When GM crops and foods were first introduced in the late 1990s, some scientists raised concerns that genetic modification was imprecise and unpredictable and could result in harm to health and the environment. They warned that:

• GM could create foods that are toxic, allergenic and less nutritious than their non-GM counterparts

• GM crops could damage vulnerable wild plant and animal populations
• GM plants cannot be recalled, but as living organisms will propagate, transmitting any damaging properties from generation to generation
• GM crops could cause irreversible alterations to the food supply, with serious consequences for the environment and human and animal health.