Document NI-9912 reduces to naught all the supposed “witnesses’ accounts”, without exception, on the use of Zyklon B to kill human beings.
Remarks on the document
It comes from the archives of the Nuremberg trials. It was registered by the Americans at a late date: August 21, 1947, in the “NI” category (Nuremberg, Industrialists). It was taken from the archives of the Degesch company and listed under four headings, among which that of “Atrocities” (sic). I reproduce it below in near facsimile with a few slight corrections.
The original, in the form of four large pages to be posted on walls, was a notice that must have been distributed in a great many copies; the specimen translated here was issued by the Prague Health Authority, doubtless in the midst of the war. The contents show that its purpose was to convey instructions for the use of Zyklon (prussic or hydrocyanic acid) to destroy vermin in buildings which could be either civil or military (apartment blocks, barracks, etc.). The document fittingly reminds us of a truth learnt from experience: of all deadly weapons, gas will probably long remain the most unwieldy; when it kills, it kills so well that it can be fatal to the killer who decides to use it. If it is quite easy to kill with prussic acid, it is also quite difficult to kill anyone nearby without running terrible risks oneself.
This document describes the properties of Zyklon, its risk of explosion, its toxicity. Only persons possessing a certificate obtained after special training may use the product. A gassing’s planning and preparations call for measures and tasks requiring several hours, possibly days. Then comes the operation itself. Among many details we note here that Zyklon is not to be poured out into a pile or through the air. To produce the desired effect it must be spread thinly on paper mats; none of it is to be lost anywhere: all will be recovered in due course. It will take from six to thirty-two hours to kill the pests (sixteen hours on average). Then will come the most critical moment, that of aeration. The text says: “Aeration presents the greatest danger for both participants and non-participants. It is therefore necessary to proceed with particular caution, and always wearing a gasmask.” This aeration will have to last “at least twenty hours”. Sentries, during all that time and even afterwards, must remain near the building. To make sure that no gas remains, the specialists, again in gasmasks, enter the premises with a strip of paper that will indicate the presence of any residual gas. Twenty hours previously, the simple opening of doors and windows, as well as easy tasks of moving “planking and sealing items” (an effort amounting to nothing compared with the dragging away of hundreds or even thousands of corpses) had presented a certain danger – that inherent in a possible acceleration of the breathing – since, after the aeration of each floor, the team had had to go outside, remove their masks and breathe fresh air for at least ten minutes. All the rest is in a similar vein and I leave it to the reader to discover in each line of this document how absurd by comparison the stories of our false witnesses are. [R. Faurisson’s note]
TRANSLATION OF DOC. No. NI-9912
Office of Chief of Counsel for
DIRECTIVES FOR THE USE OF PRUSSIC ACID (ZYKLON)
FOR THE DESTRUCTION OF VERMIN (DISINFESTATION).
- Properties of prussic acid. (hydrocyanic acid)
Prussic acid is a gas which is generated by evaporation.
Boiling point: 26 degree Centigrade.
Freezing point: – 15 degrees Cent.
Specific gravity: 0.69
Steam density: 0.97. (Air: 1.0)
The liquid evaporates easily.
Liquid: transparent, colourless.
Smell: peculiar, repulsively sweet.
Extraordinarily great penetrative powers.
Prussic acid is soluble in water.
Danger of explosion. 75 g prussic acid 1 cbm air. (Normal
application approx. 8-10 g per cbm, therefore not explosive).
Prussic acid may not be brought into contact with an open
flame, glowing wires etc., because then it burns up slowly
and loses all its effectiveness. (carbonic acid, water and
nitrogen are formed).
Toxic effects on warm-blooded animals.
Since prussic acid has practically no indicative irritant
effect it is highly toxic and very dangerous. Prussic acid
is one of the most powerful poisons. 1 mg per kg of body
weight is sufficient to kill a human being. Women and
children are generally more susceptible than men. Very
small amounts of prussic acid do not harm the human body,
even if breathed continuously. Birds and fishes are
particularly susceptible to prussic acid.
Toxic effects on insects.
The effects of prussic acid on insects do not depend on
the temperature to the same extent as that of other gases,
TRANSLATION OF DOC. NO.
that is, it is also effective in low temperatures (even at
5 degrees Cent.) The eggs of many insects, particularly of
bugs and lice, are more susceptible than the full-grown
Toxic effects on plants.
The degree of toxicity depends on the type of vegetation
on the plants. Plants with thick leaves are less susceptible
than those with thin ones. Mildew and dry-rot are not
killed by prussic acid. Prussic acid does not destroy bacteria.
II. Method of using prussic acid.
ZYKLON is the absorption of a mixture of prussic acid and an
irritant by a carrier. Wood fibre discs, a reddish brown
granular mass (Diagriess – Dia gravel) or small blue cubes
(Erco) are used as carriers.
Apart from serving its purpose as indicator, this
irritant also has the advantage of stimulating the respiration
of insects. Prussic acid and the irritant are generated
through simple evaporation. Zyklon will keep for 3 months.
Use damaged cans first. The contents of a can must all be
used up at once. Liquid prussic acid damages polish, lacquer,
paint etc. Gaseous prussic acid is harmless, The toxicity
of the prussic acid remains unchanged by the addition of the
irritant; the danger connected with it is however
Zyklon can be rendered [omitted: inoffensive] by combustion.
III. Possible poisoning.
1. Slight poisoning:
Dizziness, headache, vomiting, general feeling of
sickness, etc. All these symptoms pass if one immediately
gets out into the fresh air. Alcohol reduces resistance to
prussic acid gassing, therefore do not drink alcohol before
Prescribe: 1 tablet Cardiazol or Veriazol in order to
prevent heart disorders, if necessary repeat after 2-3 hours.
2. Severe poisoning.
The affected person will collapse suddenly and faint.
First Aid: fresh air, remove gas mask, loosen clothing,
apply artificial respiration. Lobelin, intermuscular 0.01g.
Do not give camphor injections.
(page 2 of original [translator’s note])
Poisoning through the skin.
Symptoms as for 1. Treat in the same way.
4. Stomach poisoning.
Lobelin intermuscular 0.01g.
IV. Protection against gas.
When fumigation with Zyklon use only special filters,
e.g. the filter insert “J” (blue-brown) of the Auergesell-
schaft Berlin or of the Draegerwerke, Luebeck. Should gas
seep through the mask, leave the building immediately and
change filters after also checking the mask and its fit to
see whether they are tight. The filter insert is exhausted
if gas enters through the mask. If using filter “J”, first
move around in the open air for approx. 2 minutes so
that a certain amount of moisture from the breath may gather
in the filter insert. Under no circumstances should filters
be changed inside gas-filled rooms.
A disinfestation squad consisting of at least 2 members
is employed for each disinfestation project. The fumigation
chief is responsible for the fumigation. His particular
duties are inspection, airing, release and safety measures.
The fumigation chief is to appoint a deputy in case he has
to leave. The orders of the fumigation chief are to be
followed without delay.
Untrained persons or persons who are trained but who
do not yet hold a certificate may not be called in to work
on gassing operations, nor may they be taken into gas-filled
rooms. The fumigation chief must also know where to contact
his personnel. Every person must at all times be able to
prove that he has official authorization for the use of
prussic acid for extermination purposes.
Each member must at all times carry with him:
1. His own gas mask.
2. At least 2 special filter inserts against Zyklon
3. The leaflet “First Aid for prussic acid poisoning.”
4. Work order.
5. Authorization certificate.
Each disinfestation squad must at all times carry:
1. At least 3 special inserts as extra stock.
2. 1 gas detector.
3. 1 instrument for injecting Lobelin.
4. Lobelin 0.01g. ampules.
5. Cardiazol, Veriazol tablets.
6. 1 lever or pickhammer for opening the cans of Zyklon.
7. Warning signs as per regulation.
8. Material for sealing.
9. Sheets of paper to serve as pads.
TRANSLATION OF DOC. NO.
All equipment is to be kept clean and in good order at all times. Damage
to equipment is to be repaired at once.
VII. Planning fumigations.
1. Can the fumigation be carried out at all?
a) Type of building and situation.
b) Condition of roof.
c) Condition of Windows.
d) Presence of heating shafts, air shafts, breaks in
the walls etc.
2. Determine the kind of vermin to be exterminated.
3. Calculate the space. (Do not rely on drawings but take measurements yourself. Take only outside measurements, include walls)
4. Prepare personnel.
(Remove domestic animals, plants, food and drink, undeveloped photographic plates and gas mask filters.)
5. Find which opening will be particularly difficult to seal.
Air shafts, drains; large openings which have been
boarded up, roofs.
6. Settle necessary safety measures.
(Guarding, work detachment for sealing)
7. Fix the date for the fumigation and the time for clearing the building.
8. If necessary, arrange safety measures for the neighbourhood in good time.
9. Notify authorities.
VIII. Preparation for fumigation:
2. Open all doors, closets, drawers, etc.
3. Pull bedding apart.
4. Remove all liquids (remains of coffee, washing water etc.)
(page 3 of original [translator’s note])
5. Remove all food.
6. Remove all plants and domestic animals (aquaria etc.)
7. Remove all undeveloped photographic plates and films.
8. Remove adhesive plaster, all medical supplies, whether
open or in paper bags (particularly coal).
9. Remove all gas mask filters.
10. Prepare for check on results.
11. Clear out personnel.
12. Take over keys (every door key)
IX. The strength of the gas and time required for it to take
effect depend on
the type of vermin
the amount of furniture in the rooms
the imperviousness of the building
For inside temperatures of more than 5 degrees Cent. it is
customary to use 8 g prussic acid per cbm.
Time needed to take effect: 16 hours, unless there are
special circumstances such as a closed-in type of building,
which requires less time. If the weather is warm it is
possible to reduce this to a minimum of 6 hours. The period
is to be extended to at least 32 hours if the temperature
is below 5 deg. Cent.
The strength and time as above are to be applied in
the case of: bugs, lice, fleas etc., with eggs, larves and
For clothes-moths: temperatures above 10 deg. Cent.
16 g per cbm and 24 hours to take effect.
For flour-moths: same as for bugs.
X. Fumigation of a building.
TRANSLATION OF DOC. NO.
- Check that everybody has left the building.
- Unpack the boxes of Zyklon. Make the appropriate amount
ready for each floor.
- Distribute the cans. One man to go into the building
and receive the cans which have been brought up by the work
detachment and to distribute them. (Have them put next to
- Dismiss the work detachment.
- Post the guard. Fumigation chief to instruct guard.
- Check that sealing and clearing have been completed.
- Put on gas masks.
- Open the cans and pour out their contents. The contents
are to be spread thinly so that the Zyklon can evaporate
quickly and the necessary density of the gas can be achieved
as soon as possible. This process is to start on the top
floor but the cellar is to be dealt with before the ground
floor, should the cellar have ne exit. Rooms which have been
dealt with should as far as possible not be re-entered.
The processing is to be done slowly and calmly. The
staircase particularly should only be used slowly. The
processing may only be interrupted in an emergency.
- The exit door to be locked, sealed
[omitted:do not forget the lock]
and its key handed
over to the fumigation chief.
- On the door fix a warning sign with the legend “Danger-Poison gas. Danger to life; no admittance.” This warning
sign is to be in several languages if necessary, and in any
case it must be marked with at least one death’s head,
- Gas masks, apparatus for resuscitation and gas detectors
are to be kept available at all times. Every member of the
fumigation squad must know where these objects are located.
TRANSLATION OF DOC. NO.
- At least one member of the fumigation squad must always remain near the building which is being fumigated. The
guard must be notified of his position.
The airing is connected with the greatest danger for those participating and others. Therefore it must be carried out particularly carefully and a gas mask should always be
worn. The airing should place according to the following principles: pure air should always be within reach in the shortest possible time and the gas should flow out to that
side where it cannot endanger people who are not participating. Should the airing be difficult one trained man should remain in front of the building in order to watch how the gas is blowing away.
- Take care to see that no strangers remain in the vicinity of the building.
- Post the guards in such a way that they are not annoyed
by the gas as it blows out, but can still watch the entrances to the building.
- Put on gas mask.
- Enter building. Close door, but do not lock it.
- First open the windows on that side of the building
where there is no wind. Air floor by floor. Start on the
ground floor and after each floor take at least 10 minutes’
- Doors leading to the corridor, connecting doors
between rooms and windows must be opened in each room.
Should there be difficulty in opening any of the windows
they should only be opened after most of the gas has blown away.
(page 4 of original[translator’s note])
- Partitions and other methods used to seal the room
which cannot be replaced quickly should only be removed
after most of the gas has blown away.
- Care should be taken to see that the heating system and
water pipes do not freeze should there be frost or danger
- Rooms with valuable contents, such as clothing stores
etc. may be locked again after [sic, for as soon as]
the windows have been opened.
- Windows and doors which have been opened should be
fastened in such a way that they cannot slam.
- Covers in chimneys may be removed after the provisional
release [sic, for clearance] of the building.
- The airing should continue for at least 20 hours
- The guard should remain near the building during the
whole of this time
XII. Provisional release.
A fumigated room may be released provisionally as
soon as the paper strip of the gas detector is of a lighter
blue than the centre colour pattern, when the doors and
windows are open. Only work concerned with airing and
clearing up may be done in the rooms which have been
provisionally released. Under no circumstances may anyone
rest or sleep in these rooms. The doors and windows must
be left open all the time.
XIII. Clearing up after provisional release.
1. Remove remains of Zyklon from the fumigated rooms.
They should generally be sent back to the factory in the
same way as cans and boxes. Before boxes are sent back
from the fumigated rooms the inscription “Poison” must be
removed from them. Damp, wet or soiled remains as well as
damaged cans may not be sent back under any circumstances.
They may be thrown on a rubbish or slag heap, but may never
be emptied into drains.
2. Mattresses, straw palliasses, pillows: upholstered
furniture and similar items must be shaken or beaten for at
least one hour in the open air (if rainy at least 2 hours
in the hall) under the supervision of the fumigation chief
[omitted: or his deputy].
3. If possible the stuffing of straw palliasses should be
changed. The old stuffing may not however be burnt, but
may be re-used after it has been aired for a further period.
4. Should the chimneys have been covered from above,
these coverings must be removed carefully since otherwise
there is a danger that the fires in the stoves and hearths
will not have sufficient draught, which may cause carbon
5. After the final release has been made, two copies of a
fumigation report are to be filled in in the prescribed
manner. The following points in particular should be shown:
a)Volume of fumigated rooms.
b)Amount of Zyklon used.
c)Name of fumigation chief.
d)Names of other personnel.
e) Time required for gas to take effect.
f) Time at which dis-infested rooms were released.
XIV. Final Release.
1. Under no circumstances less than 21 hours after airing
2. All items removed for beating are to be taken back into
3. Doors and windows to be closed for one hour.
4. In rooms with heating facilities a temperature of at
least 15 deg. Cent. must be produced.
TRANSLATION OF DOC. NO.
5. Gas detecting. The paper strip may not show a darker
blue than the lightest colour even between blankets and
mattresses which have been placed on top of each other,
or in rooms which are not easily accessible and which it
is difficult to air. Should this not be the case, airing
must be continued and the check for gas repeated after a
6. The check for gas must be made in each room of buildings
which are again to be used as sleeping accommodation as
soon as possible. Under no circumstances may anyone sleep
in a room which has been fumigated in the night following
the fumigation. The windows must always remain open during
the first night that the room is used again.
7. The fumigation chief or his deputy may not leave the
building until the very last room has been finally released.
Issued by the Health Institution
of the Protectorate Bohemia and
Moravia in Prague.
CERTIFICATE OF TRANSLATION.
I, DOROTHEA L. GALEWSKI, ETO # 34079, hereby certify
that I am thoroughly conversant with the English and
German languages; and that the above is a true and
correct translation of Document No. NI-9912.
DOROTHEA L. GALEWSKI