Can employers require employees to search the internet in order to view or obtain SDSs?

No. OSHA has always required employers to have a site-specific inventory with no barriers to access. In a directive from July 9, 2015, OSHA plainly spells out that requiring an Internet search is not a compliant way to provide (M)SDS information to employees, but off-site/web-based SDS providers are compliant. See the page numbered 63 here (this is on the 68th page of the PDF).

DIRECTIVE NUMBER: CPL 02-02-079
EFFECTIVE DATE: July 9, 2015
SUBJECT: Inspection Procedures for the Hazard Communication Standard (HCS 2012)

Maintenance of SDSs in electronic format.

• The employer must not require employees to perform an Internet search (e.g., Google®, Yahoo®) to view/obtain the SDS. The employer may make SDSs available to employees on a company website or contract with an off-site/web-based SDS service provider.