The state's CA Notify system, developed by Apple and Google, is one approach.
RELATED: California to expand smartphone COVID-19 alert tool statewide
It looks like a keyless access card commonly used at many offices. But inside is Bluetooth technology that keeps tabs on others wearing the same card. It stores who a person has been around and for how long, which are critical for contact tracing.
"What we're doing is actually giving the business visibility on who the person infected has been in proximity with in the last 20 days so that the can take action," said Matias Monges of Contact Harald. "They can isolate only a handful of people and not the whole organization."
The Emeryville law firm of Weinberg, Roger & Rosenfeld has 56 employees wearing these cards, created by Contact Harald. Just 10 days ago, it allowed administrator Jennifer Calhoun to determine who had been in proximity with an employee who had been near someone who tested positive.
RELATED: Some phones can send push alerts to users who were near those who tested positive for COVID-19
"With everyone's anxiety being very high around this, having that confidence coming back into the office and having our employees feel confident that we're taking care of them, that we're doing everything we can to be safe," she said.
To address privacy concerns, the data stays on the card until a need arises. Each tracing card costs $30. The law firm says it spent an additional $1500 to acquire the software and an iPad to manage it.
Other contact tracing systems using mobile phones have to rely on users to keep Bluetooth on and to have their phones with them at all times. The card and lanyard serve as a constant reminder to maintain proper social distancing.
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