Man warns pet owners after fish tank releases 'second deadliest' poison, hospitalizes 10

At first, Chris Matthews thought a flu bug had hit his entire family last week when they started to feel nauseous and experience eye problems at the same time. But when the family's two dogs started to show symptoms, Matthews knew something was wrong.

Matthews had cleaned out the aquarium inside his house in Steventon, England, a day prior. The 27-year-old was transferring rocks and other items from the fish tank into another container, so he could clean each item individually.

During the process, the pet owner unknowningly scrubbed a piece of coral, releasing palytoxin into the air, SWNS reports. Palytoxin is "a potentially life-threatening toxin that can act via dermal, inhalation, and oral routes of exposure," according to the CDC.

"We couldn't regulate our temperature, we were struggling to breathe and coughing, We woke up the next morning feeling groggy but initially put it down to flu."

— Chris Matthews

When he was finished power cleaning the tank, Matthews shut the door and went to bed. The next day, Matthews and five others in the home started developing symptoms "as bad as pneumonia."

"We couldn't regulate our temperature, we were struggling to breathe and coughing," he told SWNS on Thursday. "We woke up the next morning feeling groggy but initially put it down to flu."

Realizing coral may have been the culprit, Matthews called the local police -- and received a massive emergency response.

Dozens of emergency officers, a hazardous area response team and ambulances surrounded the home, the BBC reports. Crews with Oxfordshire Fire and Rescue followed instructions from the Public Health England to safely remove the toxic coral from the house.

Matthews, his girlfriend, mother, father, sister and her boyfriend, and four firefighters were rushed to the hospital for treatment after inhaling the poisonous fumes. Luckily, they got out just in time.

"If we had spent another night in that bedroom our lives would have been in danger," Matthews said.

British scientist and TV presenter Mike Leahy stumbled upon the scene while visiting his mom, who lives in the same neighborhood.

"Went for a cuppa with Mum. When I left confronted by this. Trapped within police cordon," he tweeted, along with a photo of police cruisers. "Palytoxin incident due to a neighbour cleaning his coral tank. Second deadliest naturally occurring toxin in the world (allegedly) but rarely kills, & only if eaten! Over-reaction?"

While palytoxin may be more dangerous when ingested, there can still be serious side effects simply by breathing in the fumes such as a disruption of "normal corneal function" and "irreversible blindness," the CDC warns.

Matthews, who has been taking care of tropical fish for over a decade, said he had no idea his simple chore could cause such damage.

"I knew about palytoxin, which can kill you if ingested, and that coral can cause things like rashes if you don't handle it carefully but I had no idea taking the pulsing xenia (coral) out of the water could make the toxin airborne," he said.

Now he's warning other pet owners in hopes of preventing a situation like his from ever occurring again.

"I want to use this experience to educate people about the risks and the measures people need to take," Matthews said. "I've seen the coral described as 'exotic' but it is actually one of the most common around. It's a pest coral called pulsing xenia that you grow in areas where you can't get anything else to thrive."

Officials tented the house to rid it of the poison and the family was able to return, though Matthews notes he plans to be much more careful when he cares after his fish in the future.