How do I know the Nuk size 3 latex pacifiers will be okay?

My baby girl is 17 months old and she is using the Gerber size 2 NUK silicone pacifiers. When she turns 18 months next month, I am planning on getting her the Gerber size 3 NUK pacifiers which are for ages 18 months to 3 years. However, they do not make the size 3 ones in silicone, they only make them in latex. I have heard that some people are allergic to latex. So how do I know that they will be okay for my baby. Or should I just keep on using the size 2 silicone ones?