfectly obvious that this would be the agent of choice.
This has a high degeee of reactivity and penetration and when used
as a 10 per cent gas ina diluent tike CO., or freon is quite

safe from the point of view of inflammability. However. under
these conditions, drastic sterilization may take something like

10 hours at one atmosphere pressure. Fhillips quoted a figure

of 2,000 milligram hours per liter as a reasonable dose level

for ''complete'' sterilization. He felt that any consideration

of manned vehicles should also include the problems of microbe
barriers both for the investigation of the planet and for the
return of the vehicle. He also demonstrated the type of equipment
in which sterilization is possible for example, a freon-ethylene-
oxide-aerosol bomb which can be pierced and opened inside of a
large polyethylene bag. He seems to feel that the elaborate
equipment of the sort used in hospitals is quite unnecessary

for ethylene oxide sterilization He pointed out that ethylene
oxide is highly soluble in many plastics and there may be considerable
residual bactericidal activity after the ethylene oxide has removed
and some caution should be taken about this. The main conclusion
of the discuesion, and there was just no question about this, was
that very strong support should be given to the assignment of
technical direction for decontamination procedures to the Chemical
Corps Laboratories at Fort Detrick. These will include, in the
first instance, microbiological studies of the existent parts

as they go into the rockets, how effective ethylene oxide sterilization

iS on the components and the determination of the residual microbial
To

OFFICE MEMORANDUM ® STANFORD UNIVERSITY

Date:

From: LevemuLkG — GiNetics

SuB JECT: Page 2

Oe)

Decontamination Meeting

flora after surface sterilization is done on sealed components

such as condensers and transistors. Then these components can

be studied part by part to determine the most effective method

of sterilization each of them. For spot purposes, it may be
important to use techniques such as thermal and radiation
sterilization. On the whole, the assembly including the last

rocket stage is simply too large for easy handling by radiation
sterilization and there might be considerable question as to

the lability of electronic parts. However, for sealed components
this may prove to be a very important method. Derbyshire agreed

to write up the proceedings of t}is particular meeting for circulation
and action by the Space Science Board. It was understood that

this particular session was not concerned with the objectives of
sterilization so much as the tactics of achieving this. However,

it was necessary to spend about half the time of the session in
general discussion of these objectives in order to get a reasonable
orientation.

Dick Davies will be in London at the Astronautics Congress until
September 8th and would prefer that Westex be held after that tine
He is giving a paper on the decontamination question at the Congress.
A memorandum should be circulated to Westex during the next week

or two reporting this meeting, the developments on the Space Science
Board, and the BioAstronautics affiliation and also calling for

the comments on the position paper.

(Recall that Pollock had suggested Gause as a useful contact in
Moscow. Unfortunately, he was in London until fairly recently

but it will not be feasible for the moment to make contact with
him.

Derbyshire suggested setting up a Starford account for Space Board

expenses.

End.