Nitrate-base film identification

It is my understanding that the definitive way to test whether a
negative has a nitrate-base is to place a small piece of it in
trichloroethylene to see if it will float.  As trichloroethylene is
rather toxic I would rather stay away from it if I could, but the true
nature of some negatives in our collection must be determined.

1.  Is there another way to test for nitrate-base negatives?

2.  Are there any agencies that will test negatives for you?

3.  Now do you safely dispose of trichloroethylene?

I ask the last question because if I have to do the testing I must
purchase 500ml of trichloroethylene, which is about 450ml more than I
need.  I might mention that the negatives in question are all from the
same source and where taken within the same time period.

    **** Moderator's comments:   Check CoOL, especially for an article
    by Andrew Robb and Monique C. Fischer "Guidelines for Care &
    Identification of Film-Base Photographic Materials"

Frank A. Reynolds
Hunt Institute
Carnegie Mellon University

                                  ***
                   Conservation DistList Instance 8:2
                   Distributed: Friday, June 17, 1994
                        Message Id: cdl-8-2-013
                                  ***