o-TOLUIDINE CAS N°: 95-53-4 - UNEP Chemicals

OECD SIDS o-TOLUIDINE
methylene-bis-2-methylcyclohexylamine, fungicide intermediates such as 2-amino-4-methylbenzothiazole,
o-fluorobenzoyl chloride, and some pharmaceutical intermediates (Bowers, 2002).
o-Toluidine is also used for the photometric determination of glucose in blood (Roempp, 1999).
No direct consumer use is known for o-toluidine (Bayer Chemicals, 2004). o-Toluidine is contained
in products listed in the Danish, Finnish, Norwegian, and Swedish Product Registers (SPIN, 2004).
No consumer application is registered. In the Finnish Product Register there is a confidential listing
that o-toluidine is used for the manufacture of rubber and plastic products as a vulcanizer and for
other use. For the Danish Product Register there is a listing as a process regulator in 2000 and 2001
(the latest year of reporting). According to this register, in total “0.0 tonnes” of o-toluidine were
used in 2001, signifying that o-toluidine is not added intentionally into these processes.
The Swiss Product Register (2004) lists 2 public products (analytical kits), both with an o-toluidine
concentration of about 0.1 %. Although both analytical kits are listed as public products, it is
assumed that these products are used industrially. Another similar product, an analytical substance,
is registered for industrial use with an o-toluidine content of less than 1 %. There are about 10
metallic mordants registered for industrial use which are probably prepared from o-toluidine but
also do not contain relevant o-toluidine levels (< 0.1 %) (Swiss Product Register, 2004).
2.2 Environmental Exposure and Fate
2.2.1 Sources of Environmental Exposure
o-Toluidine occurs in tobacco leaves, several vegetables, and black tea (cf Chapter 2.2.8). o-Toluidine
is ubiquitous in the human environment because it is a major component of tobacco smoke (cf
Chapters 2.2.8 and 2.3). It is a degradation intermediate of o-nitrotoluene in former ammunition
sites (cf Chapter 2.2.8). Releases of o-toluidine may occur from products like coal oil, gasoline, (cf
Chapter 2.2.8) and during its manufacturing and processing. Exposure of the environment due to
release of synthetic o-toluidine from products is not likely to occur. The following information on
environmental exposure from manufacturing and processing of o-toluidine in the Sponsor country is
available:
At all five sites in the Sponsor country o-toluidine is manufactured or processed in closed systems
The effluent concentrations from the wastewater treatment plants of these companies are below the
detection limits of 20 µg/l (production site), and below 10 µg/l (two processing sites) and below
25 µg/l (one processing site) respectively (Bayer Chemicals, 2004; BASF AG, 2004; Clariant
GmbH, 2005). For one production site in the Sponsor country only data for the sum of the toluidine
isomers are available (BASF AG, 2005).
At the Bayer production site, the exhausts from hydrogenation, distillation, and processing are
connected to thermal exhaust purification plants and air washing units. In 2000, according to the
current Official Emission Declaration, < 25 kg/a of o-toluidine was emitted into the atmosphere at
the production and processing sites (Bayer Chemicals, 2004).
At the Bayer production site, waste from the manufacturing process is incinerated in an incinerator
for hazardous wastes (Bayer Chemicals, 2004).
The wastewater from hydrogenation is stripped and the wastewater is led to the Leverkusen
industrial and municipal wastewater treatment plant. The wastewater from processing is led to the
Bayer industrial wastewater treatment plant in Brunsbuettel (Bayer Chemicals, 2004).
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