WASHINGTON (Reuters) -Prices for long-lasting U.S. consumer and personal goods increased in September, data from OpenBrand showed on Thursday, though the boost from import tariffs appeared to be fading.

A partial U.S. government shutdown, now in its second week, has caused the suspension of official economic data collection and publication, including September's Consumer Price Index report that was due to be released next Wednesday. 

That has left investors scanning private data for clues on the state of the labor market and inflation.

Data analytics firm OpenBrand said its Consumer Price Index for durable and personal goods increased 0.58% month-on-month after rising 0.45% in August. The price measure leverages OpenBrand's library of durable and personal goods pricing, promotion and availability covering more than 400,000 products. 

Last month's rise was driven by surges in the prices for communication, personal care and recreational products, attributed to the end of the "de minimis" exemption in August, which allowed items valued under $800 to be imported duty-free.

"The elimination of this exemption would specifically impact products that are physically smaller and could be packaged in bundles, such as phones, computers, gaming consoles and personal care items," said Ralph McLaughlin, OpenBrand chief economist. "It turns out, these are the product groups we are seeing the most price acceleration in."

But prices for appliances were unchanged after rising solidly in August. Home improvement goods price gains slowed.

"Large-sized goods ... such as appliances and outdoor power equipment are actually seeing price growth cooling, suggesting that the impacts of tariffs implemented earlier in the year have already been passed through and aren't leading to new inflation in these groups," said McLaughlin.

That is a welcome development and would support some economists' views that the inflationary effects of President Donald Trump's sweeping tariffs would be short-lived. Consumer inflation accelerated in August as businesses passed on higher costs from the import duties.