Think you've got a clean kitchen? As clean as a restaurant kitchen? Chances are, it's not even close.

The results of a survey conducted by the Los Angeles County Department of Public Health (LACDPH) finds that at least one in seven home kitchens would flunk the kind of inspections that restaurants have to go through.

And that's assuming people were honest in the self-assessment Web-based questionnaire.

The survey is a unique way to examine food safety in private homes, where it's believed that the bulk of food poisonings derive. And the results are a little bit scary.

Of the 13,000 adults who completed the Internet quiz over two years, only 34 per cent received an A rating. Another 27 per cent received a B, while 14 per cent failed.

In comparison, 98 per cent of restaurants in L.A. County get A or B scores each year. And all of those facilities are physically inspected by trained food safety professionals.

The quiz included yes/no questions that simulated a restaurant inspection checklist, asking about regular food preparation practices and about the physical state of the kitchen.

Some of the questions included queries that one would expect, including: are there rats or cockroaches in your kitchen?

But other questions may have left some home-based chefs a little red-faced with embarrassment, including:

• I wash and sanitize my sponge daily
• My kitchen walls/floors/ceilings are free of any damage or deterioration such as chipped paint, holes in the wall, etc.
• I never leave leftover foods at room temperature for more than 4 hours
• When cooking big portions of food to serve later (e.g., the next day), I rapidly cool it (i.e., in an ice bath and stirring frequently, separating it into smaller portions, adding ice as an ingredient, using containers that facilitate heat transfer, etc.) and store it in my refrigerator.

The results showed:

• 27 per cent of respondents reported not storing partially cooked foods that would not be used immediately in the refrigerator before final cooking
• 28 per cent did not remove all jewelry from hands and/or did not keep fingernails trimmed when cooking
• 26 per cent reported their kitchen shelves and cabinets were not clean and free from dust
• 36 per cent said they did not have a properly working thermometer inside the refrigerator
• 9 per cent reported they had flies inside the home
• 6 per cent reported cockroaches
• 5 per cent reported rodents

The quiz was meant more as an education tool for homeowners, rather than a scientific way to assess home chefs.

The editors note that the quiz results were likely skewed by a number of factors, including the fact that people interested in food safety would have been most likely to take the quiz. In the real world, it's likely that an even smaller percentage of home kitchens would have passed the test.

The results were published Thursday in the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.