Such work , say many , should only be done in the most secure facilities : those rated " biosafety level 4 " .
这些工作,许多人说是,都应该只在那些得到最好安全保护的,评级为“生物安全级别4级”的设施中进行。
Gr professionals who also provide advice to ministries of health and agriculture must also be aware of the sensitivities and issues related in particular to biosafety and genetically modified organisms .
However policy has existed at an international level , since at least the 19th century , with the aim of coordinating phytosanitary measures to improve biosafety over wider areas .
One big reason , they say , is that the proposals are already reviewed by the u. s. food and drug administration and institutional ethics and biosafety boards , which now have plenty of experience with the field .