Page 7 - Combined_8_OCR

Tolylene Diisocyanate Manufacturing Chemists' Association, Inc. Manual
Sheet
SD-73
0

7.2.2.2.2 If the powder is not available, be completely drained and all openings (for bungs,
empty drums may be decontaminated by placing plugs, removable heads, etc.) tightly closed with
them in an open area out of doors and filling with gaskets in place. Care should be taken that no
water. Allow to stand at least 48 hours. Bungs moisture is present because carbon dioxide forma­
must not be replaced on drums containing water. tion could rupture the drum.
7.2.2.3 Spills Where Use of the Powder is When metal drums are to be scrapped, they
U ndesirable should be steamed in a well ventilated area to convert
any residual tolylene diisocyanate to solid urea.
In some cases the use of neutralizing powder Drums should then be crushed or pierced to render
is undesirable. An example of this would be when them impossible for re-use.
tolylene diisocyanate is running over process equip­
ment or piping. The best method of handling this
type of spill is to spray the isocyanate with a mixture 7.4 TANK TRUCKS
of 50% ethanol, 40% water, and 10% concentrated 7.4.1 It is preferable that tank truck unloading
ammonia solution. ‘This mixture will neutralize the facilities be level and paved and so located that the
isocyanate completely and will then evaporate, leav­ truck can be easily and safely maneuvered to the
ing an odorless residue. Care should be exercised unloading spot.
in using this mixture as its vapors are flammable.
The mixture should not be used where it could be 7.4.2 Ordinarily all operations concerning the
ignited by an open flame or a spark. Ammonia tank truck and its fittings, pumps, and hoses are the
fumes will be given off, but these are not nearly as responsibility of the tank truck operator. Therefore,
objectionable as tolylene diisocyanate vapors. the unloading operation should be carried out by
properly instructed employees in cooperation with
A mixture of 10% aqueous ammonia containing the driver.
an emulsifying agent such as mahogany soap has also
been used successfully. This mixture does not pre­ 7.4.3 Truck brakes should be set and, if neces­
sent the possible fire hazard introduced by the use sary, the wheels blocked.
of the ethanol-water-ammonia solution.
7.4.4 The shipper should be consulted on proper
o 7.3 DRUMS unloading procedure.,

7.3.1 Handling
7.5 TANK CARS
Drums should be unloaded and handled care­
fully to prevent damage. Each shipment should be 7.5.1 Unloading
carefully examined for leaking drums. If any is 7.5.1.1 The unloading of tank cars of tolylene
found, it should be removed to some well ventilated diisocyanate should be done only with competent
area, preferably outdoors, and the contents trans­ supervision. Detailed recommendations regarding
ferred to a suitable container. unloading procedures set forth in the Manufacturing
Chemists’ Association Manual Sheet TC-4 is a de­
Workmen responsible for opening or closing
drums should wear the appropriate protective equip­ pendable guide to assist unloaders in performing
ment (see Section 5.2). this operation safely.
7.3.2 Emptying 7.5.1.2 The following information should also
be kept in mind:
Drums should be well-secured and blocked
before emptying. (a) It may be necessary to heat the tank car
before unloading tolylene diisocyanate. The 2,4
To remove the body plug from a drum of isomer will begin to freeze out at about 70°F., and
tolylene diisocyanate, the operator should use a the entire contents of the tank car will solidify if
bung or plug wrench. He should place the bung the temperature is lowered. A 25-75 psi steam
up, stQnd to one side, and face away during the supply should be attached to the steam cpil on the
operation. After the bung starts to loosen, it should tank car, and the tolylene diisocyanate should be
be given not more than one full turn. If internal heated to 75-80° F. (24-27° C.)
pressure exists, it should be allowed to escape to
the atmosphere. After all pressure has been vented (b) It is essential that the tank car be padded
off, the operator can loosen the plug further and with a dry atmosphere at all times. If this is not
remove it. done, any water vapor that might be present will
react with the isocyanate, forming a solid urea ma­
7.3.3 Disposal
terial. This may result in plugging of lines and
o Metal drums to be returned to suppliers should will result in loss of tolylene diisocyanate. Nitrogen

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