How to Test for Mold or Mildew

Mold and mildew are common sights in many homes.

Do-it-yourself home mold testing kits at department and home improvement stores nationwide. With home mold testing kits, you have different options for collecting your mold sample. The kit comes with a petri dish for which to collect the sample in, along with three methods you will use to collect the sample. Once you have collected the sample, simply ship it to the lab in the included envelope. Depending on the brand of testing kit you purchased, you may need to pay a small fee for the lab to test your results.

Things You'll Need

• Home mold testing kit
• Tape

Instructions

Setting Up The Petri Dish

1. Open the mold test kit package and read all directions and warnings in the instruction manual.

2. Place the open petri dish that came in the middle of the room on a level surface. The sticky side should be facing up. Be carefully not to touch the inside of the petri dish.

3. Remove the lid from the dish. Pour the mold medium into the petri dish and replace the lid. Gently move the petri dish in a swirling motion so the liquid has completely covered the bottom of the dish. Leave the petri dish in the middle of the room to harden for one hour.

Visual Sampling Method

1. Swap the mold with the included sterile swab. Wipe the tip of the swab across the mold growth. The mold must adhere to the swab.

2. Remove the lid of the petri dish.

3. Wipe the mold sample that you just collected with the swab across the middle of the petri dish. The mold sample has to stick to the inside of the dish.

4. Secure the lid back onto the petri dish.

HVAC Air Sampling Method

1. Tape the open petri dish against an open air vent. Close all the other air vents that are connected to the system.

2. Turn the fan on high for about 10 minutes. The forced air has to hit the inside of the petri dish to collect the sample.

3. Remove the petri dish from the vent and replace the lid.

4. Leave the petri dish on a level surface to incubate for 48 hours.

5. Check the dish after 72 hours and then again, at 96 hours for signs of mold growing. If mold begins to grow inside the dish, the sample can be sent to the lab. If no mold is growing then there is no need to send the samples.

Settling Plate Method

1. Remove the lid from the petri dish.

2. Set the dish on a level surface in the area you want to test for mold.

3. Leave the dish in the area with the lid off for 1 hour.

4. Replace the lid and allow the dish to incubate for 48 hours. Check at 48, 72 and 96 hours for signs of mold growth. If signs of mold are positive send the sample to the lab for processing. If there are no signs of mold, discard the petri dish.

References

• ProLabInc.com: Professional Mold Test Kit Instructions
• IAQM.com: Mold Testing and Air Quality Testing
• Black-Mold.com: Mold Testing and Test Kits
• Mold Inspector: Mold Testing Methods
• Mold Testing Lab: Mold Testing Instructions