|
The
requirement for periodic retest of combination packages is stated
in paragraph 178.601(e) of Title 49 CFR and must be repeated every
two years for as long as the design remains active. Reading further
in this section, paragraph 178.601(g) allows a number of selective
testing variations. Understanding how to apply these variations
to maximize product and container improvements can save manufacturers
of hazardous material thousands of dollars in shipping costs and
testing fees.
There are five variations described in paragraph 178.601(g), Variations
1, 2 & 4 apply to combination packages. These variations explain
the changes to inner and outer packagings that are permitted without
further testing. It is important to remember that for air transport,
packagings must comply with paragraph 173.27(c)(1) and (c)(2)
of Title 49 CFR.
For many, these variations are difficult to interpret. They must
rely on consultants or an authorized third party laboratory to
determine what type of package changes are permitted without testing
and what changes definitely require additional testing. DDL was
among the first group of laboratories to become a Package Certification
Agent (PCA) authorized by the Department of Transportation (DOT).
Through active membership participation in related associations
and years of experience the HazMat engineers at DDL have developed
a comprehensive understanding of these regulations and have certified
hundreds of packages for the transport of hazardous material and
dangerous goods.
What constitutes a design change?
A design change is defined as any change to a package, or it's
constituent parts, that are not identical to the original design
that was tested. This definition leads us to believe that any
changes to the package design after it has been tested and certified
are not acceptable. This is not necessarily true.
Many letters of interpretation have been submitted to DOT addressing
some of the issues faced by manufacturers. Much of the uncertainty
is due to the fact that some of the selective testing variations
are too vague in describing what is permissible and what is not.
For example, Variation 1, paragraph (C) states that "further
testing would not be required on inner packagings of equivalent
or small size provided the packagings have the same or smaller
openings and the closure is of similar design (e.g., screw-on
cap, friction fit, etc.)." This does not take into account
the liner material, which will have a direct impact on whether
the package will pass or fail the test. This is just one example
of the things to consider when changing components in a package
during the certification period.
As a third party laboratory, DDL receives many requests to assist
in clarifying and interpreting selective testing variations. The
most frequently asked question is - "If I make a particular
component bigger, better, or stronger, am I required to do additional
testing?" Unless you can prove that the component is virtually
identical to the tested component, the answer to this question
is YES. Virtually identical does not mean better or stronger .
. . it means identical.
Another question that gets asked is - "Can I switch vendors
at any given time during the certification period?" The answer
is NO; you may not switch vendors unless, once again, you can
prove that the new vendor is manufacturing a virtually identical
component as the current vendor. Manufacturers can develop controls
to provide such proof by writing precise specifications for each
component thereby mitigating inconsistencies between vendors and
assuring that components are virtually identical. Having tight
specifications will also prevent vendors from making changes without
first obtaining permission.
Well-defined specifications are particularly important when changing
to a different corrugated vendor. DOT places considerable emphasis
on the basis weight of corrugated boxes, which has become an important
factor when comparing one vendor to another. Other important factors
that must be specified are burst value or edge crush value, fluting,
dimensions, Cobb test data and wall construction (single-wall,
triple-wall, etc.). However, manufacturers must be made aware
that if all specifications are identical except for the basis
weight, additional testing must be performed. As transporters
of hazardous material or dangerous goods, manufacturers are accountable
for their decisions; therefore it is important that they be able
to demonstrate that all components are virtually identical when
switching vendors.
Other notable (but not all) changes that would require additional
testing are;
- changing
the wall thickness of the primary container,
- changing
the production method of the primary container (e.g. switch
from blow molding process to a rotational molding process),
- switching
closure types (e.g. screw-on cap to a welded cap),
- adding
components (adding a liner to a 55 gallon drum after testing),
- changing
the method in which your package design closed, and,
- changing
plastic resin.
Although selective
testing variations have allowed some flexibility in the package
design process, there are still many instances where manufacturers
need assistance in interpreting the regulations. Third party testing
laboratories and consultants are a good source for answers to
these questions; however DOT is still the best choice because
you get the information from those individuals that are directly
responsible for enforcing the regulations.
When in doubt about which changes are permissible and which are
not, it's best to take a conservative approach and assume that
retesting is required - at least until you can find enough supporting
evidence to prove otherwise. When it comes to a shipment of hazardous
materials, it is always better to be safe than sorry. DOT is out
there checking and levies thousands of dollars in fines each month
to unwary shippers.
When is testing NOT necessary?
There are many a situation in which retesting is required. Likewise,
there are an equal number of situations in which no additional
testing is needed. The selective testing variations found in section
178.601(g)(1 thru 5) allow minor changes to occur within a package
design without retesting. Remember the definition of a design
change as; ". . . any change to the original design that
was tested." It has already been established that certain
changes may not necessitate additional testing. The following
paragraphs address a few common questions encountered by DDL engineers
and provide explanations as to why they are acceptable under the
selective testing variations.
This scenario addresses whether a single 1-gallon bottle can be
used in shipment for a package design that was certified using
a 4 x 1-gallon configuration. The answer is YES, provided that
all conditions of Variation 1 in paragraph 178.601(g)(1) of Title
49 CFR are met.
Changes would be permitted if;
- the 1-gallon
bottle is of similar design,
- similar
construction and material are used,
- it has
the same or smaller openings,
- sufficient
additional cushioning is used to fill in voids,
- orientation
of the inners is maintained, and,
- the certified
gross mass is not exceeded.
In addition,
the size of the shipper may be reduced to accommodate the 1-gallon
bottle provided Variation 4 in paragraph 178.601(g)(4) is met.
Variation 4 states that the shipper must have;
- smaller
dimensions than the tested design,
- the structural
design and method of closure are maintained,
- the inner
packaging is identical (or smaller) and lighter than the tested
design,
- the same
cushioning is used, and,
- sufficient
additional cushioning is used to fill in voids.
By allowing
shippers to mix inner packagings among design types tested with
different inner packagings; these two variations permit great
flexibility to manufacturers, especially for combination packages.
Other changes allowed under the selective testing variations include;
- switching
colors of the materials tested provided the components are virtually
identical,
- smaller
inner containers, either by size or volume, can be used provided
the largest bottle is tested and is virtually identical,
- if a drum
contains two closure styles and it is tested that way, it is
permissible to switch to only one of the closure styles tested.
For combination
packages, Variation 2 offers one way for manufacturers to avoid
having to decide on which changes are permissible and which are
not. Variation 2 parameters, as described in paragraph 178.601(g)(2),
allows anything to be packed inside of the package provided the
gross mass of the outer package plus on-half the mass of the filled
inner packagings of the tested package is not exceeded. The disadvantage
of this variation is that the testing requirements are extremely
severe and it is very specific in how the package needs to be
prepared for shipment. This is a classic case of convenience vs.
flexibility.
Although this does not necessarily pertain to selective testing
variations, here is another point worth mentioning because it
gets asked on occasion - "Is retesting required when the
certification expires?" The most obvious answer to this is
YES, however there is one exception; if a manufacturer has previously
certified packages in inventory, retesting is not required until
the inventory has been depleted.
Conclusion
Determining whether a selective testing variation is applicable
to meet your current needs can be difficult and unclear at times.
Correctly interpreting the regulations becomes even more critical
knowing that the DOT is constantly screening packages at a place
called Tobyhanna Engineering and Testing Facilities, a third party
testing laboratory used by DOT's Research and Special Programs
Administration (RSPA) to determine if packages were correctly
certified. This system of checks and balances is in place to make
sure that the regulations are followed and properly applied to
each type of package. Determining whether a package would fall
under the selective testing provisions can be a tricky. Keeping
these three things in mind will help you make good decisions;
1) remember the phrase "virtually identical" and the
defining parameters, 2) remember that you are ultimately responsible
and liable for the decisions you make, and 3) when in doubt, contact
the HazMat engineers at DDL for assistance.
This article
is reprinted with the permission of Hazmat Packer & Shipper™
and has been rewritten and up-dated by Dick Strand, DDL, Incorporated.
|
