Example of a Limited Quantity exemption
- ethanol in a passenger vehicle in Canada
The quantity
limit and packaging requirements depend on the characteristics
of the item. I have included an example for transporting ethanol
solutions via passenger vehicle. Individuals can do their own
analysis for items they may wish to transport. For further information,
you might check with Gordon Weir of the University of Alberta
Office of Environmental Health and Safety who does training for
TDG.
1. Find out
what Packing group (PG) the item is in:
Examine
Part III "Safety Requirements for Classification"
in the TDG
Regulations.
There are
nine classes of dangerous products and some have subdivisions:
1. Explosives
2. Compressed Gases
3. Flammable Liquids
4. Flammable Solids
5. Oxidizers and Organic Peroxides
6. Poisonous and Infectious Substances
7. Radioactives
8. Corrosives - acids and bases
9. Miscellaneous Dangerous goods - includes environmentally
hazardous substances
Ethanol is
a flammable liquid so is in Class 3. Packing Group II has
a boiling point (bp) >35C and a flash
point <23C. You could find information on the boiling point
and flashpoint by reading the Material Safety Data Sheet (MSDS,
if you don't know what this is, you better sit in on the next
WHMIS seminar). Ethanol (100%) has a boiling point of 78C and
a flash point of 13C so it is in packing group (PG) II. An ethanol
solution that is about 55% (vol/vol) has a flash point around
21C so any ethanol solution between 55% and 100% falls into PG
II. Packing Group III liquids have a bp >35C and a fp between
21 and 61C. For ethanol solutions, this corresponds to a concentration
of between 5 and 54% ethanol in water.
Thus solutions
containing between 55% to 100% ethanol are in PG II and solutions
that are between 5% to 54% ethanol are in PG III.
2. What is
the Limited Quantity size for flammable liquids in PG II
and III?
Consult
Schedule VIII in the regulations and in Table 3
we find for primary classification 3 and packing group II that
the limited quantity depends on the inner packaging used
(i.e. the container holding the item). For a glass or plastic
vessel, the quantity is 500 mL but for a metal container, the
quantity is 1L. Several individual limited quantities can be packed
in a cardboard box or a plywood box with a gross mass <30 kg
and the entire package would be a limited quantity of ethanol
and not subject to the full requirements specified in the TDG
regulations (other than those listed in part 2.7.1).
So, if
you packaged 20 glass 500 mL bottles of ethanol in a cardboard
box and the total mass of the box and contents was <30 kg,
the box would qualify under the limited quantity exemption.
If you had metal containers, the individual units could be 1L
in volume.
For ethanol solutions in the PG III category (i.e. 5-54%
ethanol in water), Table 4 in Schedule VIII indicates the
inner packaging size is 500 mL for glass or plastic bottles, but
is 5L for metal cans. Again the total mass of the entire package
must be <30kg to qualify for the limited quantity exemption.
3. What about
other flammable liquids?
It is the
packing group that determines the size of the inner packaging.
Some other members of PG II among the flammable liquids
include: pentane, hexane, gasoline, propanol and methanol. Other
members of PG III are: xylene, turpentine, kerosene, acetic acid
and formaldehyde (37% solution). PG I contains things like diethyl
ether, acetaldehyde and propylene oxide (all highly flammable)
and according to Schedule VIII, they are not allowed in limited
quantities, i.e. you must comply with all the TDG regulations
including being certified if you want to transport these items.
4. What about
a 100 g of sodium hydroxide?
Figure it
out for yourself. You should be learning more about the hazards
associated with dangerous products if you plan on working with
them or transporting them. Get your supervisor to help you since
they have a responsibility for your training with respect to hazardous
materials.
Notes:
Flash Point
(fp):
The flash point is the temperature at which the liquid gives off
sufficient vapours to be ignited. Below this temperature, they
do not produce enough vapours to from a combustible mixture with
the air. The lower the flash point, the easier it is to have a
combustible mixture at room temperature. Example: gasoline has
a flash point of -38C (which is why it is hard to start your car
at -45C) while kerosene has a flash point of +38C. At ambient
temperatures, it is harder to start kerosene on fire than gasoline,
however, both are flammable liquids.
For further
information on Flammable
and Combustible liquids, go to the Chemical Safety section
of this site.
|
