Survey finds many fridges far from frigid

Food safety official Diane Robinson was shocked to find that her family's fridge was among many not keeping food cold enough.

"I was a bit horrified, especially as I work for the Food Safety Authority. I thought I was being quite good, keeping my fridge at possibly a cold temperature," Ms Robinson said yesterday.

But when she put a thermometer inside her ageing fridge, she found it was running at 9C. She turned the temperature down and it now stays between 4C and 6C.

She does not think she, her husband or their two children caught food poisoning as a result of the higher temperature.

A survey of 127 fridges nationally for the authority and other groups with an interest in food safety found that a third had average air temperatures above 5C. Four had averages above 9C and the highest single recording was 18C.

The authority says refrigeration is among the most important ways of keeping food safe to avoid becoming one of the 119,000 New Zealanders each year who suffer foodborne illness. New Zealand's food poisoning rate is the highest in the developed world and no one knows why.

The survey was done by the Institute of Environmental Science and Research, which found some people were confused by fridge temperature dials. It recommends using fridge thermometers. They can cost more than $20, should be placed on the fridge's top shelf and be read first thing in the morning.

ESR microbiologist Rosemary Whyte said new fridges in the survey were as likely as old ones to be running in the "danger" zone of 8C or above. Some had meat sitting where it could drip onto ready-to-eat foods.

She said bacteria like salmonella were killed by thorough cooking. People could cope with a few salmonella bacteria on foods eaten raw, like lettuce or apples, but would become sick from the hundreds of thousands that could grow in fridges at the danger temperatures.

These fridges could also permit the proliferation of bacteria in left-overs like rice or casseroles, despite their being cooked foods.

Cooling food quickly in small containers reduced the risk, she said.

The authority published the fridge survey as part of Foodsafe Week, which emphasises the 4Cs food rule: clean, cook, cover and chill.

Turn it down

* 1C to 5C - recommended temperature to prevent most bacterial growth that can cause food poisoning
* 18C - highest temperature recorded in survey of NZ home fridges