When a pesticide product registration is cancelled, the sale and use of this product __________.

When a pesticide product registration is cancelled, the sale and use of this product must cease immediately. This is because once a registration is cancelled, the product is no longer approved for use by the regulatory agency. The agency has determined that the product either poses unacceptable risks or does not meet the necessary safety standards. As a result, all sales and usage of the product must stop to ensure compliance with safety regulations and to protect public health and the environment. In certain situations, the agency may allow for some limited use of existing stocks under specific conditions, but this generally does not equate to a blanket permission to continue sales and usage freely. The priority in these scenarios is safeguarding against any potential hazards that the cancelled product might present.