[Histonet] Re: Xylene substitute

[Robert Richmond]

Questions about xylene substitutes: This has been discussed a good
many times on Histonet.

There are two classes of xylene substitutes:

Limonene and turpentine are terpenes. Several brands; AmeriClear was
mentioned. Limonene is prepared by steam distillation of orange peels.
It has a strong citrus smell variously described as pleasant,
overwhelming, disgusting, and allergenic, and cannot be made odorless.
It is not very toxic, is not easily set afire, and is to a degree
biodegradable. It cannot be distilled. With America's declining citrus
industry, this once cheap product has become considerably more
expensive.

Aliphatic solvents are now in much more widespread use. They are more
expensive than xylene, but can be recovered by distillation. Most of
them are odorless, at least to my nose. They are not very toxic. Some
have much lower flash points than others, so that fire hazard varies
considerably. They are not easiy biodegradable. Different brands
differ considerably in chemical and physical properties, and
distillation routines for one brand cannot be used with another brand.

Richard Allan's Clear-Rite 3 may be the most widely used aliphatic.
ANATECH's Pro-Par was mentioned in this correspondence, and is very
meticulously described on their Web site.

I hadn't heard of CBG Biotech's Formula 83 before. Slightly different
from ordinary aliphatics, it is described as a "naphthenic hydrocarbon
blend" (cycloalkane). It is described as "smells  like ether", and I
would be concerned about its very low flash point (45 F, below room
temperature, as described in the MSDS).

When you mention who makes a commercial product, please tell us who
makes it, and read the Materials Safety Data Sheet (MSDS) at the
product's Web site and see what you can find out what's in it.

I have no commercial connection with any product I've mentioned.

Bob Richmond
Samurai Pathologist
Knoxville TN