structural:summarization
Controversy

Critics have objected to the use of genetic engineering on several grounds, including ethical, ecological and economic concerns. Many of these concerns involve GM crops and whether food produced from them is safe and what impact growing them will have on the environment. These controversies have led to litigation, international trade disputes, and protests, and to restrictive regulation of commercial products in some countries.

Accusations that scientists are " playing God " and other religious issues have been ascribed to the technology from the beginning. Other ethical issues raised include the patenting of life, the use of intellectual property rights, the level of labeling on products, control of the food supply and the objectivity of the regulatory process. Although doubts have been raised, economically most studies have found growing GM crops to be beneficial to farmers.

Gene flow between GM crops and compatible plants, along with increased use of selective herbicides, can increase the risk of " superweeds " developing. Other environmental concerns involve potential impacts on non-target organisms, including soil microbes, and an increase in secondary and resistant insect pests. Many of the environmental impacts regarding GM crops may take many years to be understood and are also evident in conventional agriculture practices. With the commercialisation of genetically modified fish there are concerns over what the environmental consequences will be if they escape.

There are three main concerns over the safety of genetically modified food: whether they may provoke an allergic reaction; whether the genes could transfer from the food into human cells; and whether the genes not approved for human consumption could outcross to other crops. There is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, but that each GM food needs to be tested on a case-by-case basis before introduction. Nonetheless, members of the public are less likely than scientists to perceive GM foods as safe.