I just Googled Sevin MSDS's and I got hundreds of hits all saying relatively the same thing. I read many of them, and here is a sample of what they all say:
Tech Pac, LLC - July 2001
SECTION 3 - HEALTH HAZARD DATA
A creamy, tan, odorless liquid:
* Harmful if swallowed.
* Extremely toxic to aquatic and estuarine invertebrates.
* Highly toxic to bees.
* Causes injury to Boston Ivy, Virginia Creeper and Maidenhair fern. During early season, may injure Virginia and Sand pines.
ROUTE(S) OF ENTRY: Ingestion
EYES: May cause minimal irritation.
SKIN: May cause slight irritation.
INGESTION: Harmful if swallowed.
SIGNS AND SYMPTOMS: Harmful if ingested. This product causes reversible cholinesterase inhibition. Repeated overexposure may cause more severe cholinesterase inhibition with more pronounced signs and symptoms. May lead to rapid onset of nausea, vomiting, diarrhea, abdominal pain, involuntary shaking, excess salivation, pinpoint pupils, blurred vision, profuse sweating, temporary paralysis, respiratory depression, and convulsions.
I guess we all have to be responsible for ourselves in the end. Read the data, and with our intelligent and rational minds, come to our own conclusions as to what to think.
I for one have no intention of ever using Sevin in my gardening, and can only hope that others will be just as responsible.