Seashell, you would have just as much basis for stating that:
"look, maybe even a small quantity of broccoli is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
"look, maybe even a small quantity of chocolate is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
"look, maybe even a small quantity of herbal tea is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
"look, maybe even a small quantity of lemonade is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
"look, maybe even a small quantity of meat is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
"look, maybe even a small quantity of rice is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
"look, maybe even a small quantity of artificial sweetner is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
"look, maybe even a small quantity of artificial flavouring is toxic to baby, nobody knows for sure, but in the meantime it's my choice and I choose to take that risk".
etc. Bet you can't prove any of those things are safe. Is your diet restricted to organic produce? Even then how can you know everything you eat is safe? Do you sometimes breath in fumes from cars
In practise most of us draw the line somewhere. We can't live in a bubble of pure air, eating and drinking only things that have been proven safe, so we avoid anything where there is evidence to show it is harmful. No evidence means no moral dilemma.