They’re just as frightening as Lions and Tigers and Bears, but how much do you know about them? Are they in your medical devices?
There are two different “flavors” of latex: natural rubber latex and synthetic latex. Natural rubber latex is manufactured from a milky fluid that is primarily obtained from the rubber tree (Heva brasiliensis). Natural rubber proteins are what are responsible for allergic reactions in some people. Synthetic latex is not usually associated with allergies.  Therefore, natural rubber latex is the one the FDA is generally concerned with.
According to 21 CFR 801.437, any medical devices that contain natural rubber latex and come into contact with humans must be appropriately labeled to warn the user of possible allergic reactions.  This regulation does not forbid you from having latex in your products, but it is intended to protect the public health by providing adequate information to the users of possible risks of use.
Di-(2-ethylexyl) phthalate (DEHP) is a placsticizer (softener) that is commonly added to plastics (such as polyvinyl chloride, PVC) to make them more flexible. Plastics are used throughout the medical device industry, and as you can imagine, so are plasticizers. Since plasticizers are not chemically linked to the plastic, over time they can leach out of the plastic into solutions. 
DEHP exposure has shown negative effects in animal models, particularly on the male reproductive system. While human exposure levels and adverse effects have not been well defined, the industry recognizes DEHP as a risk that can be averted by limiting the exposure of patients to DEHP. Manufacturers can assist in mitigating risk of DEHP exposure by designing devices with alternative materials (such as ethylene vinyl acetate, silicone, polyethylene, or polyurethane). 
Bispheonol A (BPA) is a chemical that is used to manufacturer polymers, mainly polycarbonate polymers and epoxy-based enamels and coatings. Since polymeric reactions do not go entirely to completion, small residual amounts of BPA can remain in polymers and leach out over time. BPA can be found in hard plastic bottles and containers, and has mainly been of concern in food contacting products such as Tupperware, baby bottles, and linings of cans .
Much like DEHP, the there is no consensus on the health effects of BPA. There have been studies that suggest exposure to BPA can lead to reproductive and developmental issues, with fetuses, infants, and young children being the highest risk populations . In the medical device industry, BPA exposure risk is probably highest in pediatric patients who undergo cardiopulmonary bypass, and dialysis patients .
For one reason or another, many manufacturers have chosen to eliminate these materials from their products. Some have done it to mitigate potential risks to public health, while others have done it to gain a marketing advantage over their competitors. There are a lot of important things to think about when choosing your materials. Despite the controversies, if you have the opportunity to eliminate a potential risk by choosing materials that do not contain natural rubber latex, DEHP, or BPA, then I would go for it!
 Latex Allergy; OSHA; 25 Sep 2008; http://www.osha.gov/SLTC/latexallergy/index.html
 21 CFR 821.437 User labeling for devices that contain natural rubber; 1 April 2012; http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=801.437
 FDA Public Health Notification: PVC Devices Containing the Plasticizer DEHP; 12 July 2002; http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/PublicHealthNotifications/ucm062182.htm
 Bisphenol A (BPA): Use in Food Contact Application; March 30, 2012; http://www.fda.gov/newsevents/publichealthfocus/ucm064437.htm
 FDA to Test BPA Exposure from Medical Devices; E Walker; 26 Feb 2009; Washington Watch; http://www.medpagetoday.com/Washington-Watch/Washington-Watch/13022