Food safety advice has been added to the updated guidance by the Lead Association for Caterers in Education (LACA) around free school meal box provision during the COVID-19 pandemic.
Concerns about food safety were highlighted in January, alongside poor quantity and quality of the boxes meant to replace free school meals during lockdown. The Department for Education promised to review the guidance with LACA and Public Health England.
The guidance on the LACA website now advises schools to clearly label items and provide use by and best before dates, but does not contain guidance around using suitable packaging materials.
The DfE guidance has been updated but still does not contain advice for schools to provide use by and best before information, or suitable packaging materials.
CIEH president Julie Barratt said: "We are delighted to see, following pressure from EHN and EHN Extra, LACA has acted responsibly and made some improvements. However, we are still concerned that further improvements need to be made.
"We think it's very unfortunate that the DfE has not taken the opportunity to update their guidance to reflect more appropriately the way vulnerable groups ought to be protected.
"It's not just about the food provided and the nutritional quality, it's also about protecting it from risk and contamination in the way it is handled and the way it is delivered."
LACA and DfE did not comment.
Calls were renewed this week for Westminster to extend free school meals into the holidays as children across England will not receive vouchers or food boxes this week, during half term. However councils will have access to the COVID Winter Grant Scheme for food and holiday activity provision.
Free school meal coverage has been extended by the devolved governments so children in Wales, Scotland, and Northern Ireland will still be eligible to cash payments, vouchers or food boxes this week.
Campaigners have previously called for the sugar tax to be extended to pay for free school meals in England, which would also help tackle childhood obesity.