Hundreds of workers in the Gulf Coast cleaning up BP’s oil disaster have reported symptoms of nausea, vomiting, nose bleeds, and headaches, but those “almost all have been heat related,” according to Deputy Assistant Secretary of Labor for OSHA Jordan Barab.

Barab – a former worker health and safety blogger at Firedoglake and his blog, Confined Space – says that despite widespread assumptions that workers are sick from exposure to oil, “we haven’t really found that yet.”

“We’re really looking, but haven’t found anything significant in the chemical samplings. We’re looking for people getting sick, but it tends to be overwhelmingly heat related,” Barab told Firedoglake earlier this week.

In late June, OSHA issued guidelines for worker health and safety in the Gulf, including the limited use of respirators for workers around exposed crude oil near the source of the oil gusher. This came after more than 28,000 Firedoglake activists called on BP to provide respirators for cleanup workers.

OSHA has up to 40 employees in the Gulf Coast dedicated to the oil disaster, and have conducted more than 2,000 worksite visits. Barab says the challenges OSHA faces in the Gulf are similar to those of any other workplace for which the agency is responsible, namely that they can’t be everywhere at once.

“OSHA will never be in every workplace with every worker at every moment,” said Barab. “So we’re forced to do representative sampling. We characterize work situations and do as much sampling as we can. We’re hoping that those are representative.”

While OSHA is conducting its own evaluations of worker health through site visits, agencies in states and the federal government are cobbling together reports from emergency rooms and poison control centers, as well as BP’s own reporting, that paint a dire picture of worker safety.

According to data from the Louisana Office of Public Health analyzed by Firedoglake, more than 100 workers have reported symptoms similar to that of oil exposure. More than half (59) of workers reporting health symptoms were working offshore when exposed, which is where the most concentrated oil is found in the Gulf.

Barab says Louisiana’s data is misleading. Louisiana is “cataloguing, not describing” its data, which makes it look like people are sick from oil exposure, when in fact, according to OSHA’s analyses, most workers are actually sick from heat. NIOSH, part of the CDC, is working with Louisiana to include “more precises causes” for illnesses reported in its data.

OSHA says that “workers are supposed to be reporting symptoms.” While there have been reports that workers are holding back information for fear of being fired, OSHA is doing what it can to ensure workers are protected and that they know they can freely and confidentially report any problem.

As for BP’s cooperation on worker safety, OSHA is satisfied – much more than when OSHA’s head, David Michaels, complained of BP’s lack of effort on the topic in late May. ”At this point, we’re getting along fairly well with BP. Even though a lot of what we’re aksing them to do we dont have standards for, BP is pretty much doing what they want them to do,” said Barab. “When they’re not, with a little pressure, they do it.”

Any problems with worker safety in the Gulf are actually “with people who see this as another 9/11, another World Trade Center,” said Barab. “The issues are not between us and BP.”