Perfluoropropionyl fluoride

Endpoint summary

Description of key information

Four acute inhalation toxicity studies were conducted on PFPF.  The results of the studies were:

The 4-hour acute inhalation LC50 is between 100 and 200 ppm in male and female Sprague-Dawley rats (or approximately 250 ppm, based on a 1-hour exposure).

The 4-hour acute inhalation LC50 is greater than 50 ppm (LC0) in male Sprague-Dawley rats.

The 4-hour acute inhalation LC50 is greater than 300 ppm (LC0) in male Sprague-Dawley rats (or greater than 850 ppm, based on a 30-minute exposure).

The 4-hour acute inhalation LC50 is greater than 25 ppm but less than 79 ppm in mice.

Additional information

The objective of this study was to determine a 1-hour and 4-hour approximate lethal concentration (ALC) of MTDID 28783 when administered as single 1- and 4-hour whole-body inhalation exposures to rats. The test substance was administered to 6 groups of 2 male and 2 female Crl:CD®(SD) albino rats via whole-body inhalation exposure as a gas at target concentrations of 50, 100, and 200 ppm for 4 hours and at concentrations of 250, 500, and 1000 ppm for 1 hour. Mortality, clinical observations, body weights, and body weight changes were evaluated over a 14-day post-exposure observation period. Necropsies were conducted on all animals. Mortality after the 4-hour exposures was 0/4, 1/4, and 4/4 animals for the 50, 100, and 200 ppm groups, respectively. Mortality after the 1-hour exposures was 0/4, 2/4, and 3/4 animals for the 250, 500, and 1000 ppm groups, respectively. Clinical observations during the 4-hour exposures included labored respiration in the 200 ppm group; and increased respiration in the 100 and 200 ppm groups. Clinical observations 0-1 hour following the 4-hour exposures included labored respiration in the 200 ppm group; partial closure of the right eye in the 200 ppm group; and increased respiration in the 100 ppm group.

Clinical observations during the 1-hour exposures included labored respiration in the 250 and 1000 ppm groups; increased respiration in the 250 ppm group; gasping in the 250 and 1000 ppm groups; and salivation and clear material around the left eye in the 1000 ppm group. Clinical observations 0-1 hour following exposure included labored respiration in the 1000 ppm group; clear material around the nose and mouth in the 500 and 1000 ppm groups; gasping, rales, and red material around nose in the 1000 ppm group; and red material around mouth in the 500 ppm group.

Significant clinical observations for the surviving animals from the 4-hour exposures during the 14-day post-exposure observation period included of rales, labored respiration, and red material around the nose in the 100 and 200 ppm groups were considered clinically normal by study days 0, 10, and 5, respectively. Significant clinical observations for the surviving animals from the 1-hour exposure during the 14-day post-exposure observation period included rales and labored respiration in the 1000 ppm group; red material around nose in the 250, 500, and 1000 ppm groups; increased respiration in the 1000 ppm group; and decreased defecation in the 500 ppm group. All surviving animals in the 250, 500, and 1000 ppm groups were considered clinically normal by study days 1, 3, and 3, respectively.

One male in the 500 ppm group weighed 4 grams less than its initial (study day 0) body weight on study day 14. All other surviving animals surpassed their initial body weight by study day 14.

Internal macroscopic findings noted for animals that died consisted of dark red discoloration of the lungs in the 200 and 1000 ppm groups; firm lungs, lungs not fully collapsed, and small spleen in the 200 ppm group. At the scheduled necropsy, macroscopic findings noted consisted of rough surface on the spleen in the 50 ppm group and clear fluid contents in the uterus in the 1000 ppm group. There were no other internal macroscopic findings for animals at the scheduled necropsy.

Based on the results of the study, the 4 -hour acute inhalation LC50 of the test article is between 100 and 200 ppm in male and female Sprague-Dawley rats.

The acute inhalation toxicity of MTDID 28783 (clear and colorless liquid at -42C, purity 95.4%, Lot: N.B.# 159571-90-3) was evaluated in male Sprague Dawley rats. This study was a 3M custom protocol and was not intended to be compliant with GLP guidelines. The study was conducted for research and development purposes. Rats (5, male) were exposed, whole body, to MTDID 28783, administered as a gas at 50 ppm for a 4-hour exposure. Controls (5, male) were placed in a separate chamber without the exposure to the test material. Clinical observations (throughout the study) and body weights (prior to exposure, Days 1, 4-8, and 11-14) were recorded. Following Day 14, necropsies were performed on all animals (test and control). All animals survived for the duration of the study. All test animals were observed to have head shaking and slightly slower than normal respiratory rates during the 4-hour exposure period. Head shaking was noted 17 minutes into the exposure and ceased after 14 minutes. Slightly lower respiratory rates were noted 66 minutes into the exposure but stabilized within 1 minute. All animals gained weight throughout the study. Body weights were similar between test and control animals. No gross lesions were noted during necropsy. Based on the results of the study, the 4-hour LC50 (gas) of MTDID 28783 is >50 ppm.

The acute inhalation toxicity of MTDID 7908 (a gas) was evaluated in male Sprague Dawley rats following a 30 minute or 4 hour exposure. The study design followed a custom protocol.  Male rats (3/group) were whole body exposed to the test material at concentrations of 800 or 2400 ppm for 30 minutes; 280 and 850 ppm as 4-hour equivalents, respectively.  Additional male rats (3/group) were whole body exposed to the test material at concentrations of 100 or 300 ppm for 4 hours.  The rats were terminated at 14 days post-exposure.  Parameters evaluated: clinical observations, body weights, food consumption, and macroscopy.  Irregular respiration rate, lethargy and labored breathing were noted during exposure in animals exposed for 30 minutes at 800 or 2400 ppm; animals appeared normal after exposure termination.  No other abnormal clinical signs, body weight changes, food consumption changes or macroscopic observations were noted in any groups throughout the study.  The 4-hour inhalation LC50 for MTDID 7908 is considered to be greater than 300 ppm in rats.

This study evaluated the acute inhalation toxicity of perfluoropropionyl fluoride (PFPF, CAS# 422-61-7, 94.3% pure) in mice.  The test material was supplied in a gas cylinder and mice were exposed to gas atmospheres.  One mouse was exposed to 100 ppm for 2.5 hours by whole body exposure (equivalent to a 79 ppm exposure for 4 hours).  Three additional mice were exposed to 25 ppm for four hours by whole body exposure.  Control groups of identical numbers of animals were exposed to the same treatment without the addition of test article.   The day of exposure was designated Day 1.  The mice were observed for clinical signs of toxicity (including mortality, if any) for 14 days. When applicable, gross necropsy was performed at the end of day 14. Control animals were normal throughout the study.  The mouse exposed to 100 ppm for 2.5 hours had shortness of breath during the last 1.5 hours of the exposure period.  Following the exposure period the mouse appeared normal, but lost body weight on each subsequent day and died between Day 3 and 5.  A gross necropsy was not performed because the animal was found in a state of rigor mortis.  The three mice exposed to 25 ppm for 4 hours had slightly increased breathing rates during the last 10 minutes of exposure.  After exposure, these mice appeared normal and gained weight through Day 14.  Gross necropsy observations were normal for the 25 ppm-treated mice.  Based on the results obtained from this study, the four-hour inhalation lethal concentration for PFPF gas is greater than 25 ppm but less than 79 ppm in mice.

Justification for classification or non-classification

Based on the available data, PFPF meets the GHS criteria for classification as Category 2 for acute inhalation lethality.