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Subject: Stoddard solvent

Stoddard solvent

From: Alan Phenix <alan.phenix<-a>
Date: Tuesday, November 1, 2005
Stoddard Solvent and other hydrocarbon solvents:
Important Change to Hazard Classification in Europe

Further to my recent posting regarding changes in occupational
exposure limits in the UK, I have also come across another very
important development regarding health and safety that may have a
bearing on conservators.  This relates to the hydrocarbon solvent
known as Stoddard Solvent. In the UK at least, many conservators of
paintings, and probably other disciplines too, have probably used
this solvent routinely in place of white spirits bought for example
from a hardware store, for such purposes as varnishing, varnish
removal etc.  This has certainly been fairly common practice in
places where I have worked.   Stoddard Solvent complies with the
British Standard for white spirit (Type A. BS 245, 1976), and to an
old (pre-1996) ASTM standard for mineral spirits D235 Type 1.

We have been in the habit of buying Stoddard Solvent from the
laboratory chemicals and equipment supplier VWR International
(formerly Merck and BDH) who label their product as "Harmful" (Xn)
with the associated risk phrases of:

    R10     Flammable;

    R51/53  Toxic to aquatic organisms, may cause long term adverse
            effects in the aquatic environment;

    R65     Harmful: may cause lung damage if swallowed.

We had been in the habit of relying on, as the basis of our COSHH
(Control of substances Hazardous to Health) risk assessments, the
health and safety information provided by the manufacturer. The MSDS
sheets provided by VWR are dated 1996 and I realise now that these
are probably quite severely out of date.

Stoddard Solvent is assigned the CAS Registry Number 8052 41 3 and
the EC EINECS Number 232 489 3.  Whilst searching the various
hazardous chemicals databases of the EC I discovered, somewhat to my
alarm, that the European hazard classification of Stoddard Solvent
is crucially different from the "Harmful" label used by VWR, as are
the current health risk phrases.

Stoddard Solvent is now formally classified by the EC as Toxic
(symbol "T") and a Carcinogen Category 2; accordingly it carries the
health risk phrase R45   May cause cancer.  It is still also classed
as "Harmful" (Xn) which relates to the R65 risk phrase that
continues to operate.

I guess this demonstrates that one cannot necessarily rely too
strongly on suppliers for provision of essential information
regarding hazards presented by chemical substances, and we will
certainly have to rethink our usage of hydrocarbon solvents in the
light of this discovery.  I hope this information might be useful to
other people who use Stoddard Solvent.

The same concerns that I raise above about VWR's Stoddard Solvent
also probably apply to some other hydrocarbon solvents available
from laboratory chemical suppliers. For example, Sigma/Aldrich/Fluka
offer at least two hydrocarbon solvent products which appear   on
the basis of their CAS and EC numbers   to be wrongly
classified/labelled as far as health hazards are concerned.  These

    Cat. No. 77370. "Petroleum, purum, special, approximately 18% as
    aromatics, bp 180, 220 deg. C"  which is assigned the CAS number
    64742 82 1 and the EC Number 265 185 4.  These numbers class the
    product as "Naphtha (petroleum), hydrodesulfurized heavy", and

    Cat. No. 03881.  "Petrol, puriss., bp 150, 190 deg. C", CAS
    number 8032 32 4, EC #232 453 7, which classes the product  as
    "Ligroine, Low boiling point naphtha".

According to EC conventions, both these products should be
classified and labelled as "Toxic, Carc. Cat. 2; R45" and "Harmful,
Xn; R65", but actually only carry the "Harmful, Xn" warnings and
Risk phrases R52/53 and R65.

I have written to VWR and Sigma/Aldrich/Fluka to see what their
position is, and if I get any useful info I'll pass it on.
Sigma/Aldrich/Fluka at least appear to have the correct hazard
classifications for most of their other hydrocarbon solvent

But it occurred to me also that, since they conform to the same
British Standard BS245 1976, the ordinary commercial white spirit
that one might buy from a hardware store might be similarly
classified to Stoddard Solvent in the EC as "Toxic, Carc. Cat. 2;
R45".  I checked this with one leading supplier of
hardware/household grade white spirits who confirmed that this would
have been the case in the past; but he told me that, in response to
the new EC classification, they had changed their product to a (more
expensive) low aromatic grade.  Again, I am trying to find out more
about exactly what kind of product this might be (% aromatics,
boiling point etc.).  Presumably, this is a low aromatic content
white spirits supplied by one of the major petrochemical companies.
So there should not be the same concern about such household
products as there is now for Stoddard Solvent.

As many people no doubt recognize, the subject of the naming and
definition of hydrocarbon solvents broadly classed as "mineral
spirits" is rather confusing (especially in English: I hope to be
able to provide some clarification on terminology shortly.).  The
World Health Organization identified four main types of white spirit
(in addition to Stoddard Solvent) that are used around the world,
each indicated by particular CAS Registry numbers and EC
chemicals/EINECS numbers, as follows:

    white spirit type 0;
    CAS 64742 88 7, EC# 265 191 7.
    Substance Name under ECB Annex 1 "Solvent naphtha (petroleum),
    medium aliph.  Straight run kerosine".

    white spirit type 1;
    CAS 64742 82 1, EC# 265 185 4;
    Substance Name under ECB Annex 1  "Low boiling point hydrogen
    treated naphtha  Naphtha (petroleum), hydrodesulfurized heavy".

    white spirit type 2;
    CAS 64741 92 0, EC# 265 095 5;
    Substance Name under ECB Annex 1  "Low boiling point modified
    naphtha,  Naphtha (petroleum), solvent refined heavy".

    white spirit type 3;
    CAS 64742 48 9, EC# 265 150 3;
    Substance Name under ECB Annex 1 "Low boiling point hydrogen
    treated naphtha  Naphtha (petroleum), hydrotreated heavy"

Importantly, the last three of these types are all now classified in
Europe, like Stoddard Solvent, as "Toxic", "Carc. Cat. 2" and carry
the Risk Phrase "R45: May cause cancer."

Only the first, white spirit type 0 (64742 88 7), is not classified
in that way: rather, it is just classified as "Harmful, Xn; R65 may
cause lung damage if swallowed". People using hydrocarbon solvents
might be advised to check the CAS or EC numbers of the products, if
available from the supplier, to check if they correspond to any of
these last three types.

It appears that understanding of what is meant by the term "Stoddard
Solvent" differs between America and Europe.  (In fact, I would be
interested to hear from anyone about how they would define and use
the term "Stoddard Solvent").  In the United States,  "Stoddard
Solvent" seemingly can be used to describe any hydrocarbon solvent
used for its original purpose of dry cleaning.

The US lab chemicals supplier, Fisher Scientific, supplies a
"Stoddard Solvent" product under the CAS Registry number 64742 88 7,
which, reassuringly, places it in the type 0 category of white
spirit which is only classified as "Harmful, Xn".

Alan Phenix
Senior Lecturer, Conservation of Fine Art,
Northumbria University,
Newcastle upon Tyne
(temporarily guest scholar at GCI)

                  Conservation DistList Instance 19:24
                Distributed: Thursday, November 3, 2005
                       Message Id: cdl-19-24-001
Received on Tuesday, 1 November, 2005

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