Ms Howson said: "The pain got worse and worse, I thought I was having a heart attack. I've had a collapsed lung before, and it felt a bit like that.
"Corey was terrified because he thought I was getting ill [from my condition] again, as I've had periods of six months where I've been in a wheelchair.
"I was petrified, I didn't know what was happening, and just kept thinking about my kids."
After receiving more oxygen at hospital, Ms Howson was given a chest X-ray but the results came back clear.
She said: "The doctor asked if I had been cleaning, because the paramedics mentioned a strong smell of bleach.
"He said mixing those chemicals with the hot water had given me chlorine gas poisoning. I was stunned, I couldn't believe it.
"He said that it happens far more than you'd think. He said if my son hadn't phoned for the ambulance when he did that it could have been a lot worse.
"He's really mature for his age, and I'm so grateful he didn't listen to me when I said I was fine.
"He's made a joke out of it and calls me the 'chlorine gaffe girl' and says I should leave the cleaning to the professionals.
"But it could have been so much worse. I could not be here. It could have killed me."
Ms Howson was left with a headache and a sore throat as a result of the poisoning, but was allowed return home to be with Corey and her two daughters, Evie, nine, and 11-week-old Jaymie-Leigh later that day.
She will return to the doctors to find out whether the chlorine gas poisoning has left her with any permanent side effects later this month.
Ms Howson said: "I just want to warn people. Everything I used were just normal cleaning products that you can get from Asda.
"I didn't read the small print on the bottles, but no one does really, and I just want everyone to make sure they do when they're cleaning."
