But in the six months since the start of the war, Israeli authorities have also denied or restricted access to a number of items, ranging from lifesaving medical supplies to toys to chocolate croissants.

“I think it’s unprecedented,” Shaina Low, a spokeswoman for the Norwegian Refugee Council in the Palestinian territories, said of the Israeli restrictions. “It’s just nothing that aid agencies have ever had to deal with.”

The blockages and delays, coupled with attacks on aid workers, are costing Palestinian lives, aid groups say — charges Israel denies.

Items rejected from entry into Gaza

The Washington Post reached 25 aid groups, U.N. agencies and donor countries about the kinds of aid they have tried to get into Gaza. Food, water and blankets do not require approvals, but agencies submit requests for items they think have a chance of getting rejected, such as communication equipment and sanitation or shelter items.

Pre-dispatch approvals and border inspections have been inconsistent, they said, with some items rejected in one instance but approved in others. In some cases, organizations were able to get rejections overturned upon appeal. Other requests have remained in limbo.

COGAT, the Israeli military agency responsible for coordinating relief in Gaza, said the allegations that it restricts aid are “false” and that it largely permits the entry of humanitarian supplies, subject to a security inspection.

Here is a list of items the United Nations and other aid agencies say Israeli authorities have blocked from entering Gaza at least once since Oct. 7:

• anesthetics
• animal feed
• cardiac catheters
• chemical water quality testing kits
• chocolate croissants
• crutches
• field hospital boxes
• flak jackets and helmets for aid workers
• fittings for water pipeline repair
• generators for hospitals
• green tents and sleeping bags
• maternity kits
• medical thread in reproductive health kits
• medical scissors in children’s aid kits
• microbiological water-testing kits
• mobile desalination units with solar system and generators
• nail clippers in hygiene kits
• obstetric clamps
• oxygen concentrators
• oxygen cylinders
• power supply equipment
• prefabricated shelters
• satellite communication kits
• scissors and scalpels in midwifery kits
• sleeping bags with zippers
• solar panels
• solar-powered lamps and flashlights
• solar-powered medical refrigerators
• spare parts for pumps and generators
• stone fruits
• surgical tools for doctors
• tap-stand kits for water distribution
• tent poles
• toys in wooden boxes
• ultrasound equipment
• ventilators
• water bladders
• water filters and purification tablets
• water pumps
• wheelchairs, glucose measuring devices, syringes and other medical equipment on a truck rejected for a different item
• X-ray machines

Limited scanning machines and operational hours at border inspection sites slow down the delivery of aid, according to Jamie McGoldrick, the U.N. humanitarian coordinator for the occupied Palestinian territory.

If one item is rejected during an inspection, he added, the whole truck is sent back. Earlier this year, insulin pens for children were denied entry, McGoldrick said, after a mixed-cargo truck was rejected apparently because of solar panels.

“You’d think after five and a half months of a crisis of this kind, the systems in place would be a bit more predictable and settled. In fact, they are not. And that’s why we’re struggling,” McGoldrick said.

COGAT has in turn accused U.N. agencies for delays in aid delivery. Last month, responding to a video from U.N. Secretary General António Guterres showing miles of stalled trucks at the Rafah border crossing, COGAT said on social media that the United Nations “must scale up logistics and stop blaming Israel for its own failures.”

Fewer than 1.5 percent of the total trucks have been denied entry at the crossings, COGAT said, adding that 20,900 tons of medical equipment have entered Gaza since the start of the war, including medicines for cancer patients, insulin pens, anesthetics, X-ray machines, CT imagers, and oxygen generators for hospitals.

Overall, the agency says 22,105 trucks were allowed into Gaza between Oct. 7 and Wednesday, an average of about 118 trucks per day — about a fifth of the number that entered prewar. This week, COGAT said Israel was “surging” aid into the territory, and that more than 1,200 aid trucks were inspected and transferred to Gaza over three days.

U.N. and other aid agencies say, however, that Israel still controls when they can retrieve the goods from the Gaza side of the crossings — and also must approve the routes the aid trucks take within the enclave.

Israel has maintained a land, air and sea blockade on Gaza since 2007. This has included regulating the entry of “dual-use” items into Gaza, those that are predominantly civilian in nature but could also be used militarily, such as construction materials, communications equipment and chemicals. Israel argues these restrictions are necessary to choke off Hamas’s military apparatus.

Israel’s dual-use list, when it comes to Gaza, far exceeds the internationally recognized standard for such items, aid groups say. “It includes broad categories that contain potentially thousands of items, making it very difficult to know if any specific item is on the list or not,” said Miriam Marmur, public advocacy director of the Israeli human rights group Gisha. “This has impacted, for years, many, many aspects of everyday life on the Strip.”

Since Oct. 7, Israel has imposed a complete siege, and restrictions on the kind of items that can enter have greatly expanded beyond dual-use items, many say.

One U.S. official who visited the Rafah crossing point last month described meeting with aid workers who were deeply frustrated by the seeming arbitrariness of the rejected items. They included a pallet of chocolate croissants, which was apparently blocked because the Israelis deemed them luxury foods inappropriate for a war zone, said the official, who spoke on the condition of anonymity to talk candidly about their conversations during the visit.

The review process of goods for entry is “totally arbitrary,” said Sen. Chris Van Hollen (D-Md.), who visited Rafah in January.

“When you’re turning back maternity kits and water purification tablets, that is a deliberate effort not to allow desperately needed goods into Gaza,” he said. “There’s no rational justification.”

Impact on humanitarian work

The difficulties of bringing aid into Gaza today are unprecedented, several aid workers said.

“The challenges with this, I’ve never seen in 15 years of doing this work,” said a humanitarian official, who spoke on the condition of anonymity due to the sensitivity of the work on the ground, adding that groups had begun to self-restrict. “They may not be pushing through everything they want because they know it takes up a huge amount of time for them and it’s not always going to win.”

Besides aid groups, donor countries including the United Kingdom and European Union nations have also shared their frustration.

A part of Belgium’s medical supply package was refused recently without reason, said Caroline Gennez, the country’s minister for development cooperation, adding that tons of food aid are often inadmissible because of frequent changes in rules for packaged foodstuff.

“Blocking humanitarian aid is a grave violation of international humanitarian law. Using starvation as a weapon is a war crime,” Gennez said. “This madness must end.”

These experiences and assertions have prompted a growing debate in Washington over whether the United States should suspend arms transfers to Israel, with aid groups and some Democrats calling on the Biden administration to reject Israeli claims that it is not violating international law over its restrictions on humanitarian aid and use of U.S.-supplied weapons.

“Given the current restrictions on the delivery of aid, there’s no plausible way that somebody could find that those assurances are credible and reliable,” Van Hollen said.

Abigail Hauslohner, Beatriz Rios and Lior Soroka contributed to this report.