An overview of the chemistry, manufacture, environmental fate and detection of carbofuran - Carbofuran and Wildlife Poisoning: Global Perspectives and Forensic Approaches - page 5

Table 1.1 Name and headquarter location of selected companies that manufacture carbofuran
products and trade names under which they are sold

Company name Headquarter location Trade name

Agro-Chemie Hungary Chinufur

Aimco Pesticides Limited India Furacarb

Cequisa Spain Cekufuran

Makhteshim Agan Industries Israel Carbodan

Nagajura Agridar India Fury

Sanachem (Pty) Ltd South Africa Terrafuran

Sipcam Italy Carbosip, Rampart

Sanonda/Zhengzhou Pesticides Co Ltd. China Agrofuran

Information taken from The Pesticide Manual (www.pesticidemanual.com/)

However, in the United States, patents are granted for a maximum of 20 years, and Chapters 5 and 6,
for example, list other manufacturers as registrants of the product in the late 1980s, which leads
us to believe that FMC's sole patent expired sometime in the mid to late 1980s. Table 1.1 lists
other known manufacturers of carbofuran around the world. For a complete list of manufacturers of
carbofuran products, the reader is referred to the Pesticide Manual (www.pesticidemanual.com/).

1.4 Carbofuran in the environment
The dominant source of carbofuran emission to the environment is via its application as an insecti-
cide. In this context, it is sobering to consider that, in general, approximately 90% of all agricultural
pesticide applications never actually reach their target organism(s). This 'excess' is instead widely
dispersed into the environment, entering the air, soil and water (Moses, Johnson and Auger 1993).
The environmental fate and persistence of any specifi c compound is also governed by the prevailing
climate and as such differs between tropical and temperate regions (Fodor-Csorba 1998). Elevated
temperatures can lead to pesticide loss and deterioration through volatilisation (i.e., transformation
to a gas and then dissipation) and increased microbial activity. Sunlight and ultraviolet (UV) inten-
sity is also greater in tropical and subtropical regions, which again can lead to more rapid photodeg-
radation (Fodor-Csorba 1998). Such degradation and the reaction products formed (some of which
may be more toxic than the original parent compound) are then themselves transported into the
environment. The ability to identify and analyse such degradation products and metabolites is likely
to become increasingly important in the future as 'sustainable' biocide products with low ecotoxicity
are identifi ed and developed.
In soil, chemical transformation processes are infl uenced by factors such as pH, temperature, clay
content, organic matter content, moisture content, the presence of micro-organisms, and the types of
functional groups that are attached to the pesticide molecule (Lalah, Kaigwara, Getenga et al. 2001).
Chemical reactions can be catalysed by clay surfaces, metal oxides and metal ions in soil. Likewise,
the rate of chemical hydrolysis (i.e., the addition of water to a compound) occurs more rapidly
in alkaline soils than in neutral or acidic soils (Lalah, Kaigwara, Getenga et al. 2001). As such,
carbofuran tends to be more stable in acidic soils. Soil pH is indeed one of the major determinants of
pesticide persistence (see Section 3.2, Chapter 3). In addition, external environmental factors such
as wind, humidity, soil and air temperature, as well as rainfall, all infl uence the degradation and