Assessing risk

09/2008

The heart of each chlorine factory is the electrolysis room with row upon row upon row of cells where electricity is passed through salt water to separate chlorine, caustic soda and hydrogen.

In the areas of human health and safety, research projects are underway on a wide range of topics, including:

Assessing the risks posed by individual products

Manufacturing emissions as well as monitoring data are being collected on chlorine-related chemicals with the aim of developing detailed risk assessments taking into account not only hazard but also exposure. For further informatin on this go to our sections on high production volume chemicals and marine risk assessments.

This includes examining possible risks to human health (such as occupational exposure and impact on the general public) and to the environment, including the world's oceans. The physical properties of compounds are also studied.

Controlling pollution

International regulatory authorities continue to focus on the need to control chemicals which are persistent, toxic and liable to bioaccumulate (PTBs). Where these are prone to long-range transport and deposition, they are called persistent organic pollutants (POPs). Criteria to define, identify and manage these products are being developed by industry and the authorities.

Endocrine modulators

Science underpins the chlorine sector; it is vital in assessing any risks posed by products, and is essential for sensible regulation.

The debate continues on the possible causes of many human diseases and disorders, including cancer and birth defects, and on whether men's reproductive health is declining. A controversial hypothesis suggests that such health effects could be linked with exposure to environmental oestrogens, both natural and man-made; there is a lack of agreement between scientific experts on the grounds for this theory. This is a global issue which is of interest to the whole chemical industry. Some chlorine-based compounds are alleged to be involved. Recognising the importance of addressing any issue related to product safety, the chemical industry accepts the need to fund a complete scientific investigation to provide a sound basis for regulatory decisions.

Dioxins and health effects

Despite numerous studies and major research investments, scientists have so far failed to conclusively demonstrate that exposure to dioxins in the environment causes long-term human health effects.

Dioxin is the most common name given to a group of chemical molecules called dioxins and furans, which all include chlorine atoms. Because of this, it has been claimed that banning chlorine chemistry would solve the dioxin problem. This ignores the fact that there are numerous sources of natural chlorine and chlorides, and that dioxins occur naturally too as a result of forest fires, the burning of wood and bio- mass. In addition, because they are formed as the result of incomplete combustion, some waste incinerators lacking certain design and operating features have been implicated.

Continuing improvements in environmental controls on incinerators and cleaner chemical manufacturing and waste disposal processes have resulted in a decline over more than 20 years of exposure to dioxins originating from human activity. Dioxin concentrations in the environment peaked in the 1970s and have fallen back to the levels that existed more than 50 years ago. Despite this improvement, the chemical industry is working to further reduce industrial dioxin emissions. Simultaneously, scientists are continuing research in order to better understand how dioxins act on living organisms.

Atmospheric changes

Science is central to the success of chlorine-based products.

Research has been done to evaluate global production of natural organochlorines and to provide an inventory of changes in atmospheric emissions of major reactive types of chlorine derivatives. The research analyses samples of rain, snow and ice in remote regions of both hemispheres.